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Maia
(maia) - MLife

Locale: Rocky Mountains
The Evolution of a Winter Stove - Part 3 on 07/16/2013 19:31:14 MDT Print View

Companion forum thread to:

The Evolution of a Winter Stove - Part 3

Nick Gatel
(ngatel) - MLife

Locale: Southern California
Re: The Evolution of a Winter Stove - Part 3 on 07/16/2013 20:00:44 MDT Print View

I must have missed it. What is the final weight of the entire stove?

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: The Evolution of a Winter Stove - Part 3 on 07/16/2013 23:39:29 MDT Print View

Hi Nick

FMS-300T version with centre-support legs: 85 g complete
FMS-116T version with centre-support legs: 89 g complete

Change to tripod legs with 1 mm aluminium: add 'a few grams', exact detail uncertain at present.

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Legs: centre-support vs tripod on 07/16/2013 23:44:46 MDT Print View

Hi all

Following comments in the part 2 thread, I have been looking again at the question of centre-support legs vs genuine tripod legs. Making tripod legs (no centre-support) out of 0.8 mm aluminium is a bit risky imho. I have done it, but they can bend if treated roughly. (Yes, you can straighten them many times, but ...)

So I am looking at using 1.0 mm aluminium sheet for tripod legs. This will be stiffer. However, I haven't made them up yet so I can't say what the weight penalty might be. As indicated above, it will probably be 'a few grams'. I will update as soon as I have a definite weight.

Cheers

Nick Gatel
(ngatel) - MLife

Locale: Southern California
Re: Legs: centre-support vs tripod on 07/17/2013 00:11:23 MDT Print View

We don't speak metric in California, but we may when we complete our conversion to Spanish.

But my interpretor tells me that 89g is less than half the weight of a WindPro II, which runs about $99 with windscreen and reflector base and a plastic canister stand.

Windscreen, reflector and stand are additional weight.

samuel fonteneau
(samol) - M
stove on 07/17/2013 03:13:47 MDT Print View

Thanks again Roger for that great post. Seeing all the clever work you did, I'm very interested in testing one.
Regards
Samuel

Edited by samol on 07/17/2013 03:20:06 MDT.

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
The Evolution of a Winter Stove - Part 3 on 07/17/2013 04:54:16 MDT Print View

Roger, Well Done!

As much as I dislike canister stoves, I would be willing to "test" one in the ADK's. (Though I will be out of commision for a few weeks as my ribs heal from a slip on some slipery rocks up there.)I'll contact you at your e-mail.

One thing that strikes me is the center support for the unit. This could easily be supplied by increasing the length of the lower mounting screw used for attaching the legs.

Using a standard vortex style burner is a great idea. I might behoove you to make available both topper set ups and the winter stove set up if you have to buy the burners anyway.

Well engineered and well documented.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: The Evolution of a Winter Stove - Part 3 on 07/17/2013 05:31:15 MDT Print View

Hi James

No rush - I am still making all the parts. Time for ribs to heal!

> supplied by increasing the length of the lower mounting screw used for attaching the legs.
Hum, yes, but the screw would then be 25 mm long (~1"). It might look a bit strange... Dunno.

> I might behoove you to make available both topper set ups and the winter stove set up
> if you have to buy the burners anyway.
Sorry - not understood???
Do you mean include the burner body from the original stove? That's easy to do, but you then have to be happy doing a bit of engineering to strip and rebuild.

Cheers

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Re: The Evolution of a Winter Stove - Part 3 on 07/17/2013 06:00:11 MDT Print View

>> I might behoove you to make available both topper set ups and the winter stove >set up
>> if you have to buy the burners anyway.
>Sorry - not understood???
>Do you mean include the burner body from the original stove? That's easy to do, but >you then have to be happy doing a bit of engineering to strip and rebuild.

Yes. I do not mind a bit of tinkering. I am sure it is not beyond most. But, as you say, putting down a white bandana to hold the parts would help.

1" screw? Well, the bears won't care what it looks like. I was thinking that you could reduce the amount of metal in the legs...

Anyway, PM sent at your AU address.

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Re: Legs: centre-support vs tripod on 07/17/2013 06:32:07 MDT Print View

>We don't speak metric in California, but we may when we complete our conversion to >Spanish.

>But my interpretor tells me that 89g is less than half the weight of a WindPro II, >which runs about $99 with windscreen and reflector base and a plastic canister >stand.

>Windscreen, reflector and stand are additional weight.

Well, for those that do not speak metric, 90g is about 3-1/4oz. Ultra LIGHT...good enough to use for all excursions, even if you don't do much winter camping.

The primary benefits are being able to couple the stove with a Caldera Cone (Sidewinder and the like) for increased efficiency, since it is made of heat tolerant materials. The 3-4oz wind screen will eventually pay off on hikes of about a weeks length. I use about 2 liters per day, breakfast and supper. This will improve efficiency from a shade over a quarter ounce per liter to about a fifth ounce per liter. This means that two canisters will last a full two weeks with some to spare. In the past, three 100g canisters(~4oz) were required (since I also do a bit of cooking.) By using two, it drops ~7oz (canister and fuel) making it the lightest most efficient setup to carry for up to 19 days(without cooking, just boiling water.) Even for others, they could consider using a cone, provided you light the stove before putting the cone over it.

Like any other well designed piece of camp gear, simple and flexible.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Legs: centre-support vs tripod on 07/17/2013 07:58:07 MDT Print View

Nice series of articles. I wish other manufacturers would go into such detail about how their products were designed.

3 1/4 ounces - that's just a little bit more than upright canister stoves. That's always been a big negative for me about inverted stoves.

When the burner is so close to the ground like yours, you don't need a windscreen so much. And the windscreen can be smaller/lighter.

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Re: Legs: centre-support vs tripod on 07/17/2013 09:18:10 MDT Print View

"We don't speak metric in California, but we may when we complete our conversion to Spanish."

Nick, you do speak metric. You have a metric crescent wrench, don't you?

--B.G.--

Nick Gatel
(ngatel) - MLife

Locale: Southern California
Re: Re: Re: Legs: centre-support vs tripod on 07/17/2013 09:27:24 MDT Print View

"Nick, you do speak metric. You have a metric crescent wrench, don't you?"

No, my crescent wrenches are measured in inches of length :)

Michael Martin
(MikeMartin) - BPL Staff - MLife

Locale: North Idaho
Xtreme rod on 07/17/2013 11:23:22 MDT Print View

Nice work, Roger!

I've long been puzzled by the rod in the Coleman Xtreme fuel tube.
You mentioned that the rod likely performed the same function as yours -- fuel spreader and heat exchanger.

But in the Xtreme, the rod is upstream of the pre-heat loop, and it is physically (and thermally) far from the flame heat source. Don't these characteristics severely limit its usefulness in smoothly vaporizing the fuel?

Best Regards,

-Mike

Ross Bleakney
(rossbleakney) - MLife

Locale: Cascades
Re: Re: Re: The Evolution of a Winter Stove - Part 3 on 07/17/2013 14:11:18 MDT Print View

Wow! I'll admit, I skimmed the article, but this part is huge:

FMS-300T version with centre-support legs: 85 g complete
FMS-116T version with centre-support legs: 89 g complete

A winter stove for around three ounces? Sounds great to me. As mentioned, this is great even if you don't do any winter camping. The fantastic part about the stove is that you can build a windscreen without worrying about overheating the canister. This is much simpler (or much safer) than most canister based windscreens. A little foil and you have a rock solid, safe, windproof stove for less than four ounces. Excellent.

Monty Montana
(TarasBulba) - MLife

Locale: Rocky Mountains
Re: The Evolution of a Winter Stove - Part 3 on 07/17/2013 16:22:39 MDT Print View

Hi Roger!

I'd be interested in one of your stoves to test. I have quite a collection that I've accumulated over the years beginning with the original Gerry canister stove from the '60s...in fact I still have some of the canisters that go with it. They are sans the Lindel valve, instead they have a bulbous rubber thingy that the inlet tube penetrated. Seemed to work ok for the years that I used it. Anyway, I'll send you my PM.

Thanks for your insightful and professional work on this!

USA Duane Hall
(hikerduane) - F

Locale: Extreme northern Sierra Nevada
The Evolution of a Winter Stove - Part 3 on 07/17/2013 17:55:41 MDT Print View

I guess I'll have to pony up the funds to become a paying member to see what the fuss is about. Is there a time frame for when the stove will be available to us who camp year round? It sure would be nice to shave some more weight off my winter gear. I collect stoves, so this might be neat to get ahold of.
Duane

Oliver Nissen
(olivernissen) - MLife

Locale: Yorkshire Dales
Canister connector 3D printable on 07/17/2013 18:03:12 MDT Print View

Was/could a 3d printer be used to make the canister connector? (I'm learning Rhino (CAD) at work at the moment and I've simply got to put these skills to use somewhere in real life!)

This is fascinating and inspiring stuff Roger - many thanks for your excellent work.

Jim Colten
(jcolten)

Locale: MN
Re: The Evolution of a Winter Stove - Part 3 on 07/17/2013 19:51:37 MDT Print View

Very nice, Roger.

89g ... 3.14oz ... the pi stove!

Some other dimensions would be nice (height, what diameter circles would circumscribe legs and pot supports)

Perhaps a photo of the stove folded up for packing?

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Xtreme rod on 07/17/2013 20:03:13 MDT Print View

Hi Mike

> You mentioned that the rod likely performed the same function as yours -- fuel
> spreader and heat exchanger.
> But in the Xtreme, the rod is upstream of the pre-heat loop, and it is physically
> (and thermally) far from the flame heat source. Don't these characteristics severely
> limit its usefulness in smoothly vaporizing the fuel?

Ha! Fire up an Xtreme and see how hot the straight brass bit with the rod in it gets. The top of the loop is in the flame, and probabaly gets to 400 C. The upstream section won't get that hot, but it will be well over 0 C. And butane boils at 0 C. Butane and propane are not the same as white gas and kero.

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: Legs: centre-support vs tripod on 07/17/2013 20:08:05 MDT Print View

> The primary benefits are being able to couple the stove with a Caldera Cone

Please note that I do not recommend ever enclosing any canister stove, remote or upright, in a 360 degree windshield. The Caldera Cone is fine for an alky, but a canister stove generates a lot more heat and uses a lot more oxygen. Just don't do it!

I do recommend a 3/4 windshield, sitting about 20 mm from the pot, and coming 1/2 way up the side of the pot. You need room for fresh air to get in and for the hot air to get out - for both uprights and remotes.

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: The Evolution of a Winter Stove - Part 3 on 07/17/2013 20:11:09 MDT Print View

> Is there a time frame for when the stove will be available to us who camp year round?

I have a few of the FMS-116T stoves here for immediate sale. I am still making a larger batch of the FMS-300 stoves. That will take some weeks yet to complete. No promises, and no payments accepted until I can ship.

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Canister connector 3D printable on 07/17/2013 20:14:29 MDT Print View

> Was/could a 3d printer be used to make the canister connector?
No and no.

No 3D printer generates a surface smooth enough for O-rings. Post-machining would be needed.
The cycle time to print one unit would be many hours, at least as far as I know. That's too slow.

Injection moulding is possible, but even so not simple. Plastic shrinks on cooling, especially on lumpy bits. Thin shells are OK, but this is not a thin shell.

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: The Evolution of a Winter Stove - Part 3 on 07/17/2013 20:17:42 MDT Print View

> what diameter circles would circumscribe legs and pot supports)
Legs: 130 mm circle diameter.
Pot supports FMS116T: 110 mm
Pot supports FMS-300T: 82 mm
Pot supports are exactly the same as for the upright stoves.

Folded up photo - OK, coming.

Cheers

Ross Bleakney
(rossbleakney) - MLife

Locale: Cascades
Re: Re: Re: Re: Legs: centre-support vs tripod on 07/17/2013 20:29:12 MDT Print View

>> The primary benefits are being able to couple the stove with a Caldera Cone

> Please note that I do not recommend ever enclosing any canister stove, remote or upright, in a 360 degree windshield. The Caldera Cone is fine for an alky, but a canister stove generates a lot more heat and uses a lot more oxygen. Just don't do it!

> I do recommend a 3/4 windshield, sitting about 20 mm from the pot, and coming 1/2 way up the side of the pot. You need room for fresh air to get in and for the hot air to get out - for both uprights and remotes.

I agree. A Caldera Cone concentrates the heat and supports the cook pot. These aren't necessary for a canister stove. Concentrating the heat in an alcohol (or wood) stove makes it work like a well engineered wood stove; the heat from the fire makes the fuel burn more efficiently. In this case, it is completely unnecessary. Supporting the stove is also unnecessary.

But a huge advantage of this design over an upright canister stove is that you can easily isolate the canister from the windscreen. This makes a wind screen a lot safer. You need to have a hole to let in sufficient air, but that is about it. Otherwise, the windscreen will help separate the burner from the canister. In other words, with this design, a windscreen makes the stove safer; with an upright canister, a windscreen around the entire apparatus makes it more dangerous. This means that to be really safe with an upright, you have to design a windscreen which goes between the canister and the burner, which is a pain the butt to build (a previous article describes how to make one).

Michael Martin
(MikeMartin) - BPL Staff - MLife

Locale: North Idaho
Re: Xtreme rod (and super secret winter stove technique) on 07/17/2013 20:30:16 MDT Print View

Ahhh, that makes sense. Thanks, Roger. I sold my Xtreme years ago when it became hard to find fuel so I haven't had one in my hands for a while. :-)

Like you, I've been trying to find/build the "perfect" winter stove for almost a decade. I've finally settled on a regular old sit-on-top canister stove with a bit of super secret tricky technique involved. ;-)

The trick is to stomp out a snowpit, say, 50cm in diameter and 50cm deep. I make sure the canister is prewarmed with body heat to get the fuel to initially vaporize. I lower the stove into the pit, light it, and let her rip. The volume of the pit is small enough that the stove heats it to 40-50F even when the outside temp is as low as -15F. (I've verified this with thermometers). The snow also buffers the pit temp by melting if it gets too warm, reducing the chance of thermal runaway. If it's windy, I'll partially cover the pit with a sleeping pad while cooking. The canister stays warm enough in the pit (well above 0C) to easily vaporize the fuel. The canister itself is plenty stable on the compacted snow, so I don't need any kind of stove platform. The pit makes a superb windscreen, so I don't need an aluminum one like I would with a remote canister stove.

Winter Stove Snow Pit

I've used this technique snow camping since 2007. I don't know what the lower ambient temp limit is, but I've used it successfully down to -15F with my old, faithful Giga stove and down to -5F with a Jetboil Sol. The Jetboil works particularly well as all the parts are connected and it's easy to lower into the pit. It does waste less heat than the Giga, though, so doesn't warm the pit as much and likely has a higher low-temp limit.

Cheers,

-Mike

Disclaimer: The above describes my personal stove technique. There are risks such as CO emissions in a reduced-oxygen pit, possible canister overheating/explosion, weather conditions that make it impossible to use, and the risk of the system failing and leaving you with no working stove system. Attempt at your own risk.

Edited by MikeMartin on 07/18/2013 01:11:06 MDT.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Xtreme rod (and super secret winter stove technique) on 07/18/2013 00:56:32 MDT Print View

Hi Mike

Stove pit ...
I learn something new every day!

Mind you, stomping a hole that deep in Australian snow might be a bit more difficult. It tends to be horribly solid. Even so, NEAT!

Cheers

Michael Gillenwater
(mwgillenwater) - M

Locale: Seattle area
Re: Re: Xtreme rod (and super secret winter stove technique) on 07/18/2013 01:33:31 MDT Print View

I'd be a little worried of the CO output of this setup.

Franco Darioli
(Franco) - M

Locale: Melbourne
The Evolution of a Winter Stove - Part 3 on 07/18/2013 02:43:32 MDT Print View

Michael,
Very simple , very clever... after all that is how a snow cave/igloo works.
Thanks

Just Bill Townsend
(Olmanwilly) - MLife

Locale: Midwest
Good work on 07/18/2013 08:37:33 MDT Print View

For us non-mountain folk, with your low profile is a true windscreen needed? I used to just lay my pack (or myself) on the windward side when the powermax stove fuel was still available here in the us. In snow, I use my caldera as a wind screen, just not closed up, I simply flip it over and jamb an inch or so of it into the snow/dirt leaving it open like a normal screen, got sick of using other alternatives. Been looking for a well thoughtout, and what appears to be a "universal" canister stove, weight is good for the type of stove, an ounce extra (if that) to use any brand canister you find is worth it. Well done Roger!

peter vacco
(fluff@inreach.com) - M

Locale: no. california
Re: Re: Re: The Evolution of a Winter Stove - Part 3 on 07/18/2013 09:05:44 MDT Print View

FANTASTIC !

all i can add is that if one desireth to deburr plastic parts, a fast way is to dust them with a propane torch flame.

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Good work on 07/18/2013 10:14:30 MDT Print View

Hi Bill,
Yes, wind screens are still necessary. They actually serve two purposes.
1) Shield from winds
2) Trap and concentrate heat output from the stove

Ignoring the first part 1) above, the second part is what is missed. Rather than distributing heat in a 180 degree arc, roughly speaking, it is trapped and sent back to heat the pot. As a corollary, any heat lost around the edges of the pot is also reflected back to the pot. Heat is produced in two parts: convective and through infrared radiation. Convective heating is through exhaust products and heated air that is not combusted. Infrared radiation acounts for a large portion, though.

Discussing convectition first:
I do not agree with a strict 3/4" gap around the top. This allows too much heat to be lost for no productive purpose. Conversly, too narrow of a gap will form a heat "puddle". The puddle will force heat down, into the combustion and stove. This is not what we are trying to heat, rather the pot, and what it contains, is the target. This will also increase CO production.

