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Roll-up stove
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Colin Krusor
(ckrusor) - M

Locale: Northwest US
Roll-up stove on 03/13/2011 14:57:53 MDT Print View

I like using little wood stoves, but they are usually a bit heavier than I'd like (4-6 ounces) and some are a little bulky.

The body is 0.005" 15-3-3-3 titanium foil, the ribs and the triangular piece of the pot stand are 0.016" 6Al-4V titanium sheet, the pot stand rods are 3/32" 6Al-4V titanium shepherds-hook-like tent stakes, and the screen is 309 stainless steel. The stove body is 6" high and 4.5" in diameter. With the pot stand the pot elevation is about 8 inches. It fits neatly into a BPL firelite 900 pot (but only the screen is meant to be stored that way). The whole thing (with the stand) weighs 2.6 ounces (71 grams).

The little tabs on the sides, near the bottom, are for lifting/moving the stove while it's hot. The screen on the bottom is shaped like a bundt pan (like the surface of the lower half of a donut), and the openings in the screen are small (maybe about 15 wires per inch). The fine screen retains the fuel (even dry grass doesn't tend to fall through), but the bundt-like shape keeps the screen from becoming occluded (things slide to the bottom of the donut). Even with a lot of cinder at the bottom, most of the screen remains clear of debris.

I also put a big mouth-like opening on one side of the stove, with a "latching" door. With other commercially-made wood stoves I've used, I found it difficult (mostly due to lack of skill on my part) to get a good fire going with damp fuel when I could only light it from the top. The side opening on this stove makes it much easier for me to burn suboptimal fuel (wet leaves, etc.), and I end up needing less carried tinder (vaseline+cotton, dryer lint, etc.). I just use this opening for fire starting. Once it's going I feed it from the top. The door has a little bit of ceramic-fiber twine attached, and it can be opened and closed when the stove is hot.

The whole thing rolls up, the screen fits inside the pot, and the ribs are flat and pack easily between other things. Input is welcome.

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. Callahan
(AeroNautiCal)

Locale: Stoke Newington, London, UK.
Outstanding design and construction! on 03/13/2011 16:58:04 MDT Print View

That is absolutely outstanding!

Superb craftsmanship.

A work of art.

As you can see, I really like your excellent stove. (o:

Franco Darioli
(Franco) - M

Locale: Melbourne
Roll-up stove on 03/13/2011 17:08:45 MDT Print View

Amazing. Well done.
That is a work of art...
Franco

Michael Crosby
(djjmikie) - MLife

Locale: Ky
Re: "Roll-up stove" on 03/13/2011 17:27:16 MDT Print View

Tinkering at it's best.

Amazing little stove.

Bravo!!

seth t
(diggity) - F
oo on 03/13/2011 17:40:07 MDT Print View

oo

Edited by diggity on 04/06/2012 20:56:16 MDT.

a b
(Ice-axe)
Brilliant.. now patent it.. quickly! on 03/13/2011 17:43:03 MDT Print View

That is bloody brilliant Colin! I am a big fan of wood stoves and fire in general. I sure hope you are planning to manufacture and market this stove. I would buy one!
Come to think of it.. put me down for one of those as soon as you get production rolling!

Edited by Ice-axe on 03/13/2011 18:09:30 MDT.

Paul Wozniak
(PaulW)

Locale: Midwest
my back hurts... on 03/13/2011 17:52:58 MDT Print View

from picking my jaw up off the floor! It looks fully functional, clever, light, compact and beautiful workmanship. Wow!

Hikin' Jim
(hikin_jim) - MLife

Locale: Orange County, CA, USA
Re: Roll-up stove on 03/13/2011 19:34:55 MDT Print View

Wow. Impressive workmanship.

HJ

John Nausieda
(Meander) - MLife

Locale: PNW
"Roll-up stove' on 03/13/2011 19:53:47 MDT Print View

I HATE to be like this, but recent Kettle events here at BPL( the kettle Fiasco} suggest to me that you may want to take these pictures down-Is that technically possible?Ask support at BPL. You are hitting a bulls-eye on many targets, Weight. Storage, Fire feeding, re-use of stakes. Don't provide a template or measurements. Take orders if you want but I would look into a patent or sell the design with legal help. Personally this looks as good if not better than the Caldera Cone. I myself want a larger size but that should be easy. Please look at the paper trail on the kettles. Your best defense is Offense.

Edited by Meander on 03/13/2011 19:54:39 MDT.

John Donewar
(Newton) - MLife

Locale: Southeastern Louisiana
Re: Roll-up stove on 03/13/2011 20:40:20 MDT Print View

Colin,

Origami meets titanium foil on Christmas morning! Put tab A in slot B while holding mouth just so. LOL ;-)

Seriously you have just made something new, different and light! I was just beginning to think that there was not much new that could be done to lighten our loads. Then you pop up with this gem of a roll up stove.

Get a copyright, patent or whatever it takes to protect your rights to this beauty.

You just struck gold!

Party On,

Newton

Dave Heiss
(DaveHeiss) - M

Locale: Pacific Northwest
roll up stove on 03/13/2011 21:19:21 MDT Print View

Holy cow. That stove is like nothing I've ever seen. Your design and production skills are off the charts. Well done!

tyler marlow
(like.sisyphus)

Locale: UTAH
1 piece on 03/14/2011 00:29:24 MDT Print View

First off, wow! This thing is incredible.

I'll second, third, fourth the others and say I'd buy one in a heartbeat if the price was right!

Although this is contrary to the reason you made this beautiful piece in the first place...I would actually like to see one of these made as one piece with a sort of hinged door for the feeder opening.

Very impressive, keep up the good work! If you do decide to sell these i think you'll have a winner.

Tim Marshall
(MarshLaw303) - MLife

Locale: Minnesota
Re: 1 piece on 03/14/2011 06:45:12 MDT Print View

will trade quilt for stove!!

