"Conversely, when the weight is resting on the stove, the cone doesn't add much stability because if the pot starts tipping, the cone can just slide with it and the pot can tip inside the cone or slide off the stove. Having the cone trying to keep the pot on the stove is better than a traditional windscreen, but still not nearly as stable as having the pot resting on the cone".

Dan, I think you gave up too soon. You should have tested the stability of the pot on the StarLyte while inside the cone. Having the cone right next to the pot will give it plenty of stability. I seriously doubt if you could tip it over any easier than having the pot rest on the cone. Rand talked you out of it. Now you have extra parts and that includes the lid. Once you’ve determined how much fuel to use, that amount will be consistant from one boil to the next. inside the cone. Measure your fuel (1/2oz) and there is no need to put a cover on the Stove, just let it burn out.

I’ve had a few ask where to get the lid. It comes with a can de-solder wick. 10 rolls of de-solder wick per can. Use one roll at a time and cover the remainder to prevent drying out of resin. I have not tried to source them out as of today. I'm playing with stove/pot assembly :-)

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Edited by zelph on 02/14/2012 18:17:40 MST.

I do still have the Starlyte pot support. I just slipped it back in to play with.

I can see a pretty good argument being made for using the Starlyte pot stand instead of the original Trail Designs stakes. It's a whole lot lighter (2g vs. 16g) and one could argue that it's sufficiently stable and quite a bit simpler. My MYOG 2g Ti stakes erase most of the weight difference, but the pot stand is still much simpler.

Compared to the silicone band though, I don't see an advantage gained by using the integrated pot support. The simplicity is the same since the band always stays on the pot, the weight is within a few grams (2g vs. 5g, maybe less) and without the pot support, the stove leaves more space inside my pot for other stuff.

Regarding the lid, using the silicone band (or stakes) gives me the option to use the lid or measure my fuel. So I'm not necessarily needing the lid. I could leave the lid at home and measure, but then I would need something to measure my fuel with, so I'd still have the same number of pieces. I could leave the measuring piece at home and use a fuel bottle with markings, but that's less accurate and I'd likely burn off more fuel than the lid weighs. So this decision comes down to simplicity (measurement marks) vs. lighter weight (lid). Using the silicone band lets me go either route.

Edited by dandydan on 02/15/2012 17:53:22 MST.

If your cone is not completely round at the top your silicone band is going to melt and stink. My cone is not round and will allow a lot of heat to attack the silicone band. I have pliable measuring cups that I include with all stoves. I can send you a life supply at no charge. They are 1oz capacity graduated in oz and ml.

The cone right up against the pot while sitting on the StarLyte pot support will prevent the pot from spilling your precious water/dinner. The set-up I made with the Kmart grease pot and StarLyte stove could not be tipped over or spill the contents. The pot sides was 1/8 inch from the top of the cone teepee angular windscreen.

I'm the kinda guy who likes life to be as simple as can be. I like as few pieces as possible. No one really likes stoves that have to be primed in one way or another. The StarLyte is a champion when it comes to "user friendly" absolutely no priming necessary in cold weather. The burner that comes with the Caldera requires priming. I just recently tested mine, I know for a surety. Requires matches, not a bic type lighter to ignite it.

Thanks for the offer Dan. I actually have a few of those 1oz measuring cups around (they come with the TD cones), although I've never tried them. I should give them a chance. I've always assumed that fuel usage would vary quite a bit depending on water temperature and wind, so I've preferred to over fill, snuff and recover using the vacuum nozzle from Packafeather.

Once I get this cone dialed in, and I'm confident of how much fuel a pint will take then I'll try using the measuring cup. I'm having some awesome results right now.

Packafeather fuel sucker cap: http://packafeather.com/fuelbottle.html

Last night I spent way too much time playing with the variable of 'pot height'. The results are really interesting. I did multiple (2) tests at each height and averaged the results (although both tests were always very close because I've been diligent with controlling the conditions).

The stove is 0.8" tall, so the gap between the stove and pot (which is what I'm really playing with here) is 0.8" less than these absolute pot height figures.



Important: These tests were done with very cold water (40F), 500ml of water (6% more than a pint) and methanol fuel (less hot and energy dense than ethanol), so much better results would be achieved using ethanol and a pint of 60-70F water, which seems to be more of the norm.