From this reasoning, I believe that a variable gap is needed. Depending on the setting of heat output you are using, anything between a 1/4" (on very low) to 3/4" (on high.) This will match the combustion products flow rate with their actual production. This assumes that air input is about 3-5 times exhaust output. Input is less important than output, however, so a good sized opening larger than needed will always work well. It also allows the air to cool the lower stove components.

Also, not all the heat is transfered upon contact with the pot. Some will be, some will not. Some will be picked up from the pot. This is usually carried away in the flow.

For infrared or radiative heating, using a wind screen made of aluminum or some reflective material alows the radiation to be reflected back to the pot rather than lost. Painting your pot black helps with this.

Using windscreens helps by about 25-30% given still air. In winds, they will help a lot more.

E J
(mountainwalker) - MLife

Locale: SF Bay Area & New England
Beautiful work Roger; TP jet filter and moisture, maintenance on 07/18/2013 12:08:23 MDT Print View

Beautiful work Roger, along with an excellent article on the product development.

Is there any chance the toilet paper filter could be compromised by moisture from high humidity or water from rain getting into the jet and deforming the filter?

Should the TP filter be proactively changed every X number of uses?

What would be a sign that the TP filter has been compromised (allowing gas to flow through but not catching contaminants)?

Forrest G McCarthy
(forrestmccarthy) - MLife

Locale: Planet Earth
Carbon Composite Gas Cylinder on 07/18/2013 12:28:29 MDT Print View

Cool looking stove. The next step is producing a reusable ultra-light fuel cylinder like the carbon composite cylinders used for paint ball guns and oxygen on Everest.

Carbon composite cylinders are already in production. Designing a lightweight DOT approved valve is the crux.

http://www.luxfercylinders.com/products/alternative-fuel-cylinders/443-type-3-alternative-fuel-cylinder-specifications

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Good work on 07/18/2013 17:21:20 MDT Print View

Hi Bill

> For us non-mountain folk, with your low profile is a true windscreen needed?
There's no magic here, just two points to watch.
* If the wind blows the flames sideways much, they won't be heating the pot.
* If the wind blows the hot air away, it won't be heating the sides of the pot either.

For that matter, what James wrote is equally appropriate. So anything which protects the stove is fine. Yes, I have used rocks, packs, boxes etc instead. But the extra IR reflection from a metal windshield adds a bit.

> I simply flip it over and jamb an inch or so of it into the snow
Um ... that's rather clever!

Cheers

Edited by rcaffin on 07/18/2013 17:23:03 MDT.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Beautiful work Roger; TP jet filter and moisture, maintenance on 07/18/2013 17:29:27 MDT Print View

Hi EJ

> any chance the toilet paper filter could be compromised by moisture from high
> humidity or water from rain getting into the jet and deforming the filter?
Um ... if you are getting rain inside the burner tube and through the jet, you may be taking outside cooking a bit TOO far! Humidity - nah, wouldn't worry. It will dry off pretty quick when the stove is running.

> Should the TP filter be proactively changed every X number of uses?
The ideal answer might be yes, but ... what is X?
If the canister is very clean (eg Coleman powermax) then X=100 is reasonable.
But if the canister is one of those Chinese ones I tried to use (once), then X < 1. The Chinese canister was full of very fine dust, and everything blocked immediately.

> What would be a sign that the TP filter has been compromised
Hum ... if you can't get a decent gas flow, then the TP might be rather blocked. Bad (dirty) canister.

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Carbon Composite Gas Cylinder on 07/18/2013 17:36:45 MDT Print View

> Carbon composite cylinders are already in production. Designing a lightweight DOT
> approved valve is the crux.

I suggest that using a Lindal valve is the OBVIOUS solution here. That gives compatibility with every other canister AND stove on the market. Otherwise you would have cylinders with no stoves.

In addition, you might then be able to get cylinders rated for 100% propane, like the existing Sievert ones. Oh boy, winter fuel!!!!

Cheers

Josh Brock
(needsAbath)

Locale: Outside
fire maple model on 07/18/2013 19:51:29 MDT Print View

I just sent the link to Fire Maple Stove company and they are going to have a production model of this soon for half the cost.....JK

but seriously how long do you think it will take them to completely steal this stove? Given that some of the parts are already theirs and the excellent detail in which the engineering is described.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: fire maple model on 07/18/2013 22:44:12 MDT Print View

> how long do you think it will take them to completely steal this stove?
I have no idea.
Yes, I use a Fire Maple burner, and I know the designer at Fire Maple. But my article does not specify ALL the fine details which are essential to making the stove work.

If they want to negotiate with me later on, that's fine.

Cheers

Josh Brock
(needsAbath)

Locale: Outside
Re: Re: fire maple model on 07/19/2013 14:33:13 MDT Print View

"But my article does not specify ALL the fine details which are essential to making the stove work."

I see.... Smart you left out the part that keeps it from shooting fire balls at the user.

Daniel Tetreault
(dant8ro) - M
Kickstarter? on 07/20/2013 08:02:09 MDT Print View

Hi Roger,

I've been following your series on BPL for a while now. I'm excited about trying the stove out in the Canadian shield. I do some winter camping and have a lot of camping buddies that are pursuing every last gram.

I know you're still in development, but has Kick Starter crossed your mind? You could set your threshold at enough to cover the cost of all the production level tooling to pump these babies out + whatever other expenses you need per stove to get it done.

I'd be in for a reward level that includes a stove and brings you one level closer to production.

Dan.

Edited by dant8ro on 07/20/2013 08:10:40 MDT.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Kickstarter? on 07/20/2013 16:35:23 MDT Print View

Hi Daniel

> I'm excited about trying the stove out in the Canadian shield. I do some winter camping
You need to email me direct with some details.

> has Kick Starter crossed your mind?
Actually, it never crossed my mind. At present it's a hobby,(albeit a shade odd) but Kickstarter would change that a bit too much for my liking at present. If the stove turns out really popular I wouldn't need the Kickstarter funding; if it isn't then I don't want the hassles of a Kickstarter failure. I have the CNC, and it is a very rugged unit able to handle the workload.

Cheers

James Haithcock
(ke4amp) - M

Locale: Southeastern US
Thanks for the articles on 07/21/2013 06:49:16 MDT Print View

Great articles. If your keeping a list I would be interested in the FMS-300T.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Update on Legs on 07/23/2013 04:40:30 MDT Print View

Hi all

I have spent a couple of days experimenting with a modified design for the legs, and especially for the pivot in the middle. Up till now the stove body and the canister connection had been my main focus. Understandable (imho), but that meant that not enough R&D had been done on the legs - up till now.

A casual observation on my desk while fiddling with a stove gave me an insight into how or why the stove 'wobbles' under load. This led me to see that a huge improvement was possible by adding a simple titanium washer in the right place. After all, adding titanium is always good - right? So I did the experiment, and it works great.

The 0.8 mm thick 'tripod' legs are made of a good alloy (5251 H34) and it seems that the only 1 mm sheet locally available is made from a lesser alloy (5052) which is not much stiffer but is a lot harder to machine cleanly and at speed. For the present I will probably use the good 0.8 mm alloy, as it now gives good stability.

At the same time I will modify the design of the legs themselves just slightly, to create an 'opening tab' at the outer corner. When the legs are all folded together it can be a problem separating them out again. The little tabs at the outer corners are now bent apart so the legs open easily.

As a result I think I will probably withdraw the 'centre support' design from production. If the centre-support legs get at all bent the stove can and will rock. My thanks to several readers who pointed this out to me: you were right. I will upgrade all stoves to this new and better design.

Cheers

Alan Bradley
(ahbradley)
Congratulations on the valve and stove design on 07/23/2013 15:32:31 MDT Print View

Congratulations on the valve and stove design.

Your valve seems very clever: could it become a new standard for commercial stoves?

Could you license it to manufacturers?

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Congratulations on the valve and stove design on 07/23/2013 16:31:24 MDT Print View

Hi Alan

> Your valve seems very clever
Um ... I am going to guess here that you are referring to the shut-off valve in the canister connector, not the one in the stove body.

> could it become a new standard for commercial stoves?
> Could you license it to manufacturers?
It would be nice to think it could be widely adopted, but it adds complexity to the manufacture. Never mind the improved safety and control - that jacks the price up. Would any of the Western stove 'manufacturers' or their Asian factories pay me for the rights?

I may be getting old, but I can't help being a shade cynical. The best ideas for those guys are the pirated ones they don't pay for. Mind you, I am open to any approaches.

Cheers

Greg Mihalik
(greg23) - M

Locale: Colorado
Re: Re: Congratulations on the valve and stove design on 07/23/2013 16:42:05 MDT Print View

Roger,
Not only cynical, but complacent.

You should close with "I'm just waiting for a deep pocket company to rip it off so my lawyers, willing to arbitrate on a contingency basis, can negotiate a fair and equitable deal for all."

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: Congratulations on the valve and stove design on 07/23/2013 22:18:17 MDT Print View

>You should close with "I'm just waiting for a deep pocket company to rip it off so my lawyers,

One does not have to tell them everything in advance...

Mind you, MY idea of 'a fair and equitable deal' might differ slightly from theirs.

Cheers

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Re: Re: Re: Congratulations on the valve and stove design on 07/23/2013 23:25:16 MDT Print View

Presumedly, you have put a defect in the publicly released version that will cause it to explode occasionally.

You'll only release the good version if they give you fair and equitable deal.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: Re: Re: Congratulations on the valve and stove design on 07/24/2013 04:13:23 MDT Print View

> Presumedly, you have put a defect in the publicly released version that will cause it
> to explode occasionally.

Yup. Embedded quantum-spin-based microprocessor chip with an encrypted WiFi link to the BPL membership database. As long as you have a valid membership, the chip stays quiescent and the 2 grams of C4 remains inert. However, if the chip fails to get a valid membership reply about 3 times, it becomes a temperature sensor. When it detects body heat in close proximity ...

Cheers

Alan Bradley
(ahbradley)
Re: Re: Congratulations on the valve and stove design on 07/24/2013 06:42:30 MDT Print View

>>>> Your valve seems very clever
>>Um ... I am going to guess here that you are referring to the shut-off valve in the canister connector, not the one in the stove body.

The shut-off valve is a clever feature for remote stoves with the main control at the burner, but I was mainly referring to the ability to cope with both screw-on and camping gas cartridges. This would seem useful on any commercial stove, even remote ones with conventional heat adjustment at the cylinder end.

Thus the multfit connector would seem worth making available to others/manufacturers: on terms acceptable to yourself.

I have decided remote stoves are better: and have merged my can-top with a brunton stand, however, I still like meths :-).

Edited by ahbradley on 07/24/2013 06:52:31 MDT.

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
The Evolution of a Winter Stove - Part 3 on 07/24/2013 06:57:59 MDT Print View

I see that you have upgraded the stands. Great News! I was sort of wondering about that. Stainless is heavier but not really that much stiffer (unless well tempered.) Stoves like the Simmerlight/Windpro didn't seem all that floppy. But, I am guessing this add-on bit will require occasional adjustment, and/or loctite. Lighter is usually better when well designed.

I was thinking about the brass nut locking the FM-300T burner on. A small seat could be milled into the body letting you remove it. A fairly precise distance between the jet, air inlet holes and seat could be maintained that way and it might save a few grams of brass. This might require some clearance for the bottom of the threading on the burner body/mixing chamber though.

Well thought out!

Stuart R
(Scunnered) - F

Locale: Scotland
Re: The Evolution of a Winter Stove - Part 3 on 07/24/2013 15:07:09 MDT Print View

Very nice work Roger, I particularly like the versatility of the canister connector. Availability of canisters in small villages in the remoter parts of Europe is a bit of a lottery.

Brian Jones
(jonesbr) - MLife
Conversion to a hanging system? on 07/25/2013 19:21:03 MDT Print View

Great work, Roger!

Your stove looks like just about everything I've looked for in a remote, inverted canister stove.

The one place where a more traditional upright canister stove would seem to have an advantage is in its ability to convert into a hanging system for use inside a tent.

Looking at your design:

1) Is the fuel tube long enough to reach a canister hanging just below the pot legs?
2) would it be possible to add notches or something similar to the underside of the pot legs such that they could retain the rolled lip of an inverted canister? (A wire "basket" anchored off the legs would likely be simpler, if less elegant. Or maybe a rubber/silicone ring that could slide over the inverted canister with small holes that would allow clips to connect it to the legs...)
3) If you tried to suspend the setup by running your suspension wires to the outermost cutouts on the legs (likely using a spreader bar or two on the wires), would it be stable enough if you had the weight of canister hanging below it? (Worst case would obviously be a full pot and empty canister, and I suspect that it might be too unstable.)

This may be a level of flexibility beyond your interest, but it intrigued me, so I thought I'd ask.

Thanks!

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: The Evolution of a Winter Stove - Part 3 on 07/25/2013 22:22:45 MDT Print View

Hi James

> I am guessing this add-on bit will require occasional adjustment, and/or loctite.
In theory, no.
The nut which clamps all this together is done up tight against the end of the leg pivot. This means the nut should never loosen, despite the legs spinning wildly. There are low-friction brass shim washers to cut the friction and prevent galling, so there is negligible torque on the nut anyhow. The stainless steel grub screw which holds the nut is jammed in place rather tightly - it does its own thread forming in fact.

> the brass nut locking the FM-300T burner on.
Yes, I wondered about this too. But the weight of the nut is actually very low, and it serves TWO purposes. First of all it locks the burner onto the stove body so it does not accidentally unscrew and fall off. In addition, it allows me to align the pot supports on the burner with the heat exchanger coming up from the stove body. In theory I could adjust the start angle of the thread to do this by itself, but if they change the start angle on the burner column with respect to the pot supports during manufacture I would be in trouble. In practice, I don't think that angle is even controlled during manufacture.

The change in position of the air holes with respect to the face of the jet would be at the most slightly under 0.2 mm for the worst case alignment. The distance between the air holes and the jet is around 7 mm. Methinks I will not worry.

Cheers

Michael Driscoll
(Hillhikerz) - M

Locale: Monterey Bay
Roger stove ? on 07/26/2013 10:54:59 MDT Print View

Did not see this in the thread so far but was wondering if an upside down Coleman canister with adapter will work with this stove... Or is that just crazy thinking...

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Re: The Evolution of a Winter Stove - Part 3 on 07/26/2013 12:25:35 MDT Print View

"The nut which clamps all this together is done up tight against the end of the leg pivot. This means the nut should never loosen, despite the legs spinning wildly. There are low-friction brass shim washers to cut the friction and prevent galling, so there is negligible torque on the nut anyhow. The stainless steel grub screw which holds the nut is jammed in place rather tightly - it does its own thread forming in fact."

Yeah, I can see where that would work. It occured to me that the Simmerlite pot stand was actually connected at the top, too. This adds a considerable stiffness, overall, to the stove. I am sure you have it well in hand.

Yeah, the alignment could get to be a problem around the heat transfer bar. Not as clean as I thought. Thanks for pointing that out. How do you align the Fm-116 burners? I am guessing the upper nut on the FM-300 is adjustable, also.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Roger stove ? on 07/26/2013 16:19:11 MDT Print View

> wondering if an upside down Coleman canister with adapter will work with this stove
There are two sorts of Coleman canisters: screw-thread and Powermax. BOTH work without any adapter being needed.

The hair-spray style with a spray jet on top does not work, but they only have butane in them - not suited to winter use.

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: The Evolution of a Winter Stove - Part 3 on 07/26/2013 16:22:40 MDT Print View

> How do you align the Fm-116 burners?
I only have a few of them, so I took some care with the CNC and the start angle for the thread on the stove body. A very thin shim can also be used.

> I am guessing the upper nut on the FM-300 is adjustable, also.
It is usually done up tight. It holds the pot supports in place. Best to leave it done up tight. I guess you could spin it off, machine a gram or two off it, and replace it.

Cheers

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Re: Roger stove ? on 07/26/2013 16:29:32 MDT Print View

"The hair-spray style with a spray jet on top does not work, but they only have butane in them - not suited to winter use."

But, the boiling point is 32 F or whatever. If you put it in your pocket you can warm it up and use below 32 F. With your stove you don't get evaporative cooling so you should be able to use it as long as contents are above 32 F.

If a canister is 2 ounces, fuel 2.75 ounces, your stove is 3.5 ounces - total 8.25 ounces - enough fuel to boil maybe 11 pints. That could be a good option for many trips.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: Roger stove ? on 07/26/2013 21:16:51 MDT Print View

> the boiling point is 32 F or whatever. If you put it in your pocket you can warm it
> up and use below 32 F. With your stove you don't get evaporative cooling so you
> should be able to use it as long as contents are above 32 F.
True, and if it's a Ronson lighter with iso-butane you could be on a good thing.

You can use n-butane (which boils at 0 C) at sub-freezing temperatures IF you use all the tricks, but it's going to be more tricky. It's not something I would recommend to a novice, but an experienced winter walker could do it OK.

Cheers

Robert H
(roberth)
Re: Pot support on 07/27/2013 05:07:02 MDT Print View

Hey Roger,

With the new design tripod design is the plywood board and micro-stakes (what are these and where do I get them by the way?) still needed?

Cheers.

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Re: Re: Roger stove ? on 07/27/2013 08:09:34 MDT Print View

Jerry, if it is not at or above the boiling point, then little pressure is generated in the canister.

I hadn't really thought about evaporative cooling, but you are right. Very little.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Re: Re: Re: Roger stove ? on 07/27/2013 08:26:21 MDT Print View

"I hadn't really thought about evaporative cooling, but you are right."

You obviously haven't used upright canister in cold weather : ) It always gets covered with frost. I bet it gets 10 degree F colder than ambient or even more.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Pot support on 07/27/2013 16:14:35 MDT Print View

Hi Robert

> With the new design tripod design is the plywood board and micro-stakes still needed?
The plywood base is nice to have when camping on soil or rock. It is essential when camping on snow.
The micro-stakes are useful, but not essential.