-Tim

Mike M
(mtwarden) - MLife

Locale: Montana
waiting list on 03/14/2011 07:56:31 MDT Print View

put me on the waiting/interested list as well- that's a dandy!

Colin Krusor
(ckrusor) - M

Locale: Northwest US
Stove on 03/14/2011 09:22:02 MDT Print View

Thanks for all of the accolades. I actually first began working on this stove about two years ago, but time constraints forced me to put it on hold for a while. I don't think commercialization of this stove will be feasible for me while I'm in graduate school. If I had ready access to a laser cutting shop, and software to design the cuts, I might consider producing a limited run just to provide for interested people on BPL, but at present I don't have the time or the capital to invest in it.

I do plan to make a few modified versions over the summer, though. This version uses 0.005" 15-3-3-3 Ti foil for the body, but I think 0.003" CP4 Ti foil (which Steve Evans sells on his site) would probably be sufficiently stiff. A copy of this stove using 0.003" CP4 foil would probably weigh a hair over two ounces. If the stainless steel screen on the bottom were then replaced with a titanium screen, the weight should come down to the 1.8 oz range, I would guess.

15-3-3-3 foil used in this version becomes a bit brittle after the beta transition (which occurs at the first exposure to wood fire temps). I noticed a small crack in the foil at one of the edges. The CP4 foil is softer and should be less prone to embrittlement, but it might be prone to deformation during fabrication (which, for me, involves stout scissors, a dremel, and a punch).

Tyler, I'm not sure what you mean by one piece. The door and the body are a single sheet of foil. Do you mean a seamless cylinder that doesn't roll up?

Tim, I'm tempted to take you up on your offer. This little stove is nowhere near the value of your quilts, though. Maybe I could provide the materials (fabric and down) and a stove. It will have to wait a bit in any case. I won't have time to make another stove right away. I'll keep in touch with you.

Thanks again for the feedback. Ideas and input are welcome.

Edited by ckrusor on 03/14/2011 09:55:32 MDT.

Mike S
(MikeyLXT) - F

Locale: Maryland
Re: Stove on 03/14/2011 09:59:26 MDT Print View

Drawing up a pattern for your stove would be incredibly simple if you provided someone with your current design. Anyone with CAD software and a couple hours of experience could easily do that...if your college has an engineering department any of those students could probably do it for a small fee. Hell if you sent me the stove I could do the CAD drawings for a fee and then it is just importing that file to someone with a laser cutter.

This really is a great design. Time/money may be a bit of a constraint now but you see how impressed the people are here. You could always patent it now and then sit on the design for a year. When you have more time you could start a side business and see how it sells.

Edited by MikeyLXT on 03/14/2011 17:01:17 MDT.

tyler marlow
(like.sisyphus)

Locale: UTAH
One Piece on 03/14/2011 11:14:59 MDT Print View

Sorry Colin, I should have been a little more clear.

You assumed correctly though, I was thinking along the lines of a non-collapsible, all in one piece (minus the potstand)

Tim Marshall
(MarshLaw303) - MLife

Locale: Minnesota
Re: One Piece on 03/14/2011 12:23:02 MDT Print View

if you want to talk about a trade shoot me an e-mail. I am sure an Epiphany-K might be worth a few stoves but we could at least kick some ideas around.

-Tim

Jake Palmer
(jakep_82) - MLife

Locale: Pacific Northwest
Re: Stove on 03/14/2011 12:57:41 MDT Print View

I'm a buyer for a manufacturing company and we have a laser out in the shop. I can probably get these cut fairly inexpensively. If you're interested I can inquire, but I would need a CAD drawing to get it properly quoted.

John Donewar
(Newton) - MLife

Locale: Southeastern Louisiana
Re: Re: Stove on 03/14/2011 13:22:10 MDT Print View

@Colin,

I count five people on just this thread alone who are interested in purchasing your stove.

"I don't think commercialization of this stove will be feasible for me while I'm in graduate school. If I had ready access to a laser cutting shop, and software to design the cuts, I might consider producing a limited run just to provide for interested people on BPL, but at present I don't have the time or the capital to invest in it."

Mike wants to help with the CAD drawing.

Jake seems willing to assist you with getting them cut out.

Five of us interested people on BPL want one or more.

Grad students need funds. This could be a viable source of income for you.

Think about producing the limited run. You might like the results.

And yes I am very interested. ;-)

Good luck.

Party On,

Newton

Michael Crosby
(djjmikie) - MLife

Locale: Ky
Re: "Roll-up stove" on 03/14/2011 13:56:04 MDT Print View

Count me in for one.

Troy Ammons
(tammons) - F - MLife
Roll-up Stove on 03/14/2011 14:00:28 MDT Print View

Wow, that's a nice piece of craftsmanship.

Jake Palmer
(jakep_82) - MLife

Locale: Pacific Northwest
Re: Roll-up Stove on 03/14/2011 14:20:49 MDT Print View

After a little research I've found that laser cutting titanium is rather difficult and requires argon. We wouldn't be able to cut it here, but having it cut on a water jet should be possible. If you decide to pursue this I would recommend looking for a local shop with a water jet.

Dustin Snyder
(DustinTSnyder)

Locale: Southeast
"Roll-up stove" on 03/14/2011 14:46:56 MDT Print View

That is sweet! I would like one also if you do decide to make some more.

Sam Duckworth
(SamD) - F
Roll Up Stove on 03/14/2011 14:48:15 MDT Print View

Count me in as an interested one!
Put my name on the Buy list!

Awesome! As others have said PROTECT YOUR INVENTION!

John Nausieda
(Meander) - MLife

Locale: PNW
"roll up stove" on 03/14/2011 14:57:40 MDT Print View

Count me in as interested. Can't a standard punch press handle this since it is so thin? I imagine it would wear faster than one punching steel or aluminum but I'd look into it first . And you should ask Roger Caffin what he thinks would work. I'd still take those photos down . Good luck.

