Somebody gave me some old E12 that likely had not been stored properly. Rather than build an expensive rocket to use them in, I am building a very cheap rocket. It will be using all found materials, the only purchased product I might use is a trash bag to make a parachute. In the photo you can see the main airframe which is a cut down Priority mail / Express mail triangular tube, a motor tube rolled from some brown paper using an empty E12 casing as a mandrel, a piece of D12 casing for a thrust block, a piece of cardboard cut to make a fin template, and some pieces from a cardboard cereal box cut and formed to make a pointed pyramid nose cone. I have to scrounge up another piece of cardboard to make some bulkheads and fins out of. I'm planning on building it with fins extended to the engine tube.
I did some crude modeling in Open Rocket to determine a ballpark size for the main tube and the fins. After I get more constructed I can take some weights to check stability margin. (I'm not sure if you can model a triangular airframe in OR so I modeled it with a round tube of the same cross section area, my triangle size is about equivalent to a 3" diameter tube.) I have a couple of E12-4 and E12-6. I think the size will be about right for an E12-4, E12-6 will deploy a bit lower but hopefully not too low.
I did some crude modeling in Open Rocket to determine a ballpark size for the main tube and the fins. After I get more constructed I can take some weights to check stability margin. (I'm not sure if you can model a triangular airframe in OR so I modeled it with a round tube of the same cross section area, my triangle size is about equivalent to a 3" diameter tube.) I have a couple of E12-4 and E12-6. I think the size will be about right for an E12-4, E12-6 will deploy a bit lower but hopefully not too low.