Chris, any interest in building a rocket stove(s)?

[rightisright]

Something along the line of this: http://www.amazon.com/Stock-Storage-GRS ... 331&sr=8-2

I'd love one to take camping and even use in my back yard. I know you wouldn't be able to make any $$ on a one-off. But there may be other members interested.

In case there is anyone here who doesn't know what a rocket stove is, here's a vid: http://www.youtube.com/watch?v=eSwZm1K1 ... re=related

[Greg]

Neat. Looks to work the same way as a Kelly Kettle, which is on my wish list.

[Netpackrat]

What Chris said. There's a lot of welding in that stove, and welding is one of the things that you can't readily speed up at our level of fabrication, no matter how many of an item you are making. About the most you can do is minimize the time spent changing your setups between welds through fixture design. If it could be made out of thinner sheet, and didn't absolutely have to be round or perfectly airtight, you might be able to bend it up from sheet and assemble using a resistance spot welder. But, you'd be trading welding time for cutting and forming time, which is time consuming at our level, so there might not be a lot of gain in the end.

[Darrell]

That top piece with the three raised cleats looks vaguely familiar... can't put my finger on it. It would help to be able to use "found" parts to speed construction, if possible.

[blackeagle603]

That guy needs some basic tortilla forming lessons...

A roller?

Seriously?

[Netpackrat]

Ah, I hadn't realized there was an inner liner. Definitely make the outer case square. Since the refractory material will protect it to some extent, no need to get carried away with the thickness. If a guy had a squaring shear and a pan brake along with the spot welder, that part would be relatively quick. Not really any way of getting around having a major welding operation on the inner piece.

Since you'll probably never beat the linked unit on price, make it out of stainless, and charge a premium. Make it as light as possible and target it at the REI type crowd. Stainless should be able to tolerate the heat in thinner sections better anyway.

[Netpackrat]

They don't need to be round, and the outer shell can be pretty thin sheetmetal, since the space between the shell and the combustion chamber is filled with cast refractory material.

Yeah, I look at the massive MIG welds all over that thing, and I'm like, seriously? Those 3 short "pot supports" up top only need to be simple L brackets instead of heavy steel, spot welded on instead of massively welded on each side.

Round is more material efficient though, and rolling it is probably easier than folding a box up.

Until you go to make the top and bottom caps. Then you either need to form a round flange around the perimeter, with all the shrinking (or relief notches/flutes) that entails, or make it out of much heavier material in order to avoid welding distortion. Also, while you lose some material efficiency by it being a box, you'll gain some of that back in reduced waste when making the top and bottom caps. And all of your cuts will be straight, lending themselves to shearing if you have a shear available.

[Netpackrat]

The REI crowd want a tiny one, which are even harder to make; though they're lower on materials at least.

Need to target the serious backcountry folks, survivalist, base camp hunters etc...

Also the REI people hate using wood because they actually have to get their hands dirty, and for some reason they think that using wood is "exploiting" the environment etc... etc...

Yeah, REI was just an example of a more upscale clientele, plus here in AK, anybody who wants quality gear shops at REI, not just the hippy granola mountaineering types. I was even in there myself a few days ago looking at something, before the smell of patchoulli and BO drove me out. Besides, even most of the hippy types aren't full on greenie; convince them that they are using wood in the most efficient manner possible, and a bunch of them will jump on it, especially people like canoe trekkers who can afford to carry a little more gear than a backpacker can. And hey, it's stainless steel and will last longer, and not find its way into a landfill. But some of the survivalist types, hunters, etc would be all over it too.

[Netpackrat]

However, I also have a plasma cutter, with enough juice to cut stacked material.

Shoot, you're golden then. Get/make one of those arm thingies (can't remember what they are called) that you mount the torch to, that you can use to trace a pattern. One of those things that people used to use for repetitive flame/plasma cuts before CNC.

[rightisright]

Need to target the serious backcountry folks, survivalist, base camp hunters etc...

That's what I was thinking. Something mid-sized (a 10" cast iron skillet would easily balance on) and well-made. Definitely not something to pack on a long hike.