Rob Bouchard
(MrZsasz) - M
I'm in on 03/14/2011 16:51:29 MDT Print View

Not sure what number I am but count me in as well if you make these up. It's just so dang pretty....

Michael Schwartz
(greenwalk) - MLife

Locale: PA & Ireland
Roll-up stove on 03/14/2011 17:17:43 MDT Print View

Bravo! Count me in too. M

. Callahan
(AeroNautiCal)

Locale: Stoke Newington, London, UK.
Count me in! on 03/14/2011 17:27:06 MDT Print View

I'd be more than happy to buy at least one of these stoves, more than happy to pay in advance to help defray your set up costs too.

Please protect your design because YOU created this gem and it, along with your ingenuity and skill certainly merits protection, as well as recognition!

Chris Benson
(roguenode) - F

Locale: Boulder
sweet stove on 03/14/2011 18:52:01 MDT Print View

+1 on Seth's mention of steampunk. Has a bit of that design aesthetic to me.

Add me as another potential customer if you're considering the production. Regardless of what you do, I agree, you should take a bit of time to protect the design.

Really nice work!

Edited by roguenode on 03/14/2011 18:52:40 MDT.

tyler marlow
(like.sisyphus)

Locale: UTAH
Water cutting on 03/14/2011 19:00:12 MDT Print View

You may want to contact Steve Evans of Suluk 46 about water cutting.

On his site he has a list of the services he provides and I know he has done some water cutting with his titanium snow stakes...you can probably work something out.

If anything you could have someone else make them and just get a % as the creator.


Or you may want to stay out of the production side of it and just enjoy tinkering without all of us gear obsessed cretins bothering you :)

Jared Dilg
(Village) - MLife

Locale: Texas
Re: "roll up stove" on 03/14/2011 20:22:20 MDT Print View

Colin, this is really cool!

I'd echo what John Nausieda said and suggest you hold your designs tight. I had only learned about 3 weeks ago of Devin Montgomery's kettle project. Though not on the market for one, I'm really rooting for him to succeed! It's very cool to see a grad student bootstrap a project like that and take it to market. I'd love to see you get some recognition for your design.

Again, really sweet!

Backpack Jack
(jumpbackjack) - F - M

Locale: Armpit of California
Re: "roll up stove" on 03/14/2011 20:31:20 MDT Print View

Count me in for at least one if you build them.

Chris Hanson
(ChrisHanson) - F

Locale: Eastern Wyoming
Re: Roll-Up Stove on 03/14/2011 21:02:36 MDT Print View

Not sure if you'd need the services of a laser/engraver but I have one. You could put your name, logo, etc on it. Works great on anodized aluminum but the mark would disappear from any place that get hot enough to "color" it...

Chris Chatman
(ChrisChatman) - MLife

Locale: Mid-Atlantic
I'm in on 03/14/2011 21:11:14 MDT Print View

Count me as another interested buyer!

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: "roll up stove" on 03/15/2011 03:19:42 MDT Print View

> Can't a standard punch press handle this since it is so thin?
Punching really thin but hard sheet metal is actually a right pain. The tolerances on the punch and die have to be much tighter, which makes them rather expensive.

If you are making hundreds, consider laser or water jet cutting.
If you are making a small number, buy a carbide scribe (not a steel one) and some industrial/production quality tin snips. Not your local hardware store.
Then make up a template out of 2 mm aluminium sheet and mark the bits out one by one. Cut them out with the tin snips.
Ah, but the slots ... HARDER! Steel sheet templates, clamp on both sides, drill and Dremel.

If you are mad keen, make up a solid steel template, stack 20 layers of Ti foil together, bolt down really firmly and CNC with a carbide cutter. The cheap Chinese carbide won't hack it: you need German or Swedish carbide (HRC55+). (He speaks with experience ...)

Photos - too late. Once published, that's it.

Cheers

Richard Brownkatz
(Rbrownkatz) - F

Locale: Southeast
Genius on 03/15/2011 09:10:19 MDT Print View

"...work of art is the only way to describe."

+1

"You definitely need to patent."

+1

Count me as another interested buyer!

+1

"...more than happy to pay in advance to help defray your set up costs too."

+1

Genius. Absolute genius.

Eugene Smith
(Eugeneius) - MLife

Locale: Nuevo Mexico
"Roll-up Stove" on 03/15/2011 09:32:37 MDT Print View

Very sharp.

Rob Wolfenden
(wolverine) - F

Locale: North East
Roll-up stove on 03/15/2011 10:16:06 MDT Print View

Awesome job!!!!

Derek Goffin
(Derekoak)

Locale: North of England
Roll-up stove on 03/15/2011 11:02:01 MDT Print View

Very pretty and in this case therefore right.
Get Steve to give advice on water cutting.
Tiny quibbles but I guess assembly with all those slots on the top top and bottom disks is a bit awkward and a bit of distortion and it would get worse. The top disk at least doesn't carry any weight it just gets knocked, would less slots still keep it in shape? or even just the main 3 slots? Can you assemble the bottom and lock it then assemble the top? If the top disk is too fragile without the slots could it be pressed/formed into a stiffer shape?

Colin Krusor
(ckrusor) - M

Locale: Northwest US
Stove on 03/15/2011 13:20:21 MDT Print View

Thanks again for all of the feedback. I wasn't prepared, I guess, for so enthusiastic a response. In light of the arguments many of you have made for intellectual property protection and small-scale production, I have reconsidered my intitial position a bit.

I sent in a provisional application for a utility patent this morning (which is limited in legal fortitude in that it does not include a detailed report on prior patents, but establishes a first claim to a described "novelty"), and this entitles me to one year of protection in which to complete and submit the more rigorous full patent application (with all of the substantial associated fees). The provisional patent application is essentially like buying an option. It creates a paper trail and guarantees that I have first dibs on obtaining a full patent for one year.