> (what are these and where do I get them by the way?)
Plywood base - that's an MYOG thing. Artistic licence allowed. I recommend ply rather than any sort of craftwood: the latter goes soggy rather quickly. Metal is a bit slippery.

Micro-stakes - hum, yes. I use Ti welding wire. Maybe you can find a welder who can give you one, or maybe you could use some stainless steel MIG wire. Or you could use high tensile bicycle spokes from a bike shop - you can even get Ti ones. The stakes don't have to be very long - under 10 cm.

I am sure creative minds will come up with all sorts of variants in time. Please let us know about them!

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: Re: Re: Roger stove ? on 07/27/2013 16:15:41 MDT Print View

> I bet it gets 10 degree F colder than ambient or even more.
10 C or more.

Cheers

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Re: Re: Re: Re: Roger stove ? on 07/27/2013 18:11:51 MDT Print View

You obviously haven't used upright canister in cold weather : ) It always gets covered with frost. I bet it gets 10 degree F colder than ambient or even more.

For an upright I can see that. I thought the discussion was for Roger's stove.

No, I havent used a canister much below 40F, if that. I usually use WG on longer trips or alcohol for short ones.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: Roger stove ? on 07/28/2013 00:50:47 MDT Print View

> With your stove you don't get evaporative cooling so you should be able to use it as
> long as contents are above 32 F.
Entirely correct.
But young novices do some strange things...

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Update on Legs, part 2 on 07/31/2013 04:41:12 MDT Print View

Update 1

I was sitting there in the evening playing with a stove on my workbench, thinking vaguely about the leg stability problem, when I actually SAW what I was looking at. That is, I actually looked closely at what the legs were really doing - and it was not at all what I had been assuming. I went to bed thinking about what I had seen, and in the morning I shot out to the workshop to make some replacement parts.

To cut a long story very short, the replacement parts made the standard tripod legs much stronger and more stable. The whole idea of a centre support is fine, but if the tripod is stable enough it is not needed for a little stove like this.

A longer story is that I had been slowly upgrading the legs from a quite different titanium version which combined the tripod with the pot supports. There are some photos of these in Part 2. But I had not gone the whole distance.

5396 Winter Stoves with updated legs

The new legs look like this. Well, OK, you may not even see any difference at first, except that the outer end of each leg now has a stylish tilt to it. The critical difference is at the pivot, where the rather small 14 mm shim washers which I had been using have all been replaced with much larger 22 mm Ti washers and brass shim washers. This has made a huge difference. (Anyone want a large supply of brass shim washers 14 mm diameter?)

There is one other small change in the leg profile: the small tab at the outer corner. This merits an explanation too. I machine each set of three legs together. That's a bit slow, but it makes for a much nicer set when they are folded together. The trouble was when the legs were all folded together they were packed really close together, and it was hard to separate them out. You could be sitting there at -20 C trying to set the stove up with gloves on and be cursing me for making the legs so hard to open. Not good enough.

The tabs on the two outside legs in the set are given a slight bend outwards, while the middle leg has a straight tab. Now it is easy to separate the legs. I should have forseen this as well, but I didn't.

The older tripod legs have been withdrawn and scrapped. The centre-support legs have also been withdrawn, although if anyone really wants them I can supply them from the existing stock. All stoves have been upgraded to the new improved legs.

Cheers

Franco Darioli
(Franco) - M

Locale: Melbourne
The Evolution of a Winter Stove - Part 3 on 08/01/2013 15:54:31 MDT Print View

The 116T RC has just arrived at my place.
Unfortunately I am almost packed up (moving house) so no tests for about 1 week.
As first impression feels incredibly light (90g on my =/-5g scale) for what it is.
My other two stoves of this type are almost twice and over twice that weight..
It holds a heavy pot with 2 liters of water and that is more than I need.
There is a bit of flex when you put that weight on but still sits nicely as you see in the photo.
Must remember (same as with my Kovea) to check that the arms are correctly open.
RC 116T 1
RC 116T 2

Edited by Franco on 09/30/2013 19:46:38 MDT.

Paul McLaughlin
(paul) - MLife
A little test if you get the chance on 08/04/2013 15:15:20 MDT Print View

Roger - testing published here on BPL in the past showed remote canister stoves having lower fuel efficiency on average than top mounts. Now that you have a remote with the identical burner head as a top mount, I'd love to see whether there is a difference in fuel efficiency between the two configurations when the burner head is identical. If you have the time.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: A little test if you get the chance on 08/04/2013 16:19:15 MDT Print View

Hi Paul

> testing published here on BPL in the past showed remote canister stoves having lower
> fuel efficiency on average than top mounts.
Um - got a URL for that? I don't remember publishing that sort of data myself. Could be failing memory of course.

On the other hand, people using a remote are often starting with colder water, and may run the stove a bit higher in power because of the cold. Both of those will certainly affect the fuel used.

I'm prepared to stick my neck out and say that there should be no difference in fuel efficiency provided that all other factors are equal. After all, how far away the canister is should not really affect the result - should it?

Cheers

Paul McLaughlin
(paul) - MLife
Re: Re: A little test if you get the chance on 08/04/2013 18:19:26 MDT Print View

http://www.backpackinglight.com/cgi-bin/backpackinglight/canister_stove_efficiency_p2.html

Scroll down to "Analysis" and "Uprights vs. Remotes"

So here's our chance to see if it's all about burner size/design or if there is something more mysterious going on. And for even more fun, you could run the remote version in canister inverted and canister upright modes and see if that makes a difference.

M B
(livingontheroad) - M
remote on 08/04/2013 22:00:43 MDT Print View

technically, the liquid feed could be sucking heat from the burner zone to vaporize the liquid, where a normal cannister feed can be using more ambient air heat. Or maybe not.

but the heat of vaporization has to come from somewhere, all depends on how heat is retained by the windscreen.

When somewhere around 1/2 of the heat of combustion is lost to atm anyway instead of going into the water, its easy to either creaste false small differences in efficiencies, or hide them.

Edited by livingontheroad on 08/04/2013 22:01:49 MDT.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: remote on 08/04/2013 22:11:15 MDT Print View

Butane - heat of evaporation 320 kJ/kg, heat of combustion 45,000 kJ/kg

takes less than 1% of combustion heat to evaporate

shouldn't be significant

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: A little test if you get the chance on 08/05/2013 04:17:34 MDT Print View

Hi Paul

Um and Oh. My own series of articles. Oh Dear. :-)

OK, part of the problem there was that we were comparing apples, oranges and the odd bunch of grapes. Some of the remotes had rather large burners which were less efficient for a given pot diameter than the smaller uprights. Some of the remote burners were just a bit strange too. I am going to blame most of the variation between the two classes on flame or burner diameter, as I noted in that article:

What is surprising is that the Remotes are generally less efficient (blue diamonds) than the Uprights. We believe that part of the reason for this is that the average flame diameter for the Remotes is larger than for the Uprights, and the flames are therefore closer to the edge of the pot. When the flames curl up around the edge of the pot, you know the efficiency is going to fall, as heat is being wasted.

However, with a remote canister stove based on the FMS116T or FMS-300T (ie mine), we could expect that the performance would be the same since the burner is the same. Perhaps one day, when I have built all these stoves for beta testing, I will get the time to run this experiment and report on it.

Cheers

M B
(livingontheroad) - M
significant on 08/05/2013 08:40:01 MDT Print View

totally agree it shouldnt be significant.

But as I said, when you are losing half your heat to the environment anyway, detecting small efficiency changes only works if you can keep other losses constant.

Or better, completely optimized for each individual stove. Without this, any data has a chance of being invalid.

Michael Driscoll
(Hillhikerz) - M

Locale: Monterey Bay
The Evolution of a Winter Stove - sound on 08/28/2013 15:50:08 MDT Print View

remote canister stove based on the FMS116T or FMS-300T of the 2 models you are selling which would be the quieter running stove... could not remember if it was mentioned in the series or not...

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: The Evolution of a Winter Stove - sound on 09/13/2013 17:35:03 MDT Print View

> FMS116T or FMS-300T of the 2 models you are selling which would be the quieter
Oh, very definitely, the FMS-116T version.
I have one or two of those left still.

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Update on beta-test stoves - why the delay on 09/13/2013 17:36:38 MDT Print View

Hi all

I have to apologise for a bit of a delay in getting the beta-test stoves
built and shipped. Such delays are why I did not want to accept any money
earlier: they happen.

First, the X axis on my CNC machine started to jam. I knew what was
causing this: dust from machining Corain plastic had got past the brush
seal into the oil in the ball-nut. This turned the oil into very thick
grease and the little balls were jamming in their grooves. never again
will I machine any Corian plastic! Fixing this meant stripping the X axis
drive system down, cleaning the double ball-nut out, and rebuilding it.
That includes actually disassembling the double ball-nut itself, cleaning
it, and then putting all the balls back in without losing any. This was
not easy - the machine weighs 240kg (530 pounds) and had to be jacked up
for access underneath, but it was done. I lost a good part of a week here.

Then we had problems with the greywater disposal system we use on the
farm. (No sewer connection on farms.) The washing machine stopped working
properly. You don't argue when this sort of thing happens! Fixing this
took a good part of a week too. Lots of spade work. All OK now.

Then, just as I was getting back to the workshop, I went down with this
year's flu. It was a good dose (if 'good' is the right word): I was out
for about 3 weeks and am only just now starting to get back into action.
Imagine: a tiny 0.01 micron virus able to flatten an adult human being.

Anyhow, I will be back in the workshop pretty soon, working on the final
parts needed to be able to start shipping the FMS-300T version of the
stove. It will take a couple of weeks to have some ready. Then I will
contact all of you who have expressed an interest (by direct email).

Cheers

Michael Gillenwater
(mwgillenwater) - M

Locale: Seattle area
Re: Update on beta-test stoves - why the delay on 09/16/2013 18:10:12 MDT Print View

Glad you are feeling better. And no apologies necessary. Life if full of the unexpected.

Oliver Nissen
(olivernissen) - MLife

Locale: Yorkshire Dales
Same sentiments, no apologies necessary... on 09/30/2013 14:08:51 MDT Print View

Roger: I'm glad to hear you weren't flattened under 240kgs of CNC machine, but sorry to hear you were laid flat by a 0.01 microns wide, three weeks long flu virus... And for all your other set backs too.

I received your email, but just wanted to bring to your attention that you'd left your dollars ambiguous! It's safer to assume you're referring to US dollars (we're not going to short change you that way), as opposed to the more economical Australian variety.

My Paypal payment sent! Thanks

Edited by olivernissen on 09/30/2013 15:33:06 MDT.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
At last - production is happening on 10/03/2013 03:06:02 MDT Print View

After many weeks of promises, promises, we really do have production at an advanced stage. Andf the 3+ weeks of flu is past.

5483 Lots of canister connectors
Here we have a stack of canister connectors with cam valves in place. The next step is to connect up a lot of hoses - one is shown at the bottom.

The green-handled screw-driver at the top is an aid for the aged ... :-) Actually, it was getting painful putting the self-tapping screws into the acetal plastic for the retainer plates because the first insertion is a serious thread-forming process, and the handle of the silver screwdriver was really thin. The fat green handle makes that easy.

All the Nalge bottles at the top - bottles of bits to go into the stove. Amazing how many separate parts are involved.

5481 a range of stove parts
A range of parts. Untested stoves with burners at the left, then untested stoves without burners, a stove body with the new tripod legs, a fan of tripod legs, a handful of canister connectors with hoses, and finally at the right a handful of hoses.

The hoses do not have the filling cord inside yet, and they don't have the essential little internal heat exchanger rods either. They go in when the hose is connected to the stove body. Tomorrow is another day.

The final stage will be testing: pressure testing for leaks, flow testing for the whole system, and then a burn test for each stove to make sure the darn things work. So far I have caught one hose which was mostly blocked for some reason, and one stove which did not burn correctly. The latter had a foreign jet by mistake, and the fuel/air ratio was all wrong.

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Wednesday 9-Oct on 10/09/2013 00:00:44 MDT Print View

The first batch of stoves has been assembled.
They have all been pressure-tested for leaks and for flow.
They are now being individually burn-tested.
Next stop, package them all up and down to the post office.

Cheers
Edited to fix date

Edited by rcaffin on 10/09/2013 14:28:15 MDT.

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Wednesday 6-Oct ?? on 10/09/2013 00:15:12 MDT Print View

What calendar are you looking at?

--B.G.--

Franco Darioli
(Franco) - M

Locale: Melbourne
The Evolution of a Winter Stove - Part 3 on 10/09/2013 00:50:16 MDT Print View

2021.
I am glad I put my order in early.

Rick M
(rmjapan) - F

Locale: Tokyo, Japan
Re: Re: Wednesday 6-Oct ?? on 10/09/2013 00:50:18 MDT Print View

What the heck is this? Roger is now making/selling a winter remote canister stove? Is it a limited beta or a full on production? What are the details/specs? Do we send our stoves to be modified? How much and where do I sign up?

Neil Johnstone
(nsjohnstone) - MLife
Wednesday 6th October on 10/09/2013 04:12:28 MDT Print View

Easily explained.
He is in Australia, so is upside down.
A 6 upside down is a 9......................

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Re: Wednesday 6-Oct ?? on 10/09/2013 04:48:39 MDT Print View

October 6??? OK. You design a stove that is better than anything else. You repair CNC millers. You fiddle with things around the farm. But, you still do that retired thing and loose track of the date. Ahh, well...We know what you mean...well, sometimes anyway. That bug must've really knocked hell out of you. Nope, it must have been all that diggin'.

Anyway, I didn't get a confirmation from you, . I ass-u-me you got the payment. Thanks Roger!

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Wednesday 6th October on 10/09/2013 08:49:16 MDT Print View

Neil, you beat me to it...

Australian calendar is upside down

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: Wednesday 6-Oct ?? on 10/09/2013 14:34:55 MDT Print View

Hi Jim

> I didn't get a confirmation from you, . I ass-u-me you got the payment.
That's the good thing about Paypal: you get a FULL record of transactions.
And yes, I check Paypal every day and record all payments on my machine too. Yours was recorded.

The date - a simple typo. But it seems to have created lots of postings! :-)

All stoves in this batch have been pressure tested for leaks (100% pass rate) and for flow rate (100% pass rate). They are now being burn-tested for correct fuel/air mix and power.

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: Wednesday 6-Oct ?? on 10/09/2013 14:37:12 MDT Print View

Hi Rick

> What are the details/specs?
Well, if you read the 3 articles to which this Forum thread is attached, you will find all the gory details.

Cheers

Rick M
(rmjapan) - F

Locale: Tokyo, Japan
Re: Re: Re: Re: Wednesday 6-Oct ?? on 10/09/2013 15:12:52 MDT Print View

Roger, don't suppose there is a Cliff's Notes version of the info for those of us not privy to the BPL secret handshake?

Erik G
(fox212) - F

Locale: THE Bay Area :)
Re: Cliff Notes on 10/09/2013 15:35:36 MDT Print View

+1 to Rick M's request for a quick summary of the specs and if/how we could order one. I really want to get my hands on one of these stoves, but I really don't want to have to pay for an article or three just to see how to get it. It's the articles or the stove for this guy! :)

Edited by fox212 on 10/09/2013 15:36:29 MDT.

Michael Gillenwater
(mwgillenwater) - M

Locale: Seattle area
Re: Re: Cliff Notes on 10/09/2013 15:39:29 MDT Print View

Not to set off a firestorm of my own, but it is only $25 to be a member of BPL and get access to everything.

Peter (Taking a break)
(prse) - MLife

Locale: Denmark
Support on 10/09/2013 16:08:02 MDT Print View

This would seem like a good time to support BPL, so Roger can continue his awesome work/articles that we have all benefited so much from...

Erik G
(fox212) - F

Locale: THE Bay Area :)
Re: Cliff Notes and Support on 10/09/2013 16:28:37 MDT Print View

Thank you for the kind reminders and advice on how to spend my money. ;) I'd much rather support the development of the stove by - you guessed it - buying a stove! I really don't want to start a debate about the relative value of a dollar or 25 and trash this thread. If the requested info is members only, then so be it. If not, somebody spill the beans! :)

Edited by fox212 on 10/09/2013 16:31:53 MDT.

Rick M
(rmjapan) - F

Locale: Tokyo, Japan
Re: Re: Cliff Notes and Support on 10/09/2013 16:56:45 MDT Print View

Yes, and let's not forget the Kovea Spider can be had on eBay for only US$50 shipped. But from what I've gathered in Franco's post above, his 116t RC stove weighs 90g and may offer more power output control with the valve at the stove instead of the canister.

Anyway, I already have a 116t stove and I can still get high propane content Winter gas here in Japan. Wrapping some copper wire around the canister and leaving the tip in the flame for a makeshift canister power booster allowed me to have good burns in -10C temps.

Peter (Taking a break)
(prse) - MLife

Locale: Denmark
No worries on 10/09/2013 17:15:51 MDT Print View

I'll be so kind and suggest you get a membership AND the stove.

Yours truly! :-)

Ken Thompson
(kthompson) - MLife
Re: Support on 10/09/2013 18:26:50 MDT Print View

Roger volunteers all him time and effort here at BPL. Throwing money at BPL unfortunately will have no impact on Roger. If BPL was to cease Roger would have more free time to get stoves done. Catch 22.

Nice stove Roger.

Thanks for everything!

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Re: Cliff Notes on 10/09/2013 19:51:32 MDT Print View

Well, to be fair to Roger, BPL and all readers, specs are simply not available.
It sortof depends on how you plan on using the stove, ie, wind/heat screen, pot size, snow melting or not, boil and dump cooking vs real cooking, temp of water, temp of air, and a lot of other factors that are debated in several hundred threads on stoves here. That said, I am looking at getting about 14L boiled out of a single 100g canister. This is slightly less efficient than what I get out of my SVEA. (I get about 14L out of 4.2floz of WG or adjusting for density to weight about 14L/3.276oz or 14L/91.728g.) But the weight of the outfit is finally significantly less. Every other set-up results in carrying MORE weight over my average trip length of about a week.
Roger's stove:
3.3oz/90g (actually it might weigh a bit less, but I have not received it yet to weigh it.)
100g Jet Boil canister + 100g can (200g total or 7.143oz total)
Pot: 3.25oz/91g
Cup: 1.625oz/45.5g
Wind/Heat screen: 1.75oz/48g
TOTAL: 17.068oz/477.904g for about 5 days at my usage (2 liters per day plus simmering.)