We can see that fuel economy improves the lower the pot is inside the cone. Pretty straight forward, but good to confirm with actual tests. This makes sense because more of the pot in inside the warm cone, plus the stove is burning slower (due to having the pot really close) which improves fuel economy. Ultimately you could probably get the pot too close and mess up the combustion so much that it burns poorly and thus fuel use increases.

The boil time results are more interesting. We can see that if the pot is too low (ie. 1.4", or a 0.6" gap) then the stove is really getting stifled and a boil takes forever (~13 min) even if we do get great fuel economy. As you raise the pot up, the boil times get faster since the stove has more room to burn. This is true until you reach the point where performance diminishes because the stove is already burning as hot as it can, and the pot is just getting further away. The fastest boil times occur in the 2.0 - 2.3" pot height range (1.2 - 1.5" gap).

With those results, we can choose a pot height that strikes the right balance between speed and fuel efficiency. There's not much point in going lower than 1.8" (1" gap), because the fuel savings are tiny and the boils get a lot slower. In the context of my cone setup, 1.8" is a good height that's biased a bit more towards fuel economy. Going up to 2.0" shaves a full minute while increasing fuel use by 9%. This is a good option for people who don't mind burning an extra 1.5 grams in exchange for a minute saved. Any pot height that's higher than 2.0 isn't going to be much faster (eventually it gets slower) and it's going to burn a lot more fuel.

So the conclusion is that the reasonable range of pot heights is 1.8 - 2.0", with 1.8" being fuel economy oriented, 2.0" being speed oriented and 1.9" likely being a nice all around compromise with boil times in the 9 min range for this ice cold water.

For comparison, my original ULC cone with the wider 0.9L pot and the Trail Designs 12-10 stove averaged 16.5g of fuel with a 8.25 minute boil time in the same conditions. This is very close to the performance I'd get with a 1.9" pot height. At that height, my setup would probably do 16.4g with a 9 minute boil, which is a wee bit worse overall, but I think most of that is attributable to the narrower pot, which is fundamentally less efficient.

------------------------------------

Prior to all the testing last night, I did add 8 holes to the bottom of my cone with a hole punch, as I felt it needed a bit more flow. That had a big positive effect (30 second faster boils using nearly 2g less fuel) and I believe I've pretty much nailed the cone design now, so I doubt I'll make further modifications.

I also trimmed the silicone band is half (again) last night. It's still working great and now weighs just 2.5g. Awesome.

Going forward, I've got the cone design and pot height figured out, so most of the work is done. I'm going to play around with different amounts of water and different water temps to get a better understanding of how the performance will vary. As well, I'm going to get out in the field and do some tests in windier conditions and with cooler ambient air.

Edited by dandydan on 02/15/2012 23:15:37 MST.

Hi Dan, pretty interesting.

I'm not too familiar with the stove you are using. Does it have a large single open chimney flame similar to the 12-10 stove?

Your results are interesting. Efficiency and time aside, for me the real interesting result is that the lower distance between the stove and pot bottom will allow for an overall smaller cone, which means that it will be easier to have a cone that fits inside your pot and possibly an overall lighter weight.

In my non-rigorous testing, initial water temperature is the parameter that seems to overall have the largest affect on time/efficiency for me. When I am out and about I will often try to pre-heat my meal water in my pack next to my back, or if I am camping next to a cold lake or stream, I will leave a pot full of water to "warm up" by itself on the bank.

Edited by eatSleepFish on 02/15/2012 10:33:01 MST.

> The cone right up against the pot while sitting on the StarLyte pot support will prevent the pot from spilling your precious water/dinner.

Not really.....the pot sitting on the pot stand is not connected to the cone. It can slide off the stand pushing the cone sideways. The most stable scenario is to have the pot sitting on the wide base of the cone....not some disconnected tiny base.

> Ultimately you could get the pot too close and fuel use would increase, because a boil would simply be taking so long that you're losing heat to the ambient air and past the peak of efficiency.

Actually....the issue of getting too close to the stove is that you can choke off the ability for the alcohol coming off the stove to fully burn....and that will be the source of the inefficiency.....alcohol goes away but doesn't provide heat. In fact, the slower you burn, the more efficient you make it. The most efficient stove we ever made didn't achieve boil until 37 minutes.....and used almost no alcohol to get there. Slow = efficient....almost always....unless you're in a blizzard.

Rand :-)

Dan, I'm interested in your improved draught through the cone. What is the total area of air holes you have now ?

Thanks for posting the component weights Dan. With your new half band the total drops to 125.3g (a 61g savings over your previous system). Pretty sweet!