Also, I found a Sketchup plugin that will allow me to export .skp files as .dxf CAD files, which would be required for laser-cutting. I've contacted several laser-cutting shops here in the Central Valley and in the Bay Area (CA), and I'll try to compute per-unit materials costs (including cutting) some time this week.

However, I'm not promising anything. I'd rather not take any money beforehand, and, at this point, I'm not committing to any delivery date or update schedule. My principal obligation is graduate school, and this project will have to take a backseat to that. I appreciate all of the interest in this stove, and I'll do my best to find a way to produce a batch that I can distribute to the readers of this forum, but it may be a slow-moving project.

Also, I'd like to mention some of the shortcomings of this design before anyone vows to obtain one. I'm really pleased with how it turned out, on the whole, but I just want everyone to be familiar with the imperfections.

Assembly isn't confusing or complicated, but it is a little tedious, especially the first few times one tries it. Once you're accustomed to it, it's not difficult. It can be slow going with cold fingers, though. It's like setting up a tiny model of a tent.

Also, as I mentioned in an earlier post, the 15-3-3-3 alloy foil becomes brittle after the beta transition, and can crack at the edges. The pictured prototype has a small crack. This isn't likely to affect the function, but you might find it unsightly, and it creates a new sharp edge. There may not be a way to remedy this.

Lastly, the screen is a store-bought stainless steel screen, in a circular stainless steel frame. The frame is just pressed onto the edges of the wire, and, over time, some of the wires will inevitably slip out, I think. So, keep in mind that the screen might need occasional replacement.

As long as the limitations are clear, I'm interested in hearing design feedback. Does everyone who expressed an interest see nothing about the first version that could be improved? Any ideas about the aforementioned shortcomings? I'm personally interested in trying 0.003" CP4 foil, but I won't be using it on versions that I might hypothetically distribute, because I'm afraid the thinner and softer foil might warp or bulge when red-hot. I plan to replace the ceramic-fiber twine on the door with a wire, for durability, and I plan to shorten the "crook" part of the tent stakes and enlarge the triangle in the pot stand (to make the stakes more functional as stakes). Any other ideas? What would you like to see if you were to receive one, hypothetically?

Derek, I think the top ring could have fewer tabs, and the upper part of the foil could have fewer slots. The main three might be enough. I doubt that it will be possible, with a good fit, to insert the top ring during assembly with the bottom ring already "locked in", even with a reduced number of tabs/slots. This would require a looser fit, which, for stability, I'd rather avoid. It has to be assembled bottom-ring first with the body tabs in the slots, then the screen, then the top ring, then cinching up, then the pot stand.

Edited by ckrusor on 03/16/2011 12:16:45 MDT.

Henk Smees
(theflyingdutchman) - MLife

Locale: Spanish Mountains
This ain't fair on 03/15/2011 14:32:59 MDT Print View

Hi Colin,

This ain’t fair. It’s only a few weeks ago that I received (from Steve Evans) a few feet of his 0.003” ti sheet. I THOUGHT I had some good ideas about turning this into an UL multi-fuel stove and was only waiting for a few packages of JB-Weld (can’t buy this here in Spain and they’re in the mail) to start working on same and now you’re “throwing soot in the food” (the old Dutch saying “roet in het eten gooien” means you’re spoiling the fun) with this absolutely stunning design of a roll-up wood stove. Now I HAVE to go back to the design-table and start all over again. I HATE you – just kidding :).

I’m really impressed with your stove and can only say that I fully agree with what all the others have said before. I’d be one of your prospective buyers if it wouldn’t be for the fact that I already bought the ti-sheet, so now I have to turn this into SOMETHING (even tough it won’t -not even remotely- be as nice as yours). Whatever comes out, I’ll have to live with it.

Edited by theflyingdutchman on 03/15/2011 14:35:53 MDT.

John Nausieda
(Meander) - MLife

Locale: PNW
roll up stove on 03/15/2011 15:02:26 MDT Print View

Good move on the patent. I'm wondering one thing right off the top of my head: What is the largest pot relatively full of water that the stove can handle without tipping over? Width? Must that pot be without a handle unless it is a removable handle since the stove is more or less symmetric? Another issue. Many people at BPL us pop-can alcohol stoves. Is there anyway one would fit down in the stoves bottom for alternate use? And I notice all of those air-holes punched all the way through. I'm wondering if some could be left mostly punched though as on some Anti-gravity gear windscreens so you can close some up in the face of a strong wind. Many Asian stores sell stainless steel sink traps . Most are very cheap and could be recycled at the end of their service life.

Colin Krusor
(ckrusor) - M

Locale: Northwest US
Stove on 03/15/2011 16:16:12 MDT Print View

John,

I'm not familiar with the Anti-gravity gear windscreens. They have metal tabs that can be bent toward or away from a hole to allow more or less air to pass through? I think flex fatigue would eventually cause flexible tabs to break off with titanium.

One of the objectives I had in mind when I made this stove was improved reliability with damp fuel. I found that the air holes help it to burn hotter and more vigorously, which aids in keeping it going when the fuel you're adding is damp. This also requires more tending and feeding of the fire, and it makes the design somewhat sensitive to wind. This approach is the opposite of a Caldera Cone, which burns more slowly and has excellent performance in wind but can sputter out if the fuel is damp because air throughput is small.

I don't know how this stove would fare with heavy pots. The footprint is a 4.5" diameter circle, so it should be pretty stable, but I haven't tested it with anything more than a full Firelite 900.

I haven't tried an alcohol stove inside yet, but esbit tabs work well. In fact, the screen at the bottom already has a bump in the middle, and I was thinking about giving this bump a flat top to accommodate esbit tabs or alcohol stoves.

John Nausieda
(Meander) - MLife

Locale: PNW
Roll-up stove on 03/15/2011 16:35:49 MDT Print View

Absent bendable tabs for windscreen holes I would then just use aluminum foil over the holes in the case of severe winds or constant winds from one side etc. The pot size is something I consider to be very important . In my case I'm usually traveling with my wife and daughter so that pot size is about right for us. For larger groups some might want to see a scaled up stove but it's also possible that you would just bring two stoves. The Esbit option seems ideal to me for back up , but the alcohol option would really help in those situations where wood fires are technically prohibited.