SVEA: 17oz
Cup: 2.625oz (cover for transporting stove)
4oz of fuel + bottle: 5oz total or 140g (for 6 days out at my usage)
Pot: 3.25oz/91g
Wind/Heat screen: 1.75oz/48g
Total: 29.625oz/ or 829.5g for 5 days at my usage(actual tested usage.)

Both are UL setups, and NOT a typical SUL setup. I do a lot of real cooking. Soups, stews, rice, etc. So, for a week out,I would carry about 24oz with Rogers stove. I would add another 4oz in fuel for the SVEA at about 34oz. I WILL go for that at about a 10oz savings.

I would strongly suggest buying a membership.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Re: Re: Cliff Notes on 10/09/2013 20:16:34 MDT Print View

Roger's stove has the canister remote so you can turn the canister upside down so you can use it in colder temperatures. Regular canister stove is good down to maybe 25 F. Inverted should be good down to boiling point which is maybe 12 F. Also, the burner is lower in the air so less susceptible to wind.

Roger's articles are worth the price. He addresses a number of problems and goes into infinite detail.

14 L boiled out of 100 g canister?

I use 1 oz per day. there are 3.5 oz in 100 g. I boil 64 ounces of water = 2 L. That's 7 L boiled from a 100 g canister. Hmmm - where's my factor of 2 error?

Rick M
(rmjapan) - F

Locale: Tokyo, Japan
Re: Re: Re: Re: Cliff Notes on 10/09/2013 20:42:31 MDT Print View

"Roger's articles are worth the price. He addresses a number of problems and goes into infinite detail"

I'm sure they would be IF that was the kind of detail that I wanted to know. But its just a stove. I really don't care about the minutiae of its operation and manufacturing in the same way I don't bother to care how my TV or fridge works or what's inside them. It just needs to work safely and be a better solution than I use now.

I was just surprised to read this stove mod was some new cottage business Roger was into. Obviously its still in beta or perhaps a BPL members perk which would explain the membership cat-n-mouse attitude.

But I can be patient. If its good, reviews will start popping up in other forums. And if the intent is to make a commercially viable product, then it will have to sell outside the BPL membership eventually. I suspect maybe even Kovea or Fire Maple will offer it too! ;-)

Edited by rmjapan on 10/09/2013 21:00:24 MDT.

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Re: Re: Re: Cliff Notes on 10/09/2013 22:09:25 MDT Print View

Jerry, 8g/.8L was quoted as the lowest Roger gets at medium heat.

I was reducing his numbers a bit due to three things:
** a cone type setup(Roger doesn't use one)
** a heat exchanger pot(about 10% more efficient.)
** using LOW heat (Roger was using medium heat.)

I figure about 2g/L for all three items, roughly. I was hoping for 5-6g/Liter or .2oz/L but I don't think that will happen.

I get about 9g/L out of my SVEA with the same set up. I know that canister gas has a higher heat value than WG initially(before adding in the weight of the can,) but I am ignoring that. I am also ignoring the gram or two difference that is wasted during priming (I actually added that in when I measuered the SVEA because I used a midi-pump to start it, but the canster stove wouldn't require any priming.)

Anyway, max efficiency should be about 10-12 minutes to boil a liter with about 8g of isobutane/propane. I am sure it will not do WORSE than my SVEA. I get roughly 3-4 liters per ounce(average 9g/L.) If I am cooking meals, I figure two liters per day including 2 primings and simmering for about 15-20 minutes on one ounce of fuel. Hey, ha...I eat like two people when I am out...

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Re: Re: Re: Re: Cliff Notes on 10/09/2013 22:59:44 MDT Print View

Looking some more at Roger's articles, he talked about 9 g to boil 1 liter for Jetboil, 11.5 g for conventional upright, close to what you're saying. I assume his stove will be closer to 11.5 g since he has no heat exchanger. I bet some measurements will be posted at some point...

Mark Fowler
(KramRelwof) - MLife

Locale: Namadgi
Why 2 x 100g canisters on 10/10/2013 00:07:58 MDT Print View

James - Why carry 2 x 100g canisters rather than a single 230g canister? 2 x 90g = 180g canister weight versus 135g. The weight saving more than covers the extra 30 grams of gas and extends your range by a day.

Edited by KramRelwof on 10/10/2013 00:09:18 MDT.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: Re: Re: Cliff Notes on 10/10/2013 01:27:58 MDT Print View

> I'm sure they would be IF that was the kind of detail that I wanted to know. But its
> just a stove. I really don't care about the minutiae of its operation and manufacturing

Heresy and blasphemy!!! :-)

> If its good, reviews will start popping up in other forums.

Only if I decide to sell it outside the BPL environment. That is not a given. This manufacturing thing is hard work!
Licensing to another manufacturer? Maybe one day.

Cheers

Edited by rcaffin on 10/10/2013 01:28:56 MDT.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Second Shipping on 10/10/2013 01:45:22 MDT Print View

Hi all

I have previously shipped 8 of the stoves with the FMS-116T burner some time ago.

Shipping 1 stoves in boxes
I am happy to report that the current batch of ~30 stoves have all been through their final burn test and been packed up into boxes. The back block is double thickness (ie 2 layers) and is for USA. The middle layer goes to Europe - we have quite a few European readers.
The front small group stays within Australia.

What boggles me is that I can buy 'little things' from ebay from Hong Kong for $2, and that includes packing and postage. How they do this is beyond me! The cardboard boxes cost nearly $1.40 each, plus there's bubble wrap and packaging tape. And you KNOW what the postage is like. (Does the Chinese gov't subsidise exports this way? Hum ...)

Anyhow, most of the orders I have received so far are in this batch. A few of the latest ones missed out because I ran out of stove bodies. Sorry about that. But yes, I have all the other bits, so it's back to the mill for more stove bodies tomorrow.

Manufacturing & production is SO different from scientific research! My respect for the manufacturing industry goes up.

Cheers

Edited by rcaffin on 10/10/2013 15:15:35 MDT.

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Second Shipping on 10/10/2013 04:36:16 MDT Print View

Roger,
I don't/can't do much winter camping any, so I can wait. Send mine along when you get the second batch done.
Thanks!

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Why 2 x 100g canisters on 10/10/2013 04:53:58 MDT Print View

Mark,
I have found that cannisters are generally unreliable. I have lost 2 in the one year that I tried them (back when the Coleman F1 was newly released.) Both had problems with the Lindal valves and emptied in my pack after using them. One was the older Coleman, the other was a Snow Peak. I have not heard of this happening in a couple years, though...not since they fixed the valves to be standard for all stoves. I hope it was a tollerance problem, hence fixed. But, I'll stick with two 4oz cans for the next year, even if they are heavier.

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Re: Re: Re: Re: Re: Cliff Notes on 10/10/2013 06:13:11 MDT Print View

"Looking some more at Roger's articles, he talked about 9 g to boil 1 liter for Jetboil, 11.5 g for conventional upright, close to what you're saying. I assume his stove will be closer to 11.5 g since he has no heat exchanger. I bet some measurements will be posted at some point..."

Yeah, well, heat exchangers are not a magic bullet. While I made several of the things, and still use one, their action is not well understood by most. Basically, they only extend the surface area (the heating surface) of a pot. Example, the ones I made were about 17% larger in surface area for a 5.25" grease pot pan. I get about 21.65 sqin of heatable pot bottom out of a standard grease pot. After adding the heat exchanger ridges, I get about 25.33 sqin.

But I only get about 15% faster heating given the same flame on both pots. Reducing the flame shows only a 10% decrease in heating times. Reducing the flame again shows only a 7% decrease in heating times. On very low it only shows about 5% (near the limit of my tests) decrease. With a tiny flame, I was getting 20-25 minute boils but didn't show any real difference (+-15 secs) over 5 runs. It starts to depend more on heat losses than heat absorbed.

Soo, what is happening here, is that the more efficient you set the flame height (very low is the best for fuel efficiency) the less well they work. Or you can think of the simplified corallory as they only work with excess heat. (Not quite true, but close enough for camping.)

JetBoils are not as efficient as alcohol stoves. Why? With a well placed heat screen, the sides of the pot as well as the bottom are used to heat water. A typical alcohol stove set-up always includes a good heat screen at least 50% up the sides. This is largly offset by the good heat exchanger JetBoil uses. It is about doubling the bottom heating surface area. But, putting these two things together, means the heat exchanger efficiency falls off as fuel efficiency goes up. Sort of a cache 22. You don't save enough by going to low heat to make it worth it since the heat exchanger efficiency drops off quickly, too...looks to be a curve.

Basically, I am planning on using the cannister stove as a heat source in a typical alcohol stove set-up. I am hoping to reduce the ammount of fuel required to boil 40F(4.5C) water to boiling (210F or ~99C) with about 5-6g of fuel under ideal conditions in a lab. This will mean a 20% increase in the field, or about 6-7g/L.
But, anything less than 9g/L would be acceptable, given the weight for two weeks at my usage. It MUST do better than my SVEA, or I will just drop it.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Second Shipping on 10/10/2013 07:52:22 MDT Print View

"Does the Chinese gov't subsidise exports this way? Hum ..."

yeah

I've recently bought several things for less than $10 from China via amazon.com - portable MP3 charger, automobile cigarette lighter MP3 charger, and a wind speed meter. How do they do it?

And a couple scales with 0.1 g resolution. The first one broke. It's so cheap I don't care it'll probably break sometime.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Cliff Notes on 10/10/2013 08:48:20 MDT Print View

That makes sense about heat exchanger - low flame will stay next to pot without heat exchanger so it makes less difference.

One thing is, if you go slowly, there will be more time to disipate heat so efficiency will go down. I wonder how much of a factor that is.

I made heat exchanger - accordian folded aluminum over the outside of the pot with channels about 1/4 inch high for the flame residual to flow through. 13.5 g/L w/o heat exchanger, 11.4 g/L with, 15% decrease. The 15% decrease is about the same as you said.

But my 13.5 g/L is a little larger than the number Roger measured 11.6 g/L. I used a Pocket Rocket which might be worse than average and I did it outside in the wilderness rather than a lab setting which might explain this?

If you could get less than 9 g/L that would be pretty good. Report back your results!

James Klein
(jnklein21) - M

Locale: Southeast
Re: Re: Re: Re: Re: Re: Re: Cliff Notes on 10/10/2013 09:30:59 MDT Print View

James, care to show the details of your grease pot HTX ridges?

"Soo, what is happening here, is that the more efficient you set the flame height (very low is the best for fuel efficiency) the less well they work"
I agree - there are diminishing returns as burn rate decreases. Though it is still nice to have the extra margin for when you really want to warm water fast. I have trouble getting HTX pots to pay for themselves (in fuel savings) over what I'd use otherwise b/c they are all heavier gauge metal and tend to be narrow.

"JetBoils are not as efficient as alcohol stoves".
I can certainly boil water more efficiently in a HTX and cone setup with remote canister stove than with alcohol (1/3 less fuel require) (with water heatup rate, pot/cone setup, etc equal). I also see improvement by adding a cone the the HTX pot setup with cannister stove if heating fast enough, though, unless wind is involved in would lake a lot of boils for the windscreen to pay for itself in fuel savings.

"5-6g of fuel under ideal conditions in a lab. This will mean a 20% increase in the field, or about 6-7g/L".
It would take about ~400kJ to raise 1L of water 95C. To get 400kJ youd need about 9g of butane/iso/propane (@100% heat transfer efficiency). I could do the above with ~12grams fuel.

James Klein
(jnklein21) - M

Locale: Southeast
Re: Re: Re: Re: Re: Cliff Notes on 10/10/2013 09:47:14 MDT Print View

Rick, I think you've gotten the details you were after but if not:

Roger made a remote canister setup (capable of inverted "winter" use). His can use either the Fire Maple 113t or 300t burners.
[EDIT: FMS-116T or FMS-300T - RNC]

-Finished weight is 80-90 grams - he quotes 80s but has since change the legs a little. This is about half the weight of any comparable off the shelf stove.
-It has a needle valve at the stove and an on/off valve on the cannister end.
-Small flexible fuel line
-Canister connector can handle typical canistor, powermax or campinggas.
-He has offered it for $125USD to bpl members in a limited production run. And, I think, has no specific plans to go commercial on this stove.

Edited by rcaffin on 10/10/2013 15:13:16 MDT.

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Re: Re: Re: Re: Re: Re: Re: Cliff Notes on 10/10/2013 13:00:41 MDT Print View

"James, care to show the details of your grease pot HTX ridges? "
Well, it really doesn't belong here, but sure.
Hmmm, I don't have a current version pic, but I have a set of development pics. Here is one that shows the genesis.
Some pots

The current version has 5 ridges at about 3/16 depth. The old three ridged version has about the same depth, but only helps about 11% overall. Sorry...I thought I had one.

As far as fuel usage goes, I was guessing I was bumping into max efficiency. I don't really care, since even flowing water is usually about 34-35F even if it has ice in it. 12g is a LOT of fuel, though. I may have to hope for 50F water when I am out just to hit 9g.

Rick M
(rmjapan) - F

Locale: Tokyo, Japan
Re: Cliff Notes on 10/10/2013 16:09:17 MDT Print View

Thank you James Klein for posting the basic details. Two more questions for whoever wants to answer.

Do you have to send a stove to Roger for this mod or does Roger get them?

If I become a BPL member, can I place an order and still expect to receive a stove before the New Year or is the book closed on this offer?

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Cliff Notes on 10/10/2013 22:06:19 MDT Print View

Hi Rick

> Do you have to send a stove to Roger
No, I supply the whole thing, fully tested.

> If I become a BPL member, can I place an order
Yes. Use email addy below.

> and still expect to receive a stove before the New Year
Barring death and disaster, I would certainly think so.
Batches 1 & 2 have been shipped. I am now into batch 3.

Cheers
roger@backpackinglight.com

Ryan P. Murphy
(rmurphy) - M

Locale: Colorado
stove arrived on 10/21/2013 16:27:43 MDT Print View

My stove arrived today (actually it arrived Saturday but there was no one around to sign for it so I had to wait) and in my VERY limited bench testing I am impressed. It's ridiculously light for a remote canister stove; exactly how light I can't say because I don't have a scale. I really like the "spider" canister click system. There is something so satisfying about the sound of the canister clicking onto the attachment before actually sealing the connection. I was surprised that in liquid feed mode I can actually see fuel traveling through the fuel line. I will report further when I've done some real world testing. I'll be using it throughout the fall and winter in the Adirondacks and it will see some more serious winter use at altitude in Utah and Colorado in January. Beautiful work Roger. Now if only I could get my hands on one of your winter tunnel tents...

Jon McConachie
(hyker) - MLife

Locale: Sierra Nevada
Evolutionary winter stove on 10/21/2013 19:26:40 MDT Print View

My stove arrived today and it is a work of art. 87g per my kitchen scale.
Thank you Roger.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: Cliff Notes on 10/22/2013 00:08:06 MDT Print View

> > and still expect to receive a stove before the New Year
> Barring death and disaster, I would certainly think so.
The X axis power driver on my CNC has suffered a slight misfunction and is away being repaired. This will create a delay of a few days in manufacturing.

No, 'slight misfunction' does not mean a catastrophic bang with smoke everywhere! It just means that the safety circuit started to trigger becasue of excess current draw at high speed. We know what the problem is likely to be - a damaged FET in the H-bridge.

Do not adjust your set, we will soon be back to your scheduled program.

Cheers

Edited by rcaffin on 10/22/2013 00:08:41 MDT.

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
stove arrived on 10/22/2013 09:33:12 MDT Print View

Yup, mine arrived yesterday. I did some preliminary tests and was getting about 10-12g/L, with no tweaking. Weight was 86g.

Jan Rezac
(zkoumal) - MLife

Locale: Prague, CZ
Stove arrived + safety issue report on 10/31/2013 08:57:57 MDT Print View

Roger, thanks for perfect timing. The stove arrived last week just on the day I was leaving for a four-day trip. It was an opportunity to test it a bit, although we cooked mostly on fires.

The stove is very nice and light and the attention paid to some construction details is really amazing. I like it a lot.


However, I've encountered one quite serious issue: I was screwing the valve onto the canister and although the safety valve lever was in the "off" position, the gas started to leak. At first, I wanted to tighten it quickly to get a seal, but the leaking only increased so I disconnected the canister. It turned out that the brass pin was stuck in the "on" position, regardless of the position of the lever (which I previously turned to "on" for storage and switched to "off" just before use). I found that this can happen because the white body of the safety valve moves horizontally a couple of millimetres and when it is pushed into the valve assembly, the eccentric region is not aligned completely with the pin (see photo). As a result, the pin is caught on the edge of the full-diameter region of the white part, being engaged regardless of the position of the lever. Pulling the white part out a bit fixes the issue for the moment.

valve_problem

Since then, I was checking the pin before every use, and this problem occurred again once or twice. The design should be updated, most easily by making the eccentric region a bit wider to accommodate the possible shift, or by preventing the shifting movement by some other means. I will fix that myself on my stove; I will probably insert a spacer into the valve assembly so that the white part can not be pushed inwards any more.

Additionally, I would prefer to have the on and off positions of the lever to be left and right (with labels on the sides of the black block) rather than up and down. As it is now, the lever in the off position points outwards, and because its quite thin and sharp rod, I'm turning it down when I pack the stove. Being able to pack the stove as is would be nicer, because the stove will be ready (in off position) for next use.