"...for me the real interesting result is that the lower distance between the stove and pot bottom will allow for an overall smaller cone, which means that it will be easier to have a cone that fits inside your pot and possibly an overall lighter weight."

Yeah the possibilities this opens up was the main draw for me too. With this stove and the pot positioned 1.8 - 2.0" off the ground, you free up 1.0 to 1.2" of height (3.0" is standard height) which enables either more efficiency (cone comes up higher on the pot) or you can chop 1.2" off the cone and save weight plus be able to use ULC style cones in pots that were previously a bit short, or needed to use a fry pan lid to get the cone in there. With my first 0.9L pot, the cone went from about 30g to 20g when I chopped off 1.2 from the bottom.

"initial water temperature is the parameter that seems to overall have the largest affect on time/efficiency for me."
I'm not sure if it's quite this simple, but in my tests I've been going from 40F to 210F (boiling temp at 2000') which is a 170F degree rise. Starting with 70F water would drop that rise to 140F, which is only about 80% as much of a temp rise.

"...the issue of getting too close to the stove is that you can choke off the ability for the alcohol coming off the stove to fully burn"
Thanks Rand. It makes sense that it's more about ineffective combustion that losing heat to the ambient air. I wonder if you'd get higher carbon monoxide with the pot too low as well.

Hehehehe

Dandydan and I submitted comments at the same time and my comment came up short end of the stick.........oh well

Edited by zelph on 02/15/2012 16:02:35 MST.

"I'm interested in your improved draught through the cone. What is the total area of air holes you have now ?"

The picture below shows the 8 standard sized hole punch holes that I added in addition to the 5 larger ones that were original.

Adding these holes definitely increased air flow and improved the combustion efficiency, since before the boils were both slower (10:07 average) and fuel hungry (17.25g average). With the 8 added holes, boil time average went to 9:45 and fuel economy improved a lot to 15.65g. It's clear that combustion wasn't very efficient in the original setup.

However, it's possible that simply lifting up the pot a bit would have had the same air flow increasing effect as adding the holes. I did some quick pot height tests prior to modifying the cone, and raising the pot up 0.2" gave nearly the same results as adding the extra holes. So you've got two factors to play with here to get the combustion dialed in. The nice thing with not adding extra holes is that it might perform better in windier conditions. I didn't add too many holes though, so I don't think windy day performance will be too bad. I could easily set a rock or two in front of a couple holes on the wind ward side if it was really gusting.



BTW, this silicone band is now down to 2.5g and 1/4 of its original width, but it was a 'thick' wrist band that was about twice as wide as a normal wrist band. Even cut down this skinny, it seems to hold very well. I can pile at least 5 lbs on my pot without the band slipping, and a full 750ml pot would only weigh about 1.5 lbs so there seems to be no danger of that. I'm really happy with it.

I've ordered two normal wrist bands off of eBay ($0.99 shipped each) to experiment more with.

One thing to mention is that if you have a pot with lower handles, that could cause interference with the silicone band. The Evernew ECA278 750ml pot is the ultimate because it's high handles allow you to both use a silicone band and eliminate the handle cut out. Other pots could work with the band too, but you need a pot with removable handles so you can remove them to get the band on.

Edited by dandydan on 02/15/2012 16:15:23 MST.

Hey Dan, I love that you dive head first into modifying every piece of gear you get. A thought about the air holes: I think fewer holes might be beneficial in the sense that you can achieve higher air velocities and can get a chimney effect. Of course, too few might suffocate it, but "less is more" might be the case here. Of course, I think at a certain point it is splitting hairs.

Forgive me if I am being obtuse. I just received my StarLyte (awesome by the way Dan/Zelph) and I am debating whether or not to mod the stainless stand.

DandyDan's StarLyte data shows bringing 500ml (2.1 cups) of 60-70degree water to boil in 13 minutes with a 1.4" gap (minus stove height = about a 1" gap) between stove top and pot bottom ... target range would be 2" (1.5" not including stove height) for best all around by DandyDan's account.

Dan/Zelph's StarLyte data states bringing 2 cups of 69 degree water to boil in 6.5 minutes with a built-in pot stand that provides 1" gap between stove and pot bottom height.

Why are these data sets so different? Is the variable air? Fuel?

Dan/Zelph, I have read through most of your original posts as to how you developed the StarLyte, but I never really saw how you determined a 1" pot stand to be the right height.