Jim Pemrick
(Troy64) - F
Provisional Patent on 03/15/2011 17:38:29 MDT Print View

A US patent gives you the right to exclude others from making, using or selling your invention (in the US) for a period of 20 years from the date of filing. Of course, you can license your patent to others for a fee.

A provisional patent application only locks in your date of invention and gives you priority over later filed inventions that may be similar. In itself, it does not give you the right to stop others from making, using or selling your invention, only an issued US patent can do that.

You must file a regular utility (non-provisional) patent application within one year from the date of filing the provisional application. It typically takes the USPTO (US Patent & Trademark Office) about 2-3 years to send you out a first office action. So you are looking at 3-4 years until the application issues into a patent if it is found novel.

The wording of a patent application is critical and many pro se inventors (inventors that write and prosecute their own applications) end up with patents that have very limited if no commercial value.

If you are serious, I would recommend hiring a professional (e.g., a registered patent attorney or patent agent) at some point. If anyone offers to market your invention for a fee, run away as fast as you can. If you see ads on TV or in magazines, do not use them.

Please PM me if you have any additional questions regarding the patent application process.

Colin Krusor
(ckrusor) - M

Locale: Northwest US
Stove on 03/15/2011 19:00:18 MDT Print View

Thanks for the information and advice, Jim.

Ben Egan
(benjammin21) - M

Locale: The Grid, Brooklyn
cool stove on 03/16/2011 14:10:46 MDT Print View

That's a great stove. And a great idea.

I was wondering where you got the titanium? The titanium foil as well as the center pieces.

And how it was cut? The holes and the center pieces.

Thanks,

Ben

Derek Goffin
(Derekoak)

Locale: North of England
Roll-up stove on 03/16/2011 14:31:52 MDT Print View

Hi Colin,
If you change the top pot triangle so you can use straight pegs and drop it over the heads so they cannot move apart and it can only lift off not slide sideways, and put the pegs not inside but outside the foil body through the 6 main outer tabs it would trap the foil. Then the cinching tabs would not be needed or at least would not be so important. Your door would have to go over the pegs somehow.
A preheated secondary air supply with a second half height outer foil cylinder in lighter foil should be possible to add for some sectors of the market, also I suppose an insulated foil base to stop scorching for the ultimate LNT.

Steven Evans
(Steve_Evans) - MLife

Locale: Canada
Re: Roll-up stove on 03/16/2011 19:31:17 MDT Print View

That looks great! Very cool and good for you for thinking outside of the box. I really think there is some potential for something like that.

Laser cutting is the way to go for the thin titanium. I have cut my 0.003" ti foil with the waterjet but it doesn't leave a very nice finish. I wouldn't say it is "bad" but just not clean.

Here a picture of the squeezebox I cut for Kevin a while back. He may have some better pictures but you can see the rippling.

WJ Ti Foil

And just to get the mind churning, if you used the 0.003" stuff, you could weld it into a permanent cylinder and it would still roll up tight. Sort of like a version of the Titanium Flexible Windscreen available on my website. Just thinking out loud.

Colin Krusor
(ckrusor) - M

Locale: Northwest US
Stove on 03/16/2011 23:16:40 MDT Print View

Ben, the foil is from ebay (the same seller still advertises it, I think) and the Ti sheet is from TitaniumJoe. The foil was cut with scissors and a punch was used for the holes. The sheet was cut with a radial-arm circle cutter in a drill press and a dremel.

Derek, I have considered some of those ideas (upright rods on the outside, double wall). I think they definitely merit some exploration. At this point I feel like I'm afloat in a sea of ideas and I need to do some more tinkering to weed out the bad ones (whether any will remain after that remains to be seen).

Steve, thanks for the advice about cutting. I've been in contact with several laser cutting shops here in central CA, and a few have said that cutting Ti foil is a specialized operation and they aren't equipped for it. I'm still looking. I'm also going to order some of your 0.003" foil this evening. I played a bit with some 0.005" CP2 foil a while ago, and found that it was difficult to cleanly punch. It would tear or distort around the holes. Is your CP4 foil punchable?

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Stove on 03/17/2011 03:05:46 MDT Print View

> I sent in a provisional application for a utility patent this morning
Could be invalidated by the prior publication here, although there may be a small time window allowed - check.

> the 15-3-3-3 alloy foil becomes brittle after the beta transition, and can crack at the edges.
> I'm personally interested in trying 0.003" CP4 foil,
Indeed, the highly alloyed varieties are not so good for repeated thermal cycles plus mechanical cycles. Yes, I would try a CP foil.

> I'm afraid the thinner and softer foil might warp or bulge when red-hot.
Ah well, if it gets really bright red there could be a problem if the stuff is under load, but I doubt that a wood fire would get hot enough for it to be a problem. Only one reliable way to find out though ... :-)
I thought you were using 0.005" foil? You could always go up one thou'.

Cheers

Edited by rcaffin on 03/17/2011 03:06:49 MDT.

Jim Pemrick
(Troy64) - F
First to Invent in US on 03/17/2011 04:55:26 MDT Print View

The United States uses a first-to-invent system, unlike most other countries in the world. Invention in the U.S. is generally defined to comprise two steps: (1) conception of the invention and (2) reduction to practice of the invention. When an inventor conceives of an invention and diligently reduces the invention to practice (by filing a patent application, by practicing the invention, etc), the inventor's date of invention will be the date of conception. Thus, provided an inventor is diligent in actually reducing an application to practice, he or she will be the first inventor and the inventor entitled to a patent, even if another files a patent application, constructively reducing the invention to practice, before the inventor.

However, the current patent reform bill will change the US to a first-to-file system. This is a major change in the US patent system, but will make our patent system more similar to other foreign patent systems.

