Mar 25, 2013 at 5:08 pm #1300883
I like the Esbit Titanium Folding Stove as it is clever design and pretty easy to use. As I have designed Esbit stoves before and thought that I would see if I could tweak the design and come up with a more efficient design. Well, I think that I have done this and I also think that this is a great DIY project. The idea is to add a ring to focus the airflow into and out of the Esbit cube (see the picture below):
By doing so, I believe that this has increased the efficiency of the stove. Compared to a control test, I was able to heat up 4 cups of water 15 F hotter when using the ring (n=1). As I said earlier, I think that this is a great DIY project and who share this initial discovery with you. This design is far from optimized and there may be a lot more gains to be made by further tweaking of the concept. Best regards – Jon
If you wish, I made a video of the idea and test:
Mar 26, 2013 at 2:07 am #1969641
@stingray4540Locale: South Bay
Hmmm. Nice idea.
What about making the ring taller to act as your windscreen as well? You could also cut notches in the bottom so it slips over the arms and sits lower to the ground, then you could play with how much air to give it to get the best efficiency.
It also might be worth playing with a larger diameter, or even an inverted cone…Mar 26, 2013 at 7:44 am #1969685
Looks like taking the bottom off of a cat food can will get the job done? I'm going to try this when I get home to see what this does for my kit.
Thanks for sharing Jon!Mar 26, 2013 at 9:56 am #1969714
Dan YeruskiBPL Member
Great idea, thanks for sharing.Mar 26, 2013 at 3:26 pm #1969841
What was the difference in the residue deposited on the posts after each burn? That would tell you something about efficiency as well.
Plus, did I understand the video correctly. Was the tab you used with the focusing ring broken? If so, then the added surface area for combustion could potentially explain the higher temperature you got with the experimental case versus the control.Mar 27, 2013 at 3:38 pm #1970254
Michael, I don't think that the cracked Esbit would make a difference. If I broke up the Esbit into four pieces to increase the area I would increase the burn rate but have little effect on efficiency. Besides the overall time to flame out was close betwen the to test. JonMar 27, 2013 at 3:43 pm #1970256
Excellent stuff and Thanks! I will play with your great thoughts soon.Mar 27, 2013 at 3:45 pm #1970257
I am just guessing here, but I would not be surprised if the flame out time is not the best measure here, as it assume the same energy output pathway over time. But regardless, the easy way to answer this is just do some more trials to see if the results are repeatable. Preferably with a more identical experimental set up (i.e., unbroken tab)Mar 27, 2013 at 3:55 pm #1970260
Michael, I agree more testing should be done. Here is the way that I looked it: if the focussing ring increased the final water temperature by 15 F for 4 cups, then when boiling 2 cups, it should be ~30F. Even with some experimental error, getting Esbit to output a 30 F change is in the direction of goodness. Since I am not a die hard Esbit user AND there a lot of them on this forum, I thought it would be a good DIY project. The Esbit Ti folding stove has some physical limitations that might limit optimization (particularly the overall height). So, I posted this finding as a starting point for others to tweak and optimize. At the end of the day, this group might come up with a pretty slick and efficient system. JonMar 27, 2013 at 4:33 pm #1970271
exactly. I am a user of the esbit wing stove (not surprisingly given my interest). and in theory i should shut up and do the testing myself. right after I figure out how to get away from this computer and do some real hikes. if someone else beats me to it, though, I won't complain.Mar 28, 2013 at 12:36 pm #1970523
Here is a simple idea at 0.1 Gram a Starbucks Double Shot can cut to fit. It is like the Gram Cracker. I might punch some holes in the top of Starbucks can top to see if the flames spread better.
Mar 28, 2013 at 12:49 pm #1970527
my thinking exactly, in terms of materials (cheap Al can). eager to see your results.Mar 28, 2013 at 1:13 pm #1970538
I think that you will find that the aluminum will get too hot and anneal to a very soft state. It would probably be better to get some titanium foil and make the shape. Send me a PM and I can probably send you a scrap piece or two that would be the right size. JonMar 28, 2013 at 1:36 pm #1970545
Jon, I have a hole punch and was thinking of putting maybe 4-5 holes around the top to see if this spreads the flames a little better underneath the pot. The aluminum can is recyclable and I a can use a different Double-Shot can on every trip. But Ti does last longer and I would like to try it out if you have some to spare. I will PM you.