Chris, I made a mistake in my previous posts when I was talking about the gap. I was mistakenly thinking the Starlyte was 0.5" tall, so when I had the pot at 1.8" I was saying my gap was 1.3". In reality, the stove is 0.8" tall so my stated gaps were off. My conclusion still stands that 1.8 to 2.0" pot height is ideal for my cone, but this corresponds to a 1 to 1.2" gap, not a 1.3 to 1.5" gap. So this is consistent with Dan/Zelph's findings that a 1" gap is ideal, and the slight difference is likely because of my cone environment needing a little more space to mix in the air. 1.0" is probably ideal with a windscreen, and 1.1" may be ideal in a cone, but it depends on the specifics of your cone. I'll correct my earlier posts.

The reason my testing results at 1" gap are worse than Dan/Zelph's with a 1" gap are:
1) I'm using 40F water, not 60-70 as you mention, so much colder than Dan's/Zelphs 69F water.
2) I'm using methanol, which is about 25% less energy dense and hot than denatured alcohol.
3) I'm boiling 6% more water (500ml vs. 473ml) as you mention.

For a better apples to apples comparison, I just boiled 2 cups (473ml) of 69F water with a 1.8" pot height (1" gap), so the only difference in the fuel being used (methanol vs. ethanol) and that I'm using a cone.

It took 8:10 and burned just 11.4g (0.53 fluid oz) of methanol, which frankly is unbelievable. If I was using ethanol/denatured alcohol, it would be have around 9g or ~0.4 fl oz of fuel (25% better). That's just one test though. Small sample size.

Edited by dandydan on 02/15/2012 23:25:45 MST.

I misread your water temperature, where you were talking about how it would be even better if the water was 60-70 degrees.

Thanks for clarifying.

I think this also intuitively answers my other question as well ... Dan/Zelph must have tested his way methodically to get to the 1 inch stand height ... which I probably never should have questioned considering his well honed reputation as a stove-wizard.

Hmmmm .... to cut or not to cut.

With a cone, height beyond a standard between stove and pot doesn't hurt that much. Many years ago when I first tested the cone, I did some tests with the 12/10 stove and found that the cones were generally spaced a bit close to the pot bottom.
Betwen 1-1.5" there was little change. From 1.5 - 2" there was a sligt change, about 5-10%. Between 2" and 3" there was only a 25% change in boil times (2cups of 40F water heated to 200F.) This is likely due to the cone trapping so much heat to begin with. However, dropping it from standard to 3/4" dropped output 25%.

Just some aditional data to work on. I had a chart of about 80 runs but it was lost when the old computer died. I have some old backup tapes...no interface to the tape drive (older SCSI) on modern machines.

n/m - double post

Edited by dandydan on 02/16/2012 16:51:15 MST.

"With your new half band the total drops to 125.3g (a 61g savings over your previous system). Pretty sweet!""

The main way to save weight at this point would be to ditch the pot handles, which weigh a combined 17.9g. Due to the low thermal conductivity of Ti, I could easily ditch the handles and just lift the pot up by the rim as I do with my 1.3L Evernew pot. However, I'm going to be eating/drinking out of this pot a lot when it's filled with really hot food/drinks (ie. mashed potatoes) so the handles are worth the 17.9g to me.

One possible avenue to explore would be the use of a neoprene cozy that would both protect me from the hot pot, and act as a cozy to keep the food/drink warm. If this could be the same or less weight, it would be an improvement.

Besides the handles, there's virtually no weight left to be saved. A 2.5g silicone band doesn't leave much room to shave weight, the 25g cone can't be made lighter, the only lighter pots are either smaller or fragile (beer cans) and the 7g carbon fiber lid is as light as it gets. I could save a few grams switching to a micro-Starlyte stove (http://www.youtube.com/watch?v=VT1gU7BUcF8)

I've basically accomplished all of my original goals as I laid out in my first post:
1) Simpler than 4 pieces (cone, 2 stakes, stove)
Now down to two functional pieces (cone, stove) and one static piece (silicone band)
2) Lights better in winter than 12-10 stove
Accomplished by Starlyte
3) Lighter
Now 125.3g instead of 186.4, a one third reduction.
4) Packs better
Everything (cone, stove, my spoon) now stores in a 750ml pot with no fry pan lid needed and lots of volume left over.

Edited by dandydan on 02/16/2012 17:09:14 MST.

"The main way to save weight at this point would be to ditch the pot holes, which weigh a combined 17.9g. "

Please clarify. Holes don't have weight.

--B.G.--