SGT Rock's Wood Stove
I recently started testing the ZZ Manufacturing Inc. Sierra Zip Stove. It is a great stove, but it is too heavy and too large for true lightweight backpacking. But the design concept is very sound and is exactly what lightweight backpackers need. A simple stove that doesn't requires the user to carry any fuel, just use it as he goes along.
Trying to figure the weight efficiency of an alcohol stove vs. the zip stove, I arrived at the ideal weight of 4.9 ounces for the stove to be more efficient to carry for a lightweight backpacker. I also decided that the ideal bulk should be 3 1/2" tall by 4" wide, small enough to fit inside at .75L to 1L pot. It should be able to run off a small lithium battery.
My first experiment used a juice can as the outer air jacket, a spaghetti can as the burner chamber, some hardware cloth as the pot stand, and a 12v CPU cooling fan as the blower. It worked pretty well, but there were problems with channeling the air because of shoddy workmanship that required some metal tape to fix. Also, the 12v CPU fan needed 3 AAA batteries to get rolling, and 5 AAA to make a high speed for blowing. The total weight (without batteries) ended up at 5.3 ounces, and the dimensions were 4"x4". This was almost to my design specs.
Based on lessons learned from the experiment, I have drawn up beta 2.0 of the "SGT Rock's Wood Stove" for the lack of a better name. I haven't built it yet, but I decided to publish the plans so others can help experiment with the plans. My final stove design will be tested side by side with the ZZ Manufacturing Zip Stove in an upcoming trial September of 2001.
Step 1 - Gather Materials: You will need two cans. The outer can should be a minimum of 3" high and exactly 4" wide. The inner can will need to be at least 4 3/4" tall and exactly 3 1/4" wide. You will also need a 5v cooling fan (see Radio Shack), a lithium 9v, and four 1" wood/metal screws.
Tools you will need are metal sheers, a drill with a 7/64" bit and a 7/16" bit.
Step 2 - Make the burn chamber (Figure 3). Cut the inner can as shown, the 4 tabs should be evenly spaced.
The bottom should still be intact (Figure 1). Drill 8 evenly spaced holes using the 7/16" bit, centered 1" up from the bottom.
Step 3 - Cut the outer air jacket. Cut the can so it is 3" tall, then cut a 3 1/4" circle in the can bottom.
Step 4 - Make the fan hole.
a. Follow the diagram (Figure 6). Mark a pattern on the can as shown, 1 1/2" x 1 1/2".
b. Cut along the diagram as shown (Figure 7).
c. Fold the flaps up (Figure 8 & 9).
d. Drill starter holes (Figure 10). Drill one start hole with the 7/64" bit for the wood/metal screw. Put in the first screw, then drill the other three. Some bending with the pliers may be necessary to clear any fleshing from the fan. Don't tighten screws all the way.
e. Bend down the tabs to form an air seal around the fan (Figure 11).
f. Insert burner. Slide in from bottom, it should be tight.
g. Bend the tabs over as shown (Figure 4 & 5) to make the pot stand.
h. To use the stove, connect the leads to the 9v battery.
I haven't built or tested this stove, but based on beta 1.1, the stove design should work as well as a Zip stove and weigh about 4.5 ounces. Hope it works for you.
Update 23 SEP 2001
I have built a few versions of this stove, some are efficient enough to use. But I have decided that sticking with my Cat Stove is the way to go. With it, I only have to worry about finding some alcohol occasionally and have a light and eat stove. If you decide to build one of these, be my guest. For a better fan, try getting one from here.