Bottom line - When the new patent reform bill passes, do not publish anything without filing a patent application first.

Jim Pemrick
(Troy64) - F
102 on 03/17/2011 05:02:00 MDT Print View

Under section (b) below, as long as the inventor files within one year of the date of public disclosure, then the disclosure (i.e., web post) cannot be used as prior art.

35 U.S.C. 102 Conditions for patentability; novelty and loss of right to patent.
A person shall be entitled to a patent unless -


(a) the invention was known or used by others in this country, or patented or described in a printed publication in this or a foreign country, before the invention thereof by the applicant for patent, or

(b) the invention was patented or described in a printed publication in this or a foreign country or in public use or on sale in this country, more than one year prior to the date of the application for patent in the United States, or

(c) he has abandoned the invention, or

(d) the invention was first patented or caused to be patented, or was the subject of an inventor's certificate, by the applicant or his legal representatives or assigns in a foreign country prior to the date of the application for patent in this country on an application for patent or inventor's certificate filed more than twelve months before the filing of the application in the United States, or

(e) the invention was described in - (1) an application for patent, published under section 122(b), by another filed in the United States before the invention by the applicant for patent or (2) a patent granted on an application for patent by another filed in the United States before the invention by the applicant for patent, except that an international application filed under the treaty defined in section 351(a) shall have the effects for the purposes of this subsection of an application filed in the United States only if the international application designated the United States and was published under Article 21(2) of such treaty in the English language; or

(f) he did not himself invent the subject matter sought to be patented, or ...

Colin Krusor
(ckrusor) - M

Locale: Northwest US
Patent on 03/17/2011 10:59:36 MDT Print View

Jim, thanks again very much for this information and for your expert advice.

Roger, I found in my cursory patent-law reading exactly what Jim described. In the US, publication of the details of a "novelty" does not interfere with obtaining a patent (at least not within the first year following publication).

To be honest, sharing ideas with the MYOG community is a big part of my interest in MYOG gear. If I had to choose between protecting an idea from people like the mKettle guy and sharing it with the MYOG community, I would share it and let the mKettle guy have it. I'm glad that US patent law allows me to share and protect.

Colin Krusor
(ckrusor) - M

Locale: Northwest US
Developments on 03/17/2011 19:53:57 MDT Print View

One of the shortcomings of the initial design, I think, is that it is sensitive to wind. I experimented this afternoon with a windscreen. It doubles as a pot stand, and replaces the tent pegs in the initial design. The windscreen increases the weight from 2.60 oz to 2.75 oz, although it could be argued that the weight increase is somewhat greater than this because the three tent stakes in the prior pot stand design were multi-use.

wind

wind1

wind4

wind5

I also modified the bottom screen a bit to create a platform for an esbit tab or an alcohol stove. I haven't tried an alcohol stove yet, but I found that one esbit tab was not quite enough to bring the water to a boil (another half-tab was required). I put the pot directly on top of the stove (without the windscreen or tent-stake pot stand), but I think it was still a little too far from the esbit tab. I don't know if the same would be true of an alcohol stove. The tent stake pot stand, though, could be used alone, as a tripod, over an alcohol stove or esbit.


esbit

esbit1

Edited by ckrusor on 03/17/2011 19:55:26 MDT.

Mike M
(mtwarden) - MLife

Locale: Montana
esbit on 03/17/2011 20:54:06 MDT Print View

that definitely appears further (pot <-> Esbit) than any of the Esbit stoves I've used

Colin Krusor
(ckrusor) - M

Locale: Northwest US
esbit/alcohol on 03/17/2011 22:24:20 MDT Print View

Yes. I think some modifications would be required to make this stove compatible with esbit or alcohol.

Kevin Beeden
(captain_paranoia) - F

Locale: UK
a thing of beauty on 03/23/2011 12:57:13 MDT Print View

Without a doubt; beautifully made.

I can offer some expereince with water-cutting of 0.003" Ti foil, as Steve Evans gave it a go with his setup for an attempt at my Squeezebox Stove. Neither of us was satisfied with the result, as the edges were rippled by the high pressure jet, and left fairly rough. We concluded that laser cutting was probably the way forward for thin Ti foils.

I'd thought of making a roll-up Ti woodstove body a while back; an obvious progression from jointing cylindrical windshields, Caldera Clones, etc. and a discussion of the optimal grate area relative to the number of sides for a sheet-walled burner (an infinite number of zero-width panels is best: i.e. a circular grate). But I never got around to doing anything... Congratulations on a superbly implemented design. I love the stove door...

Edited by captain_paranoia on 03/28/2011 05:49:29 MDT.

J Thomas Peterson
(tpeterson1959) - MLife

Locale: Southwest
Wow on 03/23/2011 15:46:53 MDT Print View

I can't add anything that hasn't already been said. Brilliant workmanship.

Kevin Beeden
(captain_paranoia) - F

Locale: UK
some thoughts on 03/24/2011 07:15:24 MDT Print View

I only managed a quick look last night, but thought about it a bit on the cycle home...

It looks from the pictures as if the door is made as a continuous piece of the foil. For a maufactured item, this may be rather inefficient in terms of use of expensive Ti foil, and a two-part solution may allow you to use the foil more efficiently.

The other question that popped into my head was: can you open the door whilst the stove is running? Your photos show the door open, but I'm not sure how you avoid burnt fingers (some handy tool or tent peg, no doubt...)

Apologies to Steve for missing his post re. the Squeezebox.

Apologies also if I seemed to be dismissive with my comment about a roll-up stove being 'an obvious progression'; the problem is that when you've had an idea, it always seems obvious afterwards...

Connie Dodson
(ConnieDodson) - F

Locale: Montana
I like it. on 03/24/2011 09:29:16 MDT Print View

I have two of the smaller backpacking wood stoves that work very well: the titanium and stainless steel MK1-UL by DarenN and the stainless steel folding Woodgaz wood stove by Zelph.