Edited by zkoumal on 10/31/2013 13:53:04 MDT.

Jan Rezac
(zkoumal) - MLife

Locale: Prague, CZ
Stove problem fix on 10/31/2013 14:34:11 MDT Print View

I have just fixed the problem described in my post above. To prevent the safety valve (white part) from being pushed inside, I inserted a spacer that fills the small empty space between this part and the aluminium hose connector on the other end.

I cut a thin (1.4 mm) ring from a plastic tube of approximately right diameter. A piece of this thickness perfectly fills the empty space. To allow free flow of the gas from the outside into the ring, I cut several tiny notches into one face of it.

It works well, now the valve can not be moved into the position where the pin would be blocked.

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Stove arrived + safety issue report on 10/31/2013 15:00:34 MDT Print View

Roger, is there any necessity for a world wide product recall?

--B.G.--

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Stove arrived + safety issue report on 10/31/2013 19:33:12 MDT Print View

Hi Jan

If that photo was taken with the pin removed and the cam valve in place with the retainer plate screwed in properly, I am a totally puzzled by the position of it. It just looks wrong. It should NEVER get there.

Actually, I am really puzzled by the whole photo. Could you send me the original photo without cropping please.

If you wish to post the stove back I will check it out and fix whatever the problem is, no charge. It really is not meant to do that.

Cheers
roger@backpackinglight.com

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Re: Stove arrived + safety issue report on 10/31/2013 19:47:18 MDT Print View

That couldn't have been the result of a customs inspection, could it?

--B.G.--

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Stove arrived + safety issue report on 11/01/2013 02:51:48 MDT Print View

Hi Jan

> I would prefer to have the on and off positions of the lever to be left and
> right (with labels on the sides of the black block) rather than up and down.
Yes, I thought of this, but it failed one test.

7 pm, bad weather & snow & wind, very cold & tired, dim light, incipient hypothermia from pitching the tent. Goes to set up stove. Which way is OFF? Left or right? Can't even read the writing.

Solution: handle out of canister, pin out; handle in towards canister: pin into canister.

Gas is dangerous. I never ever assemble the stove without checking: safety valve off, needle valve gently closed.

Cheers

Jan Rezac
(zkoumal) - MLife

Locale: Prague, CZ
Stove problem on 11/01/2013 03:49:54 MDT Print View

Roger, I sent the larger photo via e-mail.

I'm curious whether somebody else can reproduce it. Here are the steps that would lead to this problem if it affects your stove (do not attach the cannister):

1) Set the cam valve to the "off" position (lever points away from the threaded connector)

2) Position the whole thing so that the canister connector end points downward. Gravity pulls the brass pin down, out of the cam. Press the cam valve (the white knob with the lever) inwards. In my stove, it is possible to move it in and out a bit, a little force is needed to overcome the friction of the o-ring inside.

3) Turn the assembly upside down and look into the connector. Turn the cam valve lever - if the brass pin in the connector moves up and down, everything is ok. If it does not (it is stuck in the "on" position), congratulations, you have reproduced the problem. Let us know.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Jan's problem on 11/01/2013 04:20:07 MDT Print View

The photo jan sent me was excellent. I was confused by the small photo shown above.

I may have accidentally included in the pile of white valves for assembly one early unit which was not to spec. Such a unit would cause this problem. I await reports from anyone else who has this problem. In the meantime, the dimensions in the master drawings and CNC programs have been tweaked slightly to prevent this from happening again. It's a beta test after all!

Jan's solution used a bit of tubing, but not everyone will have something suitable. If your stove shows signs of this problem, there is a much simpler cure (which has been tested). Take a short bit of 1 to 1.2 mm copper wire and form the letter C. Round the two ends so they are not scratchy. The OD should be about 7 mm, and must be < 8 mm. It has to fit easily into the 8 mm bore in the block. The two ends of the wire should not touch: it's a C, not an O. Remove the connector (do NOT lose the screws!!!), drop the loop down the hole, jiggle it flat, replace the connector, replace the screws. Caution: do not use hard wire, and do **NOT** scratch the inside of the 8 mm bore! The loop should fall in easily.

Cheers
Roger

Jan Rezac
(zkoumal) - MLife

Locale: Prague, CZ
Stove modification for lightweight butane canisters on 11/01/2013 15:55:11 MDT Print View

After fixing the problem with the valve, I moved to hacking the stove so that it can be used with lightweight butane canisters (for refilling lighters). The stove with a full canister (50 g of gas) weights less than 160 g!

I created a separate thread for this topic in the MYOG section:

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=83643

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Stove modification for lightweight butane canisters on 11/02/2013 04:31:52 MDT Print View

> I moved to hacking the stove so that it can be used with lightweight butane canisters
> (for refilling lighters).
Oh My Gawd. My stove has been hacked already!
I suppose I have to see this as a compliment ... :-)

(Jan and I have been discussing this by email. Interesting ideas kicked around.)

Cheers

Anthony Britner
(ant89) - F - M

Locale: North Wales, UK
my comments on 11/02/2013 15:13:31 MDT Print View

I'd certainly be interested, mostly in the 116T version without the burner as I already have one. It seems to make sense to use the burner I already have available.

Edited by ant89 on 11/02/2013 15:16:05 MDT.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: my comments on 11/02/2013 16:55:52 MDT Print View

email me.

Cheers
roger@backpackinglight.com

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Update on beta test feedback on 11/11/2013 00:52:38 MST Print View

Hi all

Yes, I have received some feedback from beta-testers. The resolved issues are:

* Tab at bottom of leg used for opening them could be bigger, for gloves.
Good idea, and I have updated the drawings and the programs. I will be making some more legs soon, with the bigger tabs.

* Brass pin in canister connector not retracting.
This was probably partly due to a bad clash of tolerances, but also to the white cam valve being pushed a long way into the canister connector while the brass pin was fully out. The user solved that problem by pulling the white valve back out by a millimetre or two using the Ti wire handle. Should any other user have this problem, please contact me. The cure in the field is to pull the valve back out a millimetre or two - it won't come right out as the retainer plate holds it in. But I do have an extremely simple 'fix' for the problem as well.

* Tiny flame
User cleaned out the needle valve, removing two little bits of aluminium swarf. My fault, apologies, more care with cleaning needed.

* Filler cord jammed and broke when user tried to extract it from hose
This required a detailed examination of the hose, which was returned to me. It turned out that the clearances I had been using were a shade small for comfort. I had to buy some special drill bits to deal with this: 1.25 mm and 1.35 mm. They exist, they just are not common. However, with those drill bits the problem was eliminated. All future stoves will have the improved clearances. Anyone with an existing stove who want the upgrade should contact me. You will need to remove the hose and post it back to me.

There is one more bug which has yet to be fixed: I am waiting on the parts being returned.

Meanwhile, I have repaired my CNC machine and started machining again. Happy days!

Cheers

Jeff McWilliams
(jjmcwill) - M
Temperature limits? on 11/20/2013 21:15:13 MST Print View

On about 10/09, jerry adams stated he felt the stove would be good down to about 12F.

Is that widely regarded as an accurate estimate of its lower range of usability?

I'm planning a trip to the Adirondacks at the end of the year. Last year's temps in the area averaged 15F. Accounting for elevation change of 2000', that's about 11F in the proposed camp area. However, several days saw lows of 0F to -3F, which could be almost -9F at elevation. If an inverted canister is useless at that altitude, I guess I need to take a white gas stove regardless of the "cool factor" of Roger's stove.

I have the 116T burner version, and was sort of hoping to take it with me, but not at risk of being unable to melt snow and boil water.

Douglas Frick
(Otter) - MLife

Locale: Wyoming
re: temperature limits? on 11/20/2013 21:55:57 MST Print View

> On about 10/09, jerry adams stated he felt the stove would be good down to about 12F.
> Is that widely regarded as an accurate estimate of its lower range of usability?


It's possible Jerry was referring to the Winter Stove running from a pure-butane canister, or perhaps the original Fire Maple canister-top stove, without any form of warmth being transferred to the canister. (+12F is the approximate boiling point of iso-butane.) The context of his post wasn't quite clear.

However, +12F is NOT a lower limit for an inverted-canister iso-butane/propane stove, such as this Winter Stove. That, in fact, is exactly why and how Roger's design differs from the original Fire Maple stove. As long as the propane in the canister can vaporize (the approximate boiling point of propane is -40F), then the pressure from the propane gas at the 'top' of the canister will force the iso-butane/propane liquid out of the (inverted) canister valve and down the fuel line.

I wouldn't expect the stove to run quite as low as -40F without some help, however. My Coleman Exponent stove gets a bit balky below -30F under worst-case conditions: canister sitting out all night, exposed to the air and sky and insulated from the ground, then allowed to cool even more as the stove runs. However, simply putting the canister in a shallow pan of cold water (or even packed in relatively-warm ice or snow) should allow the Winter Stove to run when the air temperature is below -40F.

Edited by Otter on 11/20/2013 21:57:21 MST.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Temperature limits? on 11/20/2013 23:25:31 MST Print View

According to wikipedia, the boiling point of isobutane is 8 to 16 F.

If you have propane and isobutane, and operate at the boiling point of isobutane, the propane will evaporate more than the isobutane so after a while, you will be left with mostly isobutane. What do they have, 15% propane? You should be able to use that much.

Then, with an inverted stove, it will only work above the boiling point of isobutane, which I said might be 12 F. Maybe you could go down as low as 8 F.

This is theortical, I haven't used an inverted stove. Maybe the actual boiling point of your canister is different. It also depends on altitude I believe.

You can always use one of the techniques to warm canister, like with body heat. An inverted stove would work much better because it has very little evaporative cooling as happens with upright.

Edited by retiredjerry on 11/20/2013 23:27:04 MST.

Douglas Frick
(Otter) - MLife

Locale: Wyoming
Re: Temperature limits? on 11/20/2013 23:46:41 MST Print View

Jerry, the problem you describe applies to canister-top stoves (canister sits upright, with burner on top) operating in the +12F range, where the propane alone boils and burns off, leaving 3/4 canister of (useless) liquid iso-butane. However, the key to the liquid-fed Winter Stove working at well below the boiling point of iso-butane is that the canister is physically _inverted_ after the stove warms up: the "top" of the canister (with the valve) is pointing down, and the "bottom" (concave) part of the canister is facing up.

As long as the temperature of the canister is above -40F (boiling point of propane), then as the pressure in the canister drops, some of the propane will boil out of the liquid iso-butane/propane mix. The propane gas floats upwards, and so occupies the space between the liquid mix and the uppermost part of the canister (its concave bottom). There's no way out for the propane gas, so the pressure forces the liquid iso-butane/propane _mix_ out of the valve (which is the lowest point), along the fuel line to the stove, where heat from the lit stove (transferred through the heat shunt or a vaporizer loop) converts the liquid mix into vapor, which burns.

So, the stove should work down to the boiling point of propane. Once all the liquid iso-butane/propane mix has been pushed out of the canister's valve, its last gasp will be mostly pure propane gas, leaving an empty canister.

Edited by Otter on 11/21/2013 00:02:46 MST.

Stuart R
(Scunnered) - F

Locale: Scotland
Re: Re: Temperature limits? on 11/21/2013 02:11:56 MST Print View

Douglas, you need to read about the effect of cold on gas canisters

The gas above the liquid mix does contain propane, but it also contains butane (and/or iso-butane, depending on the contants of the canister). As a rough analogy, think about air - it contains water vapour at temperatures well below the boiling point of water. The proportion of propane depends on the constituents of the liquid mix, but is typically 60-70% propane. It does not depend much on temperature - the percent propane gas will be almost the same at -40F as at +40F. This is not the same as the air/water vapour analogy, but then the boiling point of water is vastly different from oxygen and nitrogen.

"So, the stove should work down to the boiling point of propane."

Definitely not.
The minimum operating temperature will depend on the pressure generated by the aforementioned propane/(iso-)butane gas mixture. For canisters such as MRS IsoPro Red (20/80% propane/iso-butane), Coleman (30/70% propane/n-butane) and Primus Power Gas (25/25/50% propane/iso-butane/n-butane) you can expect the stove to work with an inverted canister down to 0F (-18C).

Edited by Scunnered on 11/21/2013 02:27:31 MST.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re Stuart's comments on 11/21/2013 02:51:02 MST Print View

I'm with Stuart here.

One of the most common mistakes is to think that the propane in a butane/propane mixture will behave the same way as 100% propane. It won't. Read the article Stuart referenced - yeah, he and I wrote it!

Cheers

Douglas Frick
(Otter) - MLife

Locale: Wyoming
Re: Re: Temperature limits? on 11/21/2013 05:47:01 MST Print View

Oh well, back to school...

Jeff McWilliams
(jjmcwill) - M
Temperature Limit on 11/21/2013 06:09:24 MST Print View

So, if I understood the article that Stuart and Roger wrote, it says,

"When the canister is used upside-down (inverted) with a stove which has been designed for this mode of operation, the effect of decreasing % propane described above is avoided."

Does that mean I could look at Figure 4: Threshold Temp(C) vs Gas Remaining at given Pressure, and assume 100%?

At 3000', that would give 20/80 a threshold temp of about -26.5C, and 30/70 a threshold temp of -30C.

Is that correct?

I like the extra "oomph" of Kovea's 30/70 compared to 20/80, which is what MSR IsoPro Red and JetBoil (I think) contains. Unfortunately, I've not seen Kovea canister fuel for sale anywhere in my area.

Stuart R
(Scunnered) - F

Locale: Scotland
Re: Re: Re: Temperature limits? on 11/21/2013 06:25:25 MST Print View

Learning is good. To be fair, most of the referenced article is about upright stoves, as that is where there are interesting effects that need explanation. However there is a paragraph about inverted canisters. In essence, using a canister inverted preserves the propane % content and so the boiling point of the mixture remains at the "100% remaining" point shown on the graphs. In other words, the minimum operating temperature is preserved throughout the life of the canister, unlike the upright canister situation.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Re: Temperature limits? on 11/21/2013 08:11:48 MST Print View

"Jerry, the problem you describe applies to canister-top stoves (canister sits upright, with burner on top) operating in the +12F range, where the propane alone boils and burns off, leaving 3/4 canister of (useless) liquid iso-butane"

Oh... Good point. Another reason for using an inverted stove : )

Having 20% propane for an upright doesn't make that much difference, although if you just had one or maybe two really cold nights it would be pretty uesful.

Stuart R
(Scunnered) - F

Locale: Scotland
Re: Re: Re: Temperature limits? on 11/21/2013 08:49:50 MST Print View

Iso-butane is not useless. In fact, if you are using an upright stove you want the highest proportion of iso-butane that you can get: MSR IsoPro or Jetboil are good candidates. It's regular n-butane that is useless in an upright stove in winter.

On the other hand, with an inverted canister, butane vs iso-butane doesn't matter much, it's a high propane content you want.

Reason: with an upright stove, any propane is quickly used up, so it's what's left (butane or iso-butane) that matters. With an inverted canister, the propane is preserved (in % terms), and the more propane the better for low temperature use.

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Re: Re: Re: Temperature limits? on 11/21/2013 09:07:03 MST Print View

Propane is a slightly smaller molecule than butane, so it tends to concentrate slightly near the bottom. So it isn't quite 100%, but clse enough not to worry. Gravitional effects are very slight compared with solutes and usually ignored.

Pressure changes (as in a closed canister or one running at constant low power) will dictate that canister temperture will change for "toppers." The liquified gas never really boils in a pressure vessel. Rather, the vapor pressure/gas pressure is maintained at an equivalency, at the temperture it is currently at. (This is why we don't ever hear a canister burping and boiling inside.) By drawing from the bottom, in liquid form, we reduce the effect of cooling on the container, since the liquid has 1/200-1/300 the volume of the gas(given some delta-T.) The heat normally lost through drawing the gas off a topper, is supplied by the heat shunt on Rogers stove. As long as there is enough pressure to force the liquid out of the cannister, through the tubing, valve and and connectors, the stove WILL operate. Though, there will be a lot of fluttering to start with till it reaches a balance. How much is needed? Probably not much. I would guess you could blow water through the system. So maybe 3 atmospheres? This would easily take the stove down to -40 or so, since there is some vapor pressure evan at -40F/-40C(yup, same number...darn COLD) as long as there is some propane in the cannister. Likely closer to -50F(about 4-5 bar in a canister,) since the propane doesn't actually have to boil to hit these pressures, though the stove may not light too easily since the mixed liquid would not gasify too well.

EDIT: Sorry, the tables I looked up had both Bars and PSI. The -40F/C temps were based on that. My mistake, it should be about -25C.

Edited by jamesdmarco on 11/21/2013 14:04:24 MST.

Stuart R
(Scunnered) - F

Locale: Scotland
Re: Re: Re: Re: Re: Temperature limits? on 11/21/2013 09:32:55 MST Print View

As usual, I don't understand a word you write James.

Propane is a slightly smaller molecule than butane, so it tends to concentrate slightly near the bottom.

Really? At the bottom of what? I rather think the thermal energy of the molecules will ensure a pretty even distribution in something a small as a canister on planet earth.

The liquified gas never really boils in a pressure vessel. This is why we don't ever hear a canister burping and boiling inside.

Take a cold canister, put it in some warm water and listen - you WILL hear it fizzing inside.

there is some vapor pressure evan at -40F/-40C(yup, same number...darn COLD) as long as there is some propane in the cannister

Sure there is some vapour pressure due to the propane, there is even some due to the butane at -40F/C BUT the combined vapour pressure is LESS than atmospheric pressure (unless you are on the summit of Everest:-) so when you open the valve, air will go INTO the canister: gas will not come out.

Douglas Frick
(Otter) - MLife

Locale: Wyoming
Re: Re: Temperature limits? on 11/21/2013 11:56:26 MST Print View

Jerry, you might want to ignore the details in my explanation, after I got schooled on it. :-)

An (important) correction: I checked my stove log, and found that the coldest I'd operated the Coleman Exponent stove with Powermax fuel UNDER THE CONDITIONS I STATED (fuel actually at ambient air temperature) was -25F, not -30F. I've used the stove at -30F and lower, but on those trips I always did something to keep the canister warmer than ambient.