Jay WilkersonMar 28, 2013 at 4:21 pm #1970602
I will test the theory this weekend. Ti Wing/Kinda Gram CrackerMar 28, 2013 at 8:13 pm #1970661
Starbucks Double Shot can at 0.1 gram- Almost a Gram CrackerMar 28, 2013 at 11:22 pm #1970698
I started this thread a week or so ago.
The cat can idea I had at that time didn't work out at all. I read this thread and figured that I'd give it one more try. I cut a 1/4" off the bottom and it fit perfectly on the stove. If you follow the link, you'll see that the can is well ventilated.
I first tried it with a .25oz Coghlan tablet. There was no difference in burn times or the temperature obtained. I then tried it with the .5oz Esbit tablet. Once again, no notable performance difference.
I have some aluminum from a craft store that I use for my windscreens. I'm going to play around with it and try to figure this one out. I'm sure using reflective material will probably help but I suspect that ventilation plays a key role in this project as well.
The cat food can will be officially retired to the garbage can.Mar 31, 2013 at 4:16 pm #1971473
Hey Jon, You were correct about the aluminum. It started to catch fire then it got bent out of shape and wrinkled up quickly! It seems like Titanium is the only answer. I will try that next. ThanksMar 31, 2013 at 5:41 pm #1971496
Start with the 6 ounce steel can and dial in the design. Then switch over to titanium or stainless steel. The titanium foil that I sent you should arrive early in the week. JonMar 31, 2013 at 5:48 pm #1971501
Thanks Jon, I will look for a steel can to cut to shape.
JayMar 31, 2013 at 7:47 pm #1971541
John DonewarBPL Member
@newtonLocale: Southeastern Louisiana
I'm not so sure that aluminum is a complete no go for this idea. I used Home Depot aluminum flashing on a somewhat similar project and saw these results.
I was using a tray stove like the one pictured below.
It was set up under my 1 cup cook pot as seen in the next picture.
After a test burn and boil my combo windscreen and pot support looked like this…
…it developed a copper toned patina due to the discoloration of the coating on the aluminum flashing material. The good news was that it maintained its shape and mechanical strength.
The ends were joined with eyelets and the holes were punched with a standard paper hole punch.
Based on my results I'm pretty sure that a serviceable focusing ring for the tri-wing Esbit stove can be made from aluminum flashing.
My combo windscreen weighed in at 7 grams. I am interested in seeing what a focusing ring made of Ti weighs for the tri-wing Esbit stove
NewtonMar 31, 2013 at 8:15 pm #1971551
@b-g-2-2Locale: Silicon Valley
Newton, the advantage of the Trail Designs Gram Cracker is that it folds down to almost nothing. Yours looks like it might be durable enough, but bulkier.
Yup, you can do a lot with aluminum roof flashing. I wonder why they don't sell titanium roof flashing!
I used to call it a flame concentrator. You call it a focusing ring.
–B.G.–Mar 31, 2013 at 9:26 pm #1971566
John DonewarBPL Member
@newtonLocale: Southeastern Louisiana
I was only showing the components of what I used in my tests. I believe the tray stove puts the fuel tablet in roughly the same height from the "ground" as the tri-wing stove.
The picture of the stove was only there to show what was used and not in comparison to the Gram cracker or a Tri Wing Esbit stove.
If you view the video at…
…you'll see it was Jon who dubbed it a focusing ring. I actually call mine a combo windscreen and pot stand. Look closely in the second picture of my post, the "combo" is supporting my cook pot, resting on the reflective surface and encompassing my tray stove.
My post was meant to show that I think the aluminum can version failed only because it was too thin and not because it was aluminum. The first line of my earlier post should have made that clear.
Happy Easter Bob. ;-)
NewtonApr 1, 2013 at 9:02 am #1971654
@kaydubLocale: N. Idaho
It seems like if I could mount 2 wings on the long sides of the platform, I would have a gram cracker with a potstand, & I would just use the windscreen I use with my cat can stove.
So what is the height of the pot over the Esbit when suspended in the Caldera Cone?Apr 2, 2013 at 4:18 pm #1972123
Thayne NBPL Member
but nice minor threat sticker ya got there Jay!
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