"I'm glad that US patent law allows me to share and protect".

This, itself, is a primary reason U.S. moved ahead so swiftly in invention. Some people contribute, and, others may have a different idea inspired by the discussion.

"I do plan to make a few modified versions over the summer, though".

"Does everyone who expressed an interest see nothing about the first version that could be improved"?

I would say, any burn tests?

Over at bplite forum, the characteristics of the fire itself are considered. The volume of the wood stove is an imperative to function, as well as size and placement of holes, height of the fire grate, height above the flame, and such.

Then, get the specification of the metal and thickness of foil worked out.

Does your college have students in metallurgy or materials science classes or instructors teaching those subjects? The people good at that get top pay and it all seems to go to either the military or to "proprietary information". That is why during your college years is the best, if not the only time, to find these things out.

If not, just try different foils available.

Discuss results in a forum specifically of stove builders, as well, like bplite forum.

My college had a sequence of required courses in drawing, making a prototype and writing a patent. Signed, dated, bound notebooks (no pull-out pages) are a start. It is for your protection: "sign and date" every page of sketches, scribbles, and, notes.

It is the roll-up design that will likely get your patent. For patent purposes, because it involves art, as well, I suggest the design patent specify small differences like a Victorian or Art Deco motif, for example, are included. It is the hole size and placement, volume and the height and distance between involved that make it function exceptionally well.

I had fun with Myst when it came out, but steam punk? ;-) There are people who just love everything Victorian. Art Deco would be my choice.

I want one.

Edited by ConnieDodson on 03/24/2011 09:46:39 MDT.

Connie Dodson
(ConnieDodson) - F

Locale: Montana
Hmm.. on 03/24/2011 10:34:11 MDT Print View

"One of the shortcomings of the initial design, I think, is that it is sensitive to wind".

Hmm.. roll-up stove and windscreen wrap.

If the windscreen is foil, only partially encircling the stove, it could be moved and placed into the wind, or, not put in place for calm weather.

Colin Krusor
(ckrusor) - M

Locale: Northwest US
Stove on 03/24/2011 10:55:52 MDT Print View

Kevin, thanks for the observations about the water jet cutting. I'm looking for a laser cutting shop that is equipped to cut thin Ti foil, and it turns out these are not easy to find. It seems that I may have to affix the foil to a rigid substrate (plywood or heavy cardboard) for cutting, so it doesn't curl up.

I had considered designing the door to be a separate piece of foil, but I think I prefer the one-piece design. It's simpler, lighter weight, and more durable, I think, than a two-piece design with some kind of hinge. The door can be opened and closed securely when the stove is hot. The door has a bit of ceramic-fiber twine at the "latch" and can be opened when the stove is hot by a gentle tug on this twine. I'll be replacing the twine with a wire for durability. The protruding tabs from the lower ring allow the stove to be grasped (with gloved fingers) while the door is pulled closed.

Connie, thanks for the input. I have considered a large number of foil options, and I made quite a few prototypes from stainless steel foil to arrive at the current arrangement of holes, the burn chamber volume, etc. I found CP2 foil (like that sold at Ti Goat) a bit too soft, and 15-3-3-3 foil a bit on the brittle side (although maybe serviceable). I am now experimenting with CP4 foil, which I hope will be a good compromise. The arrangement of holes and the shape of the screen allows a large air throughput, which helps to keep the fire hot but also goes through the fuel pretty fast. My intention was to design a light stove that performs best with suboptimal (damp) fuel, which is a typical situation in the NW where I do most of my hiking. This design is not as well suited to areas (like the SW) where fuel might be good quality (very dry) but scarce. I'm working on a way to adjust airflow, though, to make the burn rate controllable (without introducing too much complexity). I'll consider posting this to bplite or one of the other stove-focused forums, as you suggested.

Thanks again for the feedback.

Kevin Beeden
(captain_paranoia) - F

Locale: UK
re: US patents on 03/24/2011 12:24:28 MDT Print View

It's interesting to see comments re. US patent law, and how it differs from the rest of the world. In the rest of the world, we usually refer to the US patent process as being 'first to file', in that the protection is applied at the point of application. So, if someone publishes an idea, and someone else then applies for a patent on that idea, it seems that the person who applies (files) the patent acquires the patent rights. This can lead to a situation where the actual inventor doesn't get the rights to their idea.

My understanding of this may be wrong...

In the UK (and thus rest of the world bar US, which uses the same model for patent law), a prior art search is performed. Thus, if 'prior art' is found during the patent search, the patent application (e.g. by a third party) is likely to be rejected. It does require the 'prior art' to be found; a limitation of the system. However, appeals on the basis of previously published prior art may well be used to contest a patent grant. One cheap way of preventing anyone else from patenting the idea is to apply for a patent, but allow the application to lapse; since patent searches are performed on previous patent applications and grants, it ought to be found.

The fact that publication of prior art may make a patent grant impossible is what encourages potential patentees to remain silent until an application is made (notwithstanding non-disclosure agreements). The patent application is the vital part of the process, and the drafting of this application is critical; no further 'claims' may be added to the application beyond this initial submission (revisions are often made in the light of the patent review process and prior art searches).

The original purpose of UK patents was to spread knowledge of technologies by publication of patents; the exclusive rights that accompany this publication is the 'reward' for sharing technology.

As for Connie's comments about including 'art' (e.g. Victorian, Deco etc) in the patent, this may be a misunderstanding of the use of the term 'prior art'. In the UK, certainly, stylistic art plays no part in a patent application; a patent is concerned purely with the functional aspects of technology. Stylistic art features use a different form of protection; either a Registered Design, or a Copyright. In the UK, a Registered Design would be a pretty good way of protecting this stove design.

Of course, as with all Intellectual Property, actually contesting violations of your rights (be they patent, Design, or Copyright) is an expensive business. And, as such, it may not be worth taking out any form of protection.