So, I've been trying to reconcile my experience with the operational limit of my Coleman Exponent stove being -25F, with Stuart's comment "you can expect the stove to work with an inverted canister down to 0F." However, after looking at the charts, it seems both of our statements can be correct (after mine was corrected ;-). The left chart of Fig. 4, typical canister mix at sea level limit is -23C, +5 degrees to get some working pressure, so -18C = 0F. The right chart, Powermax fuel (30% propane, 70% iso) at 10K altitude (where I use the stove) limit is -36C, + 5, so -31C = -24F. Assuming I haven't screwed up again, that explains why my stove operated (poorly) at -25F.

Thanks, Stuart and Roger, for reminding me about your excellent article. I forgot just how much difference mix and altitude make; I'll try to remember that when I'm outside Wyoming. Also, thanks for clarifying the mixed-gas boiling science.

To the original question, perhaps the most relevant point is that, while all canister stoves stop operating at some low temperature if you don't do anything to keep the fuel warm, you can run these stoves regardless of the air temp if you simply keep the canister at, say, +32F. As mentioned in this thread (and in the article), that can be done with a pan of liquid water. The bottom cover for my original JetBoil is has a diameter just slightly larger than a small fuel canister, so I set the assembled stove in the cover and fill it with water. After a while a skim of ice forms on the water, but it runs just fine. For my Coleman stove, I usually work-pack the canister in snow to keep it 'warm' and prevent it from chilling in the overnight air.

Edited by Otter on 11/21/2013 13:34:51 MST.

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Re: Re: Re: Re: Re: Temperature limits? on 11/21/2013 14:00:01 MST Print View

"Propane is a slightly smaller molecule than butane, so it tends to concentrate slightly near the bottom.

Really? At the bottom of what? I rather think the thermal energy of the molecules will ensure a pretty even distribution in something a small as a canister on planet earth."

Yeah, very small, ignore it.

"Take a cold canister, put it in some warm water and listen - you WILL hear it fizzing inside."

Yeah, that can happen. But this doesn't effect the over-all steady state pressure as you use the stove, well slightly decreasing. You just need to calculate at the new temperature. In your example, once it hits around 32F/0C it should stabilize again, within a minute or two, I would guess. Boiling is simply the explosive release of vapor pressure. In a closed system, this cannot happen, except as you say, by greatly changing temperature/pressure conditions. The valves(lindal and control valve) *limit* the flow of gas and/or liquid. There needs to be positive pressure in the canister for the stoves to work. The pressire also acts on the liquified gas varying the vapor pressure AT the boiling point of the new system. Not above it or below it. (Actually as you burn the gas it is slightly decreasing, drawing more gas out of the liquid state, but not really boiling, vapor pressure is usually enough.) Like boiling water in a closed vessel. Unless you actually flash heat it, no boiling happens till it actually explodes, then ALL the superheated water (at the new lower pressure) will try to boil till it reaches a steady state again.

The data was from: http://www.engineeringtoolbox.com/propane-vapor-pressure-d_1020.html
Your right, I just realized the tables were not all in bars, the F temps are in PSI. Sorry about my mistake. Looks like -13F/-25C will supply about 2 bars. Again, my apologies. I will correct it in the above note.


Anyway, from this it is possible to conclude that the interior surface of the LP gas inside a canister may be more important than we previously guessed. The concave bottoms, once exposed inside, probably cause lower volumes of gas to be available for use...perhaps the last sixth or so of the canister.

Stuart R
(Scunnered) - F

Locale: Scotland
Re: Re: Re: Temperature limits? on 11/21/2013 14:11:25 MST Print View

I'm pleased that we are both right Douglas :-)
My statement "you can expect the stove to work with an inverted canister down to 0F." was beng conservative, an inverted canister can work at lower temperatures depending on your circumstances whch I was unaware of.

You say you were using a Powermax canister, which alters things. I thought that in the US they contained 35% propane, 65% n-butane? (I believe they contained 40% propane in the rest of the world, Roger will correct if I am wrong here) If the first assumption is correct, then the boiling point of this mixture is -15F at sea-level and -31F at 10k feet. So if your ambient was -25F then this would work, just.

Edited by Scunnered on 11/21/2013 14:14:55 MST.

Stuart R
(Scunnered) - F

Locale: Scotland
Re: Re: Re: Re: Re: Re: Re: Temperature limits? on 11/21/2013 14:25:04 MST Print View

James, that table is for 100% propane. You need to look at these tables for propane/butane mixtures:
http://www.engineeringtoolbox.com/propane-butane-mix-d_1043.html
Note that this table is refering to the % gas mixture, which is different from the % liquid (weight) mixture shown on canisters: a canister containing 30% propane in the liquid has about 70% propane in the gas mixture, which according to these tables has a positive pressure (Psig) down to around -25F

The concave bottoms, once exposed inside, probably cause lower volumes of gas to be available for use...perhaps the last sixth or so of the canister

You lost me again...

Edit - correct link

Edited by Scunnered on 11/21/2013 14:41:51 MST.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Powermax on 11/21/2013 14:36:04 MST Print View

As far as I can tell, the Powermax canisters did not state the fuel composition - and I suspect it changed over time too. But they had the right design (for winter)!

Cheers

Andy Stow
(AndyS) - F - M

Locale: Midwest USA
Re: Re: Re: Re: Re: Re: Re: Temperature limits? on 11/21/2013 14:51:55 MST Print View

"Anyway, from this it is possible to conclude that the interior surface of the LP gas inside a canister may be more important than we previously guessed. The concave bottoms, once exposed inside, probably cause lower volumes of gas to be available for use...perhaps the last sixth or so of the canister."

If you're saying what I think you are, that since in upright use the dome will expose leaving a donut of liquid surrounding a shallow metal dome, with the liquid surface generating vapor pressure and the metal surface generating none... no, pressure does not work that way. The gas volume will stay at the vapor pressure of the remaining liquid until no liquid is left. The wetted surface and its shape are not relevant.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Manufacturing Update on 11/21/2013 14:53:31 MST Print View

Time to update on status.

I have shipped a couple of batches, and had nearly completed yet another batch when the X axis on my CNC died. I thought it was mechanical and stripped the machine down and rebuilt the ball screw drive. A word of advice: don't do this yourself!

But the fault reappeared. The power driver for the X axis was telling the world it was seeing an over-current: in excess of 15 A. Normally it draws about 200 - 300 mA. So I sent the power driver off to be checked. A small fault was found and one section was replaced.

However, the same over-current fault reappeared with the new unit. By now I was getting a bit suspicious. I had installed current meters on the machine to monitor the loads, and faulting at 15 A was not credible. Also, when something fails at 15 A, it does not start working again when you hit the reset button. Things ... tend to melt at those currents.

Some electronics diagnostics work followed, plus discussions with the original designer. I began to suspect the fault-detection circuit itself. That is, no actual fault was happening, but a false trigger was being created.

In an effort to reduce the effects of noise on the fault detection, a capacitor had been added as a filter at the last minute. This told me there had been noise problems for a start. Hum. Unfortunately the capacitor had been added in an apparently obvious place (albeit unusual) which was actually very, very wrong. Things get a bit esoteric here, but I had published a research paper on this circuit effect in 1975! It had the potential to worsen the effect of certain low-probability forms of noise.

I have modified the circuit, and started machining again yesterday. We will see how good my diagnostics have been, won't we? Some further tweaks may be needed. My apologies to all the beta-testers who have been waiting.

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Manufacturing Update on 11/24/2013 16:45:20 MST Print View

CNC still running OK.
Legs all made for the next batch. Didn't take long.

All I am waiting on now are the 4 mm SS grub screws & nuts that hold the legs on. I could use plated steel, but that can rust. Not good enough.

The screws were ordered 10 days ago and were 'ex stock for delivery within 24 hours'. But because another ex stock item on the order was not really in stock, the whole order was held up. They were going to wait the remaining 2 weeks to get the last part in to make up the full order. No feedback, no emails asking if I needed the goods soon, .... Scream of rage!

OK, stoves all going into pressure test today, followed by burn test. When the screws arrive the legs will be added. Gotta have legs ...

Cheers

Desert Dweller
(Drusilla) - M

Locale: Wild Wild West
Evolution of..... on 11/24/2013 16:59:03 MST Print View

Your persistence and tenacity are to be commended.
Nothing worse when a tool breaks down when doing a project.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Batch 3 shipped on 12/02/2013 17:01:42 MST Print View

Well, a (not so) quick trip to the Post Office and batch 3 has been shipped.
They were assembled, pressure tested for leaks (no leak is accptable), flow tested (any blockages or unacceptable restrictions) and burn tested. The last verifies that the flame shape is correct and that the heat exchanger system is working.

I did get one stove with a really weird flame shape, way off to one side. Turned out the jet had a small obstruction at one side of the hole so the gas jet came out off-centre. That was corrected by simply cleaning the jet.

OK, back to the workshop.

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Beware Chinese canisters! on 12/04/2013 04:08:10 MST Print View

Hi all

One tester has reported that his stove ran for a short while (inverted) then died completely. This seemed a trifle odd to me, but further clues were forthcoming. He had been using a Primus canister, inverted, when it died. Aha!

Now, I too have used Primus canisters, but there seem to be a couple of different sorts. Some work just fine, but one which was labelled Primus/(campstuff)/(something else) had been made and filled in China. After all, who else would label the canister as having 74.48% butane? In poor English too, if I remember correctly. It was ... cheaper.

Anyhow, when I tried to use this Chinese Primus canister my stove died - twice, and quickly. Each time I found fine dust or gunk lining the inside of the stove. I returned the two canisters to the shop and got all my money back. I did wonder later what I had said in the shop, as shop keepers do not like refuding full price for a used thing. Pity - i should have kept one of them as 'evidence'.

So I suggested to the stove owner he clean the valve and jet. He actually stripped the entire stove down and cleaned stuff (black gunk) out of everywhere. Now he reports it runs just fine - on an MSR canister.

My suspicion is that 'they' are filling the canister with unfiltered, undistilled, unpurified gas straight out of the LPG well - or similar. The fine dust may be dirt from the gas well - or corrosion from the plant?

You have been warned!

Cheers

peter vacco
(fluff@inreach.com) - M

Locale: no. california
Re: Beware Chinese canisters! on 12/04/2013 07:34:25 MST Print View

possibly the best-ever .. ever , thread on bpl.
gas stratification (it happens. it really really does). eluding to the possible return of dreaded and possibly fatal brownian motion discussions of 1997.
orifice obstructions and flame disruptions (it takes effectively nothing to make this happen). and it's related to another pet subject of mine (ox/acy cutting).
machine tools with perhaps shunt resistance demons. and sketchy demons they be too, with their comings and goings. all now banished from my life with the simple inclusion of a 480vac isolation transformer. (smooth and calm now ... like demerol, but for electricity)
electrical issues with capacitors (coming soon to the polar bear fence ! )

all this ! and i don't even OWN a frikk'n "gas stove".

cheers,
v.

Stuart R
(Scunnered) - F

Locale: Scotland
Gas stratification on 12/04/2013 10:06:26 MST Print View

Yes but "analysis shows that stratification does occur, but it requires a column of static air several kilometers high to have a major impact" i.e. not in your average gas canister.

http://chemdaq.blogspot.co.uk/2012/09/gas-stratification-is-not-relevant-to.html

Go on, get a canister stove, you know you want to...

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Stove in use at -30 C (-20 F) on 12/06/2013 15:57:40 MST Print View

Hi All

A photo from one of our beta-testers, Douglas Frick (to whom my thanks).

Douglas Frick Winter Stove at -30 C

Douglas tells me it was -30 C (-20 F) when this photo was taken. A shade cool imho. But clearly the stove can be used at that temperature.

Cheers

Edited by rcaffin on 12/06/2013 15:58:16 MST.

Rick M
(rmjapan) - F

Locale: Tokyo, Japan
Re: Stove in use at -30 C (-20 F) on 12/06/2013 17:36:37 MST Print View

At such -30C extreme cold, does one still follow the standard procedure of starting the stove with the canister upright and then inverting it after a minute or so once the preheat tube gets hot?

Nick Gatel
(ngatel) - MLife

Locale: Southern California
Re: Re: Stove in use at -30 C (-20 F) on 12/06/2013 18:45:00 MST Print View

"At such -30C extreme cold, does one still follow the standard procedure of starting the stove with the canister upright and then inverting it after a minute or so once the preheat tube gets hot?"

Looks like only one person knows for sure.

With the old Gerry and Mark III stoves (and similar), you had no choice. The were liquid fed, but upright.

Robert Blean
(blean) - MLife

Locale: San Jose -- too far from Sierras
What do you suggest for a wind screen? on 12/06/2013 18:52:36 MST Print View

Roger,

What do you recommend using for a wind screen with your stove?

Edited by blean on 12/06/2013 19:30:45 MST.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Stove in use at -30 C (-20 F) on 12/06/2013 19:10:42 MST Print View

> At such -30C extreme cold, does one still follow the standard procedure of starting
> the stove with the canister upright and then inverting it after a minute or so once
> the preheat tube gets hot?

It's a bit more complex at -30 C. For a start, the gas canister will not be warm enough to push out ANY fuel if it is at ambient, and this goes for ANY canister stove. So you need to get the canister a bit warmer than -24 C to get any joy (ie fuel) at all.

For ANY inverted canister stove at very low temperatures, some skill is needed. You can start with the canister upright and hope to get some gas out - it will be mainly propane with just a little butane. But running the stove for some time with the canister upright could be said to be storing up problems for the future, as the %propane will be falling rather fast. See http://www.backpackinglight.com/cgi-bin/backpackinglight/effect_of_cold_on_gas_canisters.html for an in-depth discussion of what happens inside the canister at very cold temperatures.

You might like to note there is a Coleman Xtreme behind the lit stove, to the left. The canister for this stove is the Coleman Powermax, and this always give a liquid feed. You cannot get a gas feed out of it. So the standard method for lighting an Xtreme is to first warm the stove in your hands (which happens as you set the stove up), then to light it at very low power. There may be a few burbles of orange flame right at the start - no matter. As the flames heat the preheat tube, the stove starts to function in the normal inverted canister mode.

You can do exactly the same with my stove and any canister. That is, you can start with the canister inverted if you wish. Just run it kinda slow for a little while as the heat shunt warms up. Gradually increase the power when the stove body feels warm.

One has to be flexible ...

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: What do you suggest for a wind screen? on 12/06/2013 19:26:50 MST Print View

> What do you recommend using for a wind screen with your stove?

Have a look at When Things Go Wrong, about half way down. The pic is labeled 'Cooking dinner in the vestibule of the tent'. That is a Trail Designs windshield - one of the plain unvented ones. I leave a gap where the stove control valve handle sticks ou, may 20% of the circle. I leave a gap of about 15 - 20 mm between the pot and the windshield. OK, it's probably a bit more in this photo - it isn't really critical. And I have the windshield come about 1/2 way up the side of the pot, or maybe 3/4 of the way.

But any similar bit of aluminium shim or heavy foil will do just fine.

Cheers

Edited by rcaffin on 12/06/2013 20:40:24 MST.

Douglas Frick
(Otter) - MLife

Locale: Wyoming
Re: Re: Re: Stove in use at -30 C (-20 F) on 12/08/2013 21:32:50 MST Print View

Sorry for not responding sooner, I was out camping this weekend.


>At such -30C extreme cold, does one still follow the standard procedure of starting the stove with the canister upright and then inverting it after a minute or so once the preheat tube gets hot?


I had three inverted-canister stoves set up: the beta Caffin stove, a Coleman Xtreme, and an MSR Whisperlite Universal. All had set out overnight (low of -34C / -29F) with their canisters attached (so they wouldn't warm by handling), exposed to the air, and insulated from the snow with silicone pads. The Caffin stove had a new Snow Peak Giga Power 110g canister. I lit it with the canister upright (small flame) and _immediately_ inverted the canister, without waiting for the heat shunt to warm up. As expected, it flared up; I dropped my pot on the burner; and after about 20 seconds, the heat shunt warmed and it settled down to a nice flame. As Roger mentions in his post above, it was burning mostly propane at the start, which is why I immediately inverted it to save the propane for pressure. The wind had dropped so I didn't need a windscreen, and the heat from the burner warmed the canister a bit more, which kept the stove going without intervention.

The Coleman Xtreme had a Powermax canister that was about 1/3 full. It wouldn't start until I poured some (precious body-temp) water over the canister. It ran after that, but the flame didn't really get roaring until I heated more water to pour over the canister. If I had set the canister in a basin before pouring, I would have wasted a lot less water.

The MSR Whisperlite Universal had a 3/4-full Snow Peak canister, and it wouldn't start. I closed the valve, inverted the canister, and poured warm water into the concave base. I let it sit for a minute, so the heat from the water could work its way down the side of the canister to the liquid fuel, then lit it in fireball mode. It flared a while until the preheat tube warmed up, then settled down nicely. The water in the bottom of the canister soon froze solid, but it had done its job of producing sufficient gas pressure.


So two of the three stoves were non-starters (insufficient gas pressure in the partially-used canister to force either gas or liquid down the hose to the burner), and probably the only reason the Caffin stove started was that it had a brand-new canister. However, by simply applying a bit of warm water to their canisters, both non-starting stoves soon ran fine. I intentionally tried starting the stoves with chilled canisters, and inverted them cold, to see if/how they would work under these conditions. If I had either slept with the canisters or set them in water baths before attempting to start the stoves, the stoves would have had no problems starting and properly heating the preheat shunt/tubes, and thus I could have avoided the flare-ups from burning liquid-state fuel. I should also mention that I slept under a tarp, so the flare-ups weren't a problem; there's no way I would invert the canister without a hot preheat shunt/tube in the vestibule of a tent!