Kevin Beeden
(captain_paranoia) - F

Locale: UK
re: door hinge on 03/24/2011 12:31:44 MDT Print View

> It's simpler, lighter weight, and more durable, I think, than a two-piece design with some kind of hinge.

All certainly true. But likely to be more expensive in material cost, which was my thinking (being an engineer, my brain can't help considering all the various efficiencies and manufacturing costs...)

As for a hinge; well, with such thin foil, I don't think you'd need a hinge (just as you don't at the moment). You'd just fasten one end to the body, rather than cutting the entire thing in one piece. It was merely a cycle-home thought, and not a major criticism.

Colin Krusor
(ckrusor) - M

Locale: Northwest US
Door on 03/24/2011 17:03:18 MDT Print View

Kevin, I think you're right about keeping materials cost in mind in finalizing the design. It's a good idea. I think in this case, since this stove won't require any welding, and a little bending (rod and sheet) for the pot stand is really the only fabrication operation beyond cutting out the pieces, I'll accept the extra materials cost that the one-piece design entails.

Your idea is a good one, though. I don't mean to seem dismissive of it. I'll keep it in mind in case materials costs seem to be getting out of hand.

Eric Blumensaadt
(Danepacker) - MLife

Locale: Mojave Desert
Elegant! on 03/24/2011 22:37:16 MDT Print View

A very elegant and simple design.

I feel your improved windscreen is important. If it were ADJUSTABLE for pot size (within limits)and let the pot sit down in bit you'd greatly improve the stove's efficiency. This would put it above the less efficient Bushbuddy and Bushcooker "sit-on-top" pot holder design.

I just bought a Caldera Cone Sidewinder with the Inferno woodburning kit. It too rolls up and stows inside the pot I got with it. The nice thing about the Sidewinder is that Trail Designs has figured out how to make it work well with alky and ESBIT. That's your challenge.

Plus, of course, all Caldera Cones fit their pots closely and gain great efficiency. Their "custom fit" design requires you to use pots of only one diameter and height per CC stove. A close-fitting Adjustable windscreen is the advantage you'd have.

Several slots to recieve the windscreen's horizontal tabs would likely give you that diameter adjustability. Your overlapping design is EXACTLY what's needed to make the adjustability work. To support the pot just use two Ti tent stakes through holes.

Good luck!

Edited by Danepacker on 03/25/2011 00:36:51 MDT.

Kevin Beeden
(captain_paranoia) - F

Locale: UK
re: manufacturing on 03/25/2011 08:24:22 MDT Print View

Colin, no worries about your comments; as someone mentioned earlier, it's nice that we can discuss design issues like this. And you're certainly right that you'd need to calculate both material and machining costs for any production solution.

JD McGyver
(jdmcgyver) - F

Locale: Texas
Re: Roll-up stove on 03/26/2011 08:46:40 MDT Print View

I work with AutoCAD for a living. Many of my clients do plasma, abrasive waterjet and laser cutting. I know exactly what is necessary. I'd be happy to program the part for cutting and adjust the part as it evolves. My only fee would be your sending me a free stove with each new revision that is made.
All I need is a tracing on paper mailed to me.
FYI I have a large format scanner that handles 40" wide x any length if any of the other folks need CAD files for projects. I'd probably be willing to work the same type deal.
Let me know if you are interested.

Colin Krusor
(ckrusor) - M

Locale: Northwest US
AutoCAD on 03/26/2011 12:32:37 MDT Print View

Hi JD,

I actually found a plugin that allows me to export the design from Sketchup as a .dxf file for laser cutting. The major obstacle at this point is locating a laser cutting shop that will cut thin Ti foil under argon for a reasonable rate. If I run into any difficulties with rendering the design into the .dxf format, though, I'll let you know. Thanks for the offer.

John Nausieda
(Meander) - MLife

Locale: PNW
Roll up stove on 03/26/2011 13:00:36 MDT Print View

Here are some folks using scroll saw blades, and bandsaws to cut titanium.
http://bbs.homeshopmachinist.net/archive/index.php/t-23474.html

Colin Krusor
(ckrusor) - M

Locale: Northwest US
Tools on 03/26/2011 14:43:58 MDT Print View

The foil, the sheet, and the rods can all be pretty easily cut with hand tools. The prototypes pictured in this thread were made with stout scissors, a sheet metal punch, a drill press with a radial arm circle cutter, and a dremel tool (and a propane torch for bending the rod). For me the stove is about an eight hour project using these tools. Shaping the rings from the 0.016" Ti sheet with the dremel tool is the most time consuming part of the process.

This fabrication process is fine for making one at home for myself, but it is much too time consuming for producing 20-50 units. Producing this stove in quantity and making it available to interested people on this forum will require a laser cutter.

leon lynes
(mrgadget921) - F

Locale: south west
Re: Door on 12/27/2012 19:09:40 MST Print View

kevin was spot on... material investments...
but I want to add my 2 cents also for LONGEVITY...
I think I saw 2-3 cracks/tears in your photos...

I WANT ONE! heavier is better / UL I am not... yet... IT IS MY LONG TERM GOAL...
but the gadgets keep coming!

Edited by mrgadget921 on 12/27/2012 19:10:59 MST.

Colin Krusor
(ckrusor) - M

Locale: Northwest US
Stove on 12/27/2012 23:17:34 MST Print View

Hi Leon,

I do plan to revisit this project sometime soon, but I'm still in grad school and it isn't easy to find time for it.

There is only one crack/tear that I have noticed, but I agree that this problem would need to be resolved before I considered making any stoves for anyone else. A softer alloy, like CP4, might warrant consideration.

I'll post updates as soon as there is anything new to report, but I can't promise to get to it right away.

leon lynes
(mrgadget921) - F

Locale: south west
don`t let the embers die! you have a smoking hot product! and timing.... on 03/27/2013 19:03:13 MDT Print View

true I can just flatter you by imitation, but it is your novel idea.... that makes me envious.... gotta have one! could very easily pay for tuition!!!