I also tested an upright-canister stove, but I'll post about that in a separate message.

Edited by Otter on 12/08/2013 22:01:35 MST.

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Re: Re: Re: Stove in use at -30 C (-20 F) on 12/08/2013 22:08:23 MST Print View

I might point out one more trick. When you get up on a cold morning and you think you will need some warmth to start these canisters... just drain the dragon, so to speak. The fluid is plenty warm, and it is going to go to waste anyway. Just make sure that you don't get frostbite in this process.

--B.G.--

Douglas Frick
(Otter) - MLife

Locale: Wyoming
UPRIGHT CANISTER STOVE in use at -30 C (-20 F) on 12/10/2013 20:57:29 MST Print View

I also wanted to test an upright canister-top stove under challenging conditions.


upright canister stove at -30C / -20F


That is a stock Fire Maple FMS-300t stove with a nearly-empty canister (approximately 3 grams / 0.1 ounce of fuel left), which is about the worst case for cold weather. At room temperature, I had shaken the canister and couldn't hear any liquid slosh. With the canister/stove combo having sat out overnight and exposed to ambient air at -30C / -20F, I opened the valve and held a lighter to it: no hiss, no flame.

I then set the canister in a shallow cold-water bath. (I used a lid from a jar of protein powder; 1.0 oz / 28g.) After waiting one minute, the stove lit easily and ran without flare-up, just as if it was warm out. The flame guttered and died after about three minutes--canister empty. Was it just the propane that burned off? Nope. Afterwards, I let the canister/stove combo warm up to room temperature. I lit it, and it held a very small flame for 10 seconds, then went out. Clearly, it had burned the remaining isobutane/propane mix, not just the propane.

I prefer and trust an inverted-canister stove when it's cold, especially for longer burns, melting snow, stabilizing larger pots, with a close windscreen, etc. But upright-canister stoves also work just fine at -30C with proper technique. I think if people knew this trick there would be a lot less trepidation about using canister stoves in the cold.

Edited by Otter on 12/10/2013 20:59:34 MST.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Update on the UL Winter Stove project: ex stock on 01/01/2014 21:58:03 MST Print View

5595: 19 winter stoves lined up finished

Well, this is batch 4, all 19 of them. 8 have been sold already and will be
posted in the next couple of days. The rest are available ex stock. We have
moved from many weeks of lead time to on-the-shelf!

Going from a one-off MYOG hack for myself to a small production process
safe for others has been 'interesting' - especially for an academic. My
respect for all those cottage industries out there has gone up
considerably. The number of production problems encountered was more than I
had expected, but probably par for the course.

My CNC had a recurring 'fault' in the electronics which kept shutting the
machine down. The system said it was getting a 15 Amp over-current problem
on one of the drive motors - which sounded bad as things start to melt at
those current levels. It turned out to be a design fault in the
fault-detection circuitry. I modified the circuit so it would work
properly.

There were delays in getting some parts - with the supplier in one case not
bothering to tell me that there would be a 3 week delay for an order quoted
on their web site as 'ex stock'. We 'discussed' the matter (politely!), and
the critical parts were supplied Express (overnight).

One of the supplied components changed source during production, with the
new part being 'less than satisfactory'. I think the new part came from
China, but can't be sure. I had to find a completely different part to
replace it and redesign the stove body to handle that. Fortunately that was
not hard. You might not even notice the difference.

A couple of early beta testers found some tiny hiccups, which were
individually fixed, but nothing major. One tester had a problem with a
Powermax canister valve which I don't understand (it would not open
properly), but I do know that the crimping of the valves on those canisters
was 'variable' as the supplier was changed. A slightly longer pin solved
that for him.

A couple of almost invisible cosmetic changes were implemented when I had
the chance. Here's the burner:
5593: Winter stove, batch 4, burning

More user photos of the stove in use in the field (especially in the snow) would be appreciated.

Cheers

E J
(mountainwalker) - MLife

Locale: SF Bay Area & New England
A beautiful sight; Photo of folded stove on 01/02/2014 11:43:06 MST Print View

Roger, best wishes for the New Year.

That's a beautiful sight...

Could you post a picture of the 300T and 116T burner stoves compactly folded up? Or just the 300T if that's the only one you'll be making going forward.

Edited by mountainwalker on 01/02/2014 11:45:13 MST.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: A beautiful sight; Photo of folded stove on 01/02/2014 21:53:03 MST Print View

Hi EJ

5607: my stove curled up inside a pot

OK, herewith a photo of the stove folded up inside an MSR Titan 1.5 L pot - our normal dinner pot for most walks. I usually get a lot of other stuff in with the stove. In addition, my folding windshield is inside the pot along with some rather solid Ti mini-stakes for holding the stove down. I think the stakes are a bit of an overkill, but the weight is negligible.

Then I thought 'how about a stove comparison'? So herewith for that too.
5603: several stoves compared to mine

On the left we have an MSR XGK with a small (white gas) fuel bottle, 429 g / 15.1 oz with no fuel in bottle

In the middle we have a Primus Eta Power with integral windshield and optional pot, with a standard 230 g screw-thread canister, 375 g / 13.2 oz plus canister but without the pot shown here

On the right at the back we have an MSR Reactor stove plus pot, with a standard 230 g screw-thread canister, 571 g / 20.1 oz with special pot, plus canister extra

Finally, front right hand corner, we have my stove with a small Powermax canister, 85 g (3.0 oz) plus about 68 g for the empty canister.

Cheers

Billy Ray
(rosyfinch) - M

Locale: the mountains
Inverted canister fuel use on 01/24/2014 20:28:50 MST Print View

I have a Roger Beta Stove.

So I've read the directions and played around with it at about 20F.

I have a question. Not about the stove itself, but about what happens inside the canister when using an inverted canister stove.

First, Roger's directions recommend using the canister upright for 30 seconds or a minute to prime the stove... to get the warming chamber warm enough so that the liquid fuel easily vaporizes when the canister is inverted. Question: If the typical canister contains only 20% Propane, will this priming cause you to run out of propane (and thus priming ability) before running out of butane??? Obviously, if you only primed one or twice or thrice during the life of the canister (cooking for long times inverted) this would not likely be a problem. But I'm only boiling 8 oz of water in the morning and maybe 12 oz of water in the evening. That's a high proportion of prime time to cook time (even if you cook while priming) so I fear I will run out of propane and thus the canister will be useless at cold temps before it is empty.

Second Question:
After the canister is primed and inverted, does the stove burn equal amounts or equal proportions of butane and propane? I'm thinking if one of the two is heavier/denser than the other it will settle to the bottom and more of that will burn.

Please enlighten me.

thanks,

Billy

Stuart R
(Scunnered) - F

Locale: Scotland
Re: Inverted canister fuel use on 01/25/2014 02:27:31 MST Print View

Billy

1. If your canister contains 20-30% propane, then when you are priming the gas coming out will be 50-60% propane, so the answer is yes, if you do a lot of priming and not much cooking then the canister will become less effective at cold temperature as the contents are used up. I don't think it will be useless tho'

2. The liquid propane and butane mix pretty well, so if the mix is 20% propane then that is what will come out when inverted.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Inverted canister fuel use on 01/25/2014 03:19:16 MST Print View

Hi Billy

As Stuart said, if you do too much priming the canister will get low on propane.

However, if you switch to a filter disk under the jet, have the stove just a little warm before starting (body heat?), and start with a very low flame, there is little reason why you can't do the prinming thing with an inverted canister. If you are using a Powermax canister that is what you will be doing anyhow.

Filter Disk:
A recent upgrade. Cut out a 6 mm diameter circle of filter paper from either lab filter paper (I had lots left over) or use a paper coffee filter instead. You may find some sort of paper punch will give you the right size disk.
Remove jet, remove any tissue paper from inside. Check the jet is clear.
Insert filter disk into socket/hole and push down to near the bottom. It doesn't have to go all the way. It should NOT be floating loose: that would be too small.
Replace jet with just a little tightening.

It seems to me, from my testing, that this works a whole lot better than the tissue paper. It seems to catch and delay small drops of liquid fuel so they vaporise before reaching the jet. Well, works for me. Yes, this is included in the latest version of the Instructions.

I am making yet another batch of stoves, but my CNC is STILL playing up. I think I will have to replace most of the older electronics - all the motor drives. This will delay me a little, but it WILL be done!

Cheers

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Inverted canister fuel use on 01/25/2014 08:06:25 MST Print View

isobutane boils at 8 to 16 F - I don't know why there is a range given rather than a specific temperature

You said you were at 20 F, so it doesn't matter if there is less propane in the mix.

Gary Dunckel
(Zia-Grill-Guy) - MLife

Locale: Boulder
re: Isobutane vapor temperature range on 01/25/2014 08:29:17 MST Print View

"isobutane boils at 8 to 16 F - I don't know why there is a range given rather than a specific temperature"

Jerry, since the vaporization temperature is lowered when the altitude increases, maybe that's why they state a range?

Billy Ray
(rosyfinch) - M

Locale: the mountains
Re: Re: Inverted canister fuel use on 01/25/2014 08:31:53 MST Print View

Thanks Roger and Stuart, very helpful answers.
Jerry, I have played around with the stove at 20F just because that's the lowest temps I've had to work with on my deck lately; not because that is the only temp at which I expect to use the stove.

Roger, another question:
I would like to use a windscreen around the stove and pot fairly tight around the pot in cold temps. Will the heat inside the windscreen harm the flexible fuel feeder tube?

thanks,
Billy

Billy Ray
(rosyfinch) - M

Locale: the mountains
Re: Re: Re: Inverted canister fuel use on 01/25/2014 08:40:05 MST Print View

Roger... also...
In your instructions sheet you suggest that it's and option to start cooking/put the pot on the stove while priming.

I would add that placing the pot and windscreen actually helps to shorten the needed priming time because having the pot on top of the flame (and the windscreen in place) shunts more heat out to the aluminum plate that transfers heat to the pre-heat chamber and thus warms the chamber faster and allows sputter free inversion of the canister sooner.

does that sound right?

Billy

Billy Ray
(rosyfinch) - M

Locale: the mountains
Re: Re: Re: Re: Inverted canister fuel use on 01/25/2014 08:57:59 MST Print View

Roger,

How about using a bic lighter to warm the heat transfer plate and/or the pre-heat chamber in order to shorten or eliminate the priming time?

thanks,

Billy

Kevin Buggie
(kbuggie) - M

Locale: NW New Mexico
pre-heating designs on 01/25/2014 09:40:57 MST Print View

Great question, Billy. I've been waiting for some beta testing reports regarding how efficient (priming time needed to avoid inverted flare-up) the heating-shunt design is compared to the 'traditional' through-the-flame pre-heating tube on other invert canister stoves (windpro, etc)

For comparison, my Optimus Vega with the preheat tube has never flared or sputtered and I flip the canister within a second or two of lighting the stove in upright mode (basically the time it takes to put the bic lighter down and reach over to invert the canister).

The following pic shows the Vega in use at 10f, with preheat tube visible in the flame.

Vega invert

So is a 3 oz weight savings with the Caffin stove worth the compromise in priming/propane conservation performance? I'm thinking mostly about this in the context of alpine use where flaring in a tent vestibule, and preservation of gas mix ratio are of high importance compared to regular 3-season hiking conditions.

Douglas Frick
(Otter) - MLife

Locale: Wyoming
re: pre-heating designs on 01/25/2014 15:34:04 MST Print View

> So is a 3 oz weight savings with the Caffin stove worth the compromise in priming/propane conservation performance?


I haven't noticed any compromise. The only time I experienced flaring was when the Caffin stove and canister were at -25F and I immediately inverted the canister after lighting, before placing the pot on the stove. (Producing and evaluating flaring was the point of that test, documented earlier in this thread.) By the time I reached out and grabbed the pot and brushed the snow off, there wasn't enough flaring to stop me from putting it on the stove with my bare hand, and it settled down quickly after that. The other stoves (Coleman Exponent Xtreme, MSR Whisperlite Universal) that I tested under the same conditions also flared until their pre-heat loops warmed. All three stoves seemed to take a 'reasonable' amount of time to heat up, considering the test conditions.

My normal practice with the Caffin and MSR stoves is to take several seconds to set down the lighter, put the pot on the stove, and adjust the flame before inverting the canister. This ensures the rotation of the canister doesn't flip the stove. The process takes the same amount of time for either stove. I'm in no hurry here because I'm cooking with fire near my tarp and quilt and wearing gloves--no flaring allowed. It takes the Caffin stove about as long to warm up as the MSR, so I don't find there to be a priming penalty. I have enough experience now with the Caffin stove that I don't add a priming delay before inverting the canister; it always seems to be 'warm enough' by the time I get to that point.

Since I also use best practices to maintain a 'warm' canister before I start (unlike in the above test), I always have a reasonable gas mix pressurizing the canister. Propane conservation just isn't an issue.


Added: a friend of mine has an Optimus Vega. That's a very nice little stove, way lighter and cheaper than the MSR, and it performs well. I've been recommending it.

Edited by Otter on 01/25/2014 15:48:59 MST.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: re: Isobutane vapor temperature range on 01/25/2014 16:05:12 MST Print View

The official boiling point of iso-butane is -11.7 C (10.9 F), at sea level. Yes, it will fall with altitude.

Cheers

Edited by rcaffin on 01/25/2014 16:23:58 MST.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Re: re: Isobutane vapor temperature range on 01/25/2014 16:09:08 MST Print View

that's weird, wikipedia says 8 to 16 F.

normally they give a range for something like gasoline which composition can vary

I guess wikipedia isn't perfect, you get what you pay for?

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Temperature rating for hose on 01/25/2014 16:15:29 MST Print View

Hi Billy

> I would like to use a windscreen around the stove and pot fairly tight around the pot
> in cold temps. Will the heat inside the windscreen harm the flexible fuel feeder tube?
From page 20 of the Instructions:
'Both the Viton O-rings and the PFA hose can handle over 230 C (446 F). The rest of the stove body is metal.'
So if you can get the stove parts inside the windscreen up to 230 C, then there will be damage done. However, your chances of doing this are kinda slim!

In general, I would say that the stove parts inside the windscreen are unlikely to exceed 100 C in practical field use. If things do get start to get near 'sizzle-hot' then you should open the windscreen up a bit. I have never had any problems there.

In the snow I am happy to let the canister cop a little radiation from the stove, through the gap in the windscreen. Not a lot: just enough to take the chill off the canister. The plastics used on the canister connector should have no problems up to 40 C, which is the limit of comfort for fingers, but do try to keep all the canister end of the hose down to luke-warm.

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: Re: Inverted canister fuel use on 01/25/2014 16:16:42 MST Print View

Hi Billy

> I would add that placing the pot and windscreen actually helps to shorten the needed
> priming time
Exactly!

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
re Bic lighter on 01/25/2014 16:18:48 MST Print View

> How about using a bic lighter to warm the heat transfer plate and/or the pre-heat
> chamber in order to shorten or eliminate the priming time?
That certainly works to warm the heat shunt ('plate'), but it is not essential.

I have been using the same Bic lighter for maybe 6+ years. I will probably wear the flint out first!

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: re: pre-heating designs on 01/25/2014 16:22:58 MST Print View

Hi Douglas

> My normal practice with the Caffin and MSR stoves is to take several seconds to set
> down the lighter, put the pot on the stove, and adjust the flame before inverting the
> canister. This ensures the rotation of the canister doesn't flip the stove. ... ...
> I have enough experience now with the Caffin stove that I don't add a priming delay
> before inverting the canister; it always seems to be 'warm enough' by the time I get
> to that point.
Which is what I normally do myself. Good to have independant confirmation of this.

> I also use best practices to maintain a 'warm' canister before I start
Always a good trick!

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: re: Isobutane vapor temperature range on 01/25/2014 16:28:15 MST Print View

> that's weird, wikipedia says 8 to 16 F.
> normally they give a range for something like gasoline which composition can vary
> I guess wikipedia isn't perfect, you get what you pay for?
I have no idea where the author of the Wikipedia entry got his data from. I prefer to use technical reference sites for technical data - for that reason.

Gasoline does have a very variable composition. Commercial supplies of iso-butane will also turn out to be rather variable in composition, and that will influence the BP of the mixture.

Cheers

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Re: re: pre-heating designs on 01/25/2014 16:34:46 MST Print View

You know, what some stoves like this might need is a flame-based canister warmer. Imagine this. Imagine a tiny-size butane cigarette lighter that you store in your pocket for warmth. When you are almost ready to light the stove, you slip the lighter into a little clamp/holder that positions the lighter into a place at the middle of the base of the canister. You light the lighter and let it burn for a minute or two. Meanwhile, you turn the canister valve and light the stove. The warmth from the lighter would last for only a minute or two, until there is some feedback heat from the main burner, and then the lighter would be returned to the warm pocket.

In the old days, we used to do something like this using a small candle flame. As long as the flame hits a good place in the broad surface of metal, it seemed to work well for temperatures around 0*F.

--B.G.--

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
re: Isobutane vapor temperature range on 01/25/2014 16:49:00 MST Print View

just poking around trying to understand why they have a temperature range

I noticed that the refrigerant R600A is isobutane

on ebay, lot of 12 containers of 420 g costs $95 = about $4 per 210g (8 ounce) typical size for stoves. Plus shipping? A little cheaper than normal but not enough.

I wonder if you can buy a big container of R600A cheaper and use it to refill regular containers... Like from a refrigeration supply place?

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: re: pre-heating designs on 01/25/2014 17:22:33 MST Print View

Hi Bob

I am sure you could use a 'flame-based canister warmer', but I could not in all honesty recommend it. To be sure, experienced stove users might have no problems at all, but can you imagine what novices might do with the idea???? Terrifying!

Cheers

Dan Durston
(dandydan) - M

Locale: Cascadia
Other Fuels on 01/25/2014 17:33:59 MST Print View

This is probably a dumb question, but it theoretically possible to also use this stove with white gas or kerosene like MSR's WhisperLite Universal? I'd love to have this option.

Obviously an adapter would be needed, but are there are other hurdles?

Billy Ray
(rosyfinch) - M

Locale: the mountains
Re: Re: Re: Re: re: pre-heating designs on 01/25/2014 17:43:49 MST Print View

" I also use best practices to maintain a 'warm' canister before I start "

Glad you guys all agree on the above statement. But how about tell me what you mean specifically by that. (I have my own ideas, but have now idea what yours are on this)

Billy

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Re: Re: Re: Re: re: pre-heating designs on 01/25/2014 18:02:17 MST Print View

Typically, the coldest/worst time to have to light a cold stove is first thing in the morning, so you have been camped overnight there. You can sleep with a canister inside your sleeping bag, so right away that canister is going to be just below body skin temperature. If you take it out and leave it in cold air for too long, then it goes to hell again. Getting it lit and then letting some flame heat feedback to the canister keeps it going.

Putting a canister inside an insulator during operation may not get good results, because the evaporation cooling of the canister will make it cold, but then the insulator may hold that cold in it. Putting the canister into a pan of water may help if the air temperature is below freezing. That water may have come from your water bottle, and it may have been inside the sleeping bag as well.

--B.G.--

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
R600a on 01/25/2014 18:17:00 MST Print View

Hi Jerry

Yes, one certainly could use R600a on a stove. It is a high-quality (ie fairly pure) isobutane. It is available in various places in anything from common pressure-pack cans to 300 kg tanks. MSR use this fuel in their isobutane canisters already, so I would argue that practical field experience says this fuel is quite safe.

The problems I can forsee with attempting to do this are:

1) The vendors sell this to refrigeration engineers, and require that the customer complete a safety training course first. After all, you are switching from a relatively non-inflammable freon refrigerant to a very inflammable butane!

2) You would need to find a safe adapter with (preferably) two valves to go from the R600a container to the canister used for the stove.

3) You would need to be able to control how much gas (liquid) you put into the canister to avoid over-filling it - which could lead to an explosion in hot weather if you fill to 100%.

4) All the canisters are rated for a single use, with refilling legally banned. My personal opinion here is that main reason for this is that the authorities are terrified of the idea of amateurs refilling a canister, and I can't blame them. A secondary reason could be the problems you would get with rusty canisters: they may not seal properly at the external O-ring.
That said, I note that you can legally buy the adapters in Japan, so maybe they don't have such a ban there.

Disclaimer: neither I nor BPL advocate refilling canisters, for obvious reasons.

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Other Fuels on 01/25/2014 18:22:20 MST Print View

> [is] it theoretically possible to also use this stove with white gas or kerosene
> like MSR's WhisperLite Universal?

In practical terms, no. The problem is that the boiling point of white gas is much higher than the feedback from the Heat Shunt can sustain at the stove body.

The Heat Shunt is sized to keep the stove body a bit above 0 C, which is fine for butane and propane, but white gas needs a temperature of over 150 C. Kero needs even higher temperatures.

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: Re: Re: re: pre-heating designs on 01/25/2014 18:24:22 MST Print View

> " I also use best practices to maintain a 'warm' canister before I start "
> tell me what you mean specifically by that.

See Bob's reply.

Cheers

Billy Ray
(rosyfinch) - M

Locale: the mountains
Re: Re: Re: Re: Re: Re: re: pre-heating designs on 01/25/2014 18:27:23 MST Print View

> " I also use best practices to maintain a 'warm' canister before I start "
> tell me what you mean specifically by that.

See Bob's reply.

And here I though you guys were into something I didn't know... throwing around them fancy terms like 'best practices'... gee...

Billy

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Re: Other Fuels on 01/25/2014 20:06:27 MST Print View

I think the tempertures needed could be reached with simply looping a piece of stainless tubing over the flame. Then we need to supply a dufferent jet, since the raw WG vapour wiold differ in density. I would guess that the valve would be OK. As far as initially feeding the fuel, some sort of pump would be needed. I belive that it starts adding a LOT of weight. The only thing that would survive, intact, would be the valve.

Yeah, it could be done. Feasability seems do dictate otherwise, though. Such a hacked up combination would undobtedly be approching the weight of the Simmerlite (~8oz.) It would likely suffer the same problems with simmering.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: Other Fuels on 01/26/2014 01:51:05 MST Print View

The purist would use Inconel; the pragmatist would use brass. Yep, some preheat tubes are brass. But a stove does not get as much use as a steam angine boiler.

Cheers
PS: YOU try machining Inconel. It's a nickel alloy.

USA Duane Hall
(hikerduane) - F

Locale: Extreme northern Sierra Nevada
Tiny screws on 01/27/2014 11:54:14 MST Print View

I noticed on this stove that it has some tiny screws in the plastic that is part of the piece that attaches to a canister. One stove had that part come off, the new owner had some issues getting it attached to the canister, maybe user error. He may have found a tiny screw driver to see if it could be screwed back on. A lot of plastic on the stove I noticed also at the GGG. Still in beta stage correct?
Duane

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Tiny screws on 01/27/2014 14:31:31 MST Print View

Hi Duane

Yes, still in beta test, but that means I am looking for what can go wrong, not for any major design changes. As I have shipped over 60 stoves now, with only a few problems reported and all fixed, I am fairly happy with the design.

Plastic: yes, good stuff. NO intentions AT ALL of changing the plastic to metal. That wouldn't work, for a start.

The tiny screws: yes, they are small. Yes, you need a small Philips head screw driver to handle them, IF you intend to disassemble the connector. Such screw drivers come in little kits for a few dollars. Other stoves also have tiny screws. The ones on watches are even smaller!

The 'Main Ring' on the connector which is held in place by two screws. Yes, this can come off, but it should only do so AFTER the screws have been removed. If it is ripped off accidentally the screw holes will be damaged. Gently, gently with the rotating Spider is the message. If this has happened to anyone (or to their stove), please contact me. I will help to fix the problem. There are ways.

Cheers

Hikin' Jim
(hikin_jim)

Locale: Los Angeles, CA, USA
PowerMax Canisters on 01/28/2014 23:28:15 MST Print View

As reported on the GGG photo thread, I had a bit of trouble getting a "Caffin stove" (is there a better name?) to work with PowerMax Canisters. It may have just been a time thing; I had very little time to experiment before the stove's owner needed to leave. I hooked it up to a threaded canister first, then a Camping Gaz canister. Took me a bit to figure out exactly how things went (I didn't have the benefit of instructions), leaving me little time to experiment with PowerMax. I did give it a good number of tries though.

There has been the suggestion that perhaps the canister I used was "not quite right", and I was asked if I might take some photos, which I have.

The top canister (marked with a "2") is the one I believe I used at the GGG. The second canister is shown for comparison. More on that in the second photo.


Here are our two canisters again, this time showing the connectors. The canister on the left is the one I used at the GGG.


It's possible that the connector on the canister on the left does not protrude as much as the canister on the right. The canister on the left is stamped with a manufacturing date from 2003. The canister on the right is stamped with a canister date from 2004.

HJ
Adventures in Stoving
Hikin Jim's Blog

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: PowerMax Canisters on 01/29/2014 00:33:30 MST Print View

Hi Jim

Odd, very odd. I would expect both of those canisters to work just fine.

Do you still have access to that stove, or does the owner have some Powermax canisters? I would like to ask for some photos of the stove in some VERY simple tests.

Could you get the owner to email me direct? Yeah, this is a beta test, but it should work OK. I WANT to know what the problem is!
roger@backpackinglight.com

Cheers

Hikin' Jim
(hikin_jim)

Locale: Los Angeles, CA, USA
Re: Re: PowerMax Canisters on 01/29/2014 10:21:20 MST Print View

Unfortunately, EJ, the owner of the stove, lives about 7 hours drive north of me. Now, I've very curious as to why I wasn't getting gas flow. The canister did work both before and after when I hooked it up to a Coleman Xtreme, so I know the canister was in working order.

I believe you and EJ have been in contact previously, yes? Perhaps he can run those tests for you. I believe he has some Powermax canisters.

HJ
Adventures In Stoving
Hikin' Jim's Blog

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: PowerMax Canisters on 01/29/2014 13:54:03 MST Print View

Hi Jim

OK, EJ and I will sort it out.
Such canisters work for me when tested over a number of stoves. May have been a 'learning' problem. Even so, I want to know about it.

Cheers

Billy Ray
(rosyfinch) - M

Locale: the mountains
Re: re: pre-heating designs on 02/01/2014 12:19:54 MST Print View

"I haven't noticed any compromise. The only time I experienced flaring was when the Caffin stove and canister were at -25F and I immediately inverted the canister after lighting, before placing the pot on the stove. (Producing and evaluating flaring was the point of that test, documented earlier in this thread.) By the time I reached out and grabbed the pot and brushed the snow off, there wasn't enough flaring to stop me from putting it on the stove with my bare hand, and it settled down quickly after that"

Douglas,
I wish I could say the same. I've had lots of flaring.. From 20F to -15F..
and in some cases it doesn't go away until I turn the canister back upright.

wondering if you pre-warmed the canister and/or the heat shunt?

Billy

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: re: pre-heating designs on 02/01/2014 13:27:33 MST Print View

Hi Billy

> I've had lots of flaring.. From 20F to -15F.
In that case maybe you should bend the heat shunt a little bit towards the flame. Maybe just 2 mm movement at the top. This will get heat down to the stove body a bit faster. I do mention in the Instructions that you may need to do a litte tuning on your stove.

Cheers

Billy Ray
(rosyfinch) - M

Locale: the mountains
Re: Re: Re: re: pre-heating designs on 02/01/2014 13:36:38 MST Print View

Hi Roger,
Yes, I had already bent the heat shunt to the point that it's a bit hard to get the one pot holder past it... so don't think I can bend it further.

Yes, I understand about the 'tuning'.
In addition to that this is my first inverted canister stove so there is a learning curve.

I'm actually wondering if maybe you put the tissue filter in there an maybe it is getting saturated with liquid fuel and thus inhibiting the flame (very weak after/during flaring).
I may open it up an see what if any filter in in there. If it's tissue, then I may try your filter recommendation.

I believe I am using quality canister fuel... Snow Peak and JetBoil... so I am assuming that clogging is not the issue.

billy

Billy Ray
(rosyfinch) - M

Locale: the mountains
flaring... clogged jet on 02/01/2014 14:50:35 MST Print View

Hi Roger,
so... pulled the jet... there was a little very light oily substance on the top of the jet... no light visible though it... got a hand lens and it is obvious that the jet is clogged... stuff so small it is hard to see, but looks like very very fine, gray metal shavings maybe... just packed in the jet hole... very few on the outside top of the jet so it must have been passing some..

that would explain the weak flame this morning when cold with lower pressure in the canister... and maybe at warmer room temp it may explain the very strong flame in that maybe the pressure coming from the canister at room temp was enough to blow those extremely find particles through the jet?

So my next question is WHERE do I find a copper wire small enough to clean the jet?
AND... do I have to know for sure that the wire is smaller than the 0.28mm jet hole before I go trying to push it through??? Any possibility that a copper wire will damage the jet hole?

Other things that concern me now:
If there are shavings (or whatever it is) inside the jet, there are likely shavings inside the jet holder, the fuel tube, and the spider connector. How do I clean all that???

AND where do these shavings come from???? The manufacturing process of the stove? Or the canister??? I'd like to avoid having this happen again... especially if I'm camped out in winter :(

thanks,
Billy

Billy Ray
(rosyfinch) - M

Locale: the mountains
Re: flaring... clogged jet on 02/01/2014 14:56:33 MST Print View

oh, and there was no tissue filter or any other filter..

billy

Douglas Frick
(Otter) - MLife

Locale: Wyoming
Re: flaring... clogged jet on 02/01/2014 18:16:24 MST Print View

>wondering if you pre-warmed the canister and/or the heat shunt?


No, as I detailed in my post, both canister and stove were at ambient temperature.

But from your subsequent posts, it seems you may have isolated the problem (I hope). I'm sure Roger will follow up with a comment about the clog, but I thought I'd add that I made a canister-gas jet cleaner from a single strand of copper wire from an old twisted-pair Ethernet cable (not telephone station cable; that's too thick). I doubt such a fine copper wire would hurt the jet, because it's smaller than the jet, and softer than the jet material. Roger specifically cautions against steel needles because they're too big, and probably harder.

I used that wire on my Coleman Xtreme. Not sure what got into its jet, but it sure ran a lot better once I cleaned it out.

Billy Ray
(rosyfinch) - M

Locale: the mountains
Re: Re: flaring... clogged jet on 02/01/2014 18:20:29 MST Print View

Hi Doug,
well, I've had the stove apart.. jet was clogged.
I managed to find a very small copper wire for the task.

Also, there was no filter. So I made one on Roger's suggestion out of coffee filter paper.
Stove runs better now, but only ran it for a minute.

Will try again tomorrow morning in the cold.

Billy

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: Re: re: pre-heating designs on 02/01/2014 19:06:06 MST Print View

> I believe I am using quality canister fuel... Snow Peak and JetBoil...
There is some suspicion about the Jetboil canisters. They may be rebadged Chinese. The Chinese ones I tested were AWFUL: instant blockage. Does the label have specs for the fuel percentages? Yes, the label may be significant.

Oily stuff on top of the jet? That's out of the canister fuel. I've seen it before. It collects all sorts of gunge. It suggests a Chinese canister. You should also clean the needle valve tip in that case.

> [filter] getting saturated with liquid fuel and thus inhibiting the flame
Very doubtful if we are talking about butane and propane. Liquids from dirty fuel might do this, but I suspect not.

The dirt at the jet? Not sure whether it is actual dirt from the canister or fine aluminium swarf from the stove body. The latter may have come from the jet socket - unfortunately.

Filter paper: seems to be working well for quite a few people. Thus beta testing.

Cheers

Edited by rcaffin on 02/01/2014 19:07:19 MST.

Billy Ray
(rosyfinch) - M

Locale: the mountains
Re: Re: Re: Re: Re: re: pre-heating designs on 02/01/2014 19:35:15 MST Print View

"instant blockage. Does the label have specs for the fuel percentages? Yes, the label may be significant."

No percentages on the JebBoil canister.

The 'oil at the top of the jet' was clear, very and very think and it did not look dirty. I even though it might be some of the silicone greese...

Needle Valve was clean...

Using a hand lens at least some of the stuff blocking the jet appeared to be very find silver colored flakes... could be aluminum from the thread cutting?
But there was also darker stuff that look more like dirt...

I guess it could be both canister contamination and from the thread cutting...

Any idea what the safest canister fuel is for being clean? The local REI sells MSR, JetBoil and SnowPeak... those are my choices.

Billy

Adam Kilpatrick
(oysters) - MLife

Locale: South Australia
Roger's stove on 02/17/2014 08:04:34 MST Print View

Just caught up on this article and thread. Really impressed Roger. If I was planning a lot of Tassie trips in the next few years (no, baby(s), I'm grounded) or snow trips soon I'd jump on one, but you should sell your beta's to those who can test in the cold for you.

Have you considered what your next stove project will be? It would be cool to see you apply yourself to the super efficiency equation for above freezing stoves. Overall system weight efficiency, I mean. Personally though I love the convenience and efficiency of upright canister stoves, I'm torn by the use of canisters and the whole partial canister issue. On long trips (eg cycle touring Europe) its not much of a problem, but for trips of just a few days where I might need less than half a canister, it screws with my head. So I think I'll personally stick to alcohol for now.

Billy Ray
(rosyfinch) - M

Locale: the mountains
Re: Roger's stove on 02/17/2014 09:14:32 MST Print View

Adam,
regarding the 'partial canister issue'
I weight my canisters. The weight before and after a trip divided by the number of days gives you a good idea of how many ounces or grams of fuel you need per day.
That will tell you how many days any of your partially used canisters will be good for.
It's not perfect, but allows one to use up at least some of the partial canister fuel.

Billy

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Re: Roger's stove on 02/17/2014 11:48:33 MST Print View

+1 to Billy

I sometimes have a number of partial canisters of various weights to choose from which can be a nuisance

I do some car camping so I eventually get all the partials used

If I do a lot of trips that use a little more than half a canister it's more of a problem. For me that's 5 nights, and I've done several 5 night trips recently, but eventually all the partials will get used.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: Re: Re: Re: re: pre-heating designs on 02/17/2014 13:46:53 MST Print View

Oh, the oil on the jet is liely to look clean. It is just a much higher hydrocarbon from unrefined gas.

> Using a hand lens at least some of the stuff blocking the jet appeared to be very
> find silver colored flakes... could be aluminum from the thread cutting?
> But there was also darker stuff that look more like dirt...
Yeah, I would say a bit of both.

> Any idea what the safest canister fuel is for being clean?
Depends on what is available. Have a close look at the canister for the 'Made in XXX' mark. Most of them do have this. If the canister says where it is made (Korea, France, anywhere but China) then it is probably OK. If it says China or does not say, I would be suspicious.

Interesting note: the Powermax canisters do not say where they are made, but they ARE clean.

Cheers

Billy Ray
(rosyfinch) - M

Locale: the mountains
Re: Re: Re: Re: Re: Re: Re: re: pre-heating designs on 02/17/2014 14:19:30 MST Print View

Roger... all my canisters say Made in Korea.

So it would seem that the blockage was from not enough cleaning of the stove on your end before shipping.

In any event I have not had another blockage since pulling it apart and cleaning the jet... (and using the same canisters).... yet.

I did try your suggested coffee filter paper as a filter. But I don't think it works very well. Looked at it after using the coffee filter circle for a while and it looks to me like the pressure of the fuel entering at one side of the jet socket just pushes past the edge of the coffee filter paper circle.

What was wrong with the toilet paper filter anyway? Why did you suggest go go away from that?

Billy