This rocket is made almost entirely of polyethylene. Other materials include a 6061 aluminum motor retainer, and stainless threaded rod.
The rocket will weigh ~50# loaded and fly to ~7000feet powered by an Aerotech M1315. I chose polyethylene because it's really hard to break. I think you would have to get it around -60 deg F. before you could fracture it.
The tube is molded LDPE. The tubes are molded by Ideal for bollard covers. The thickness is .2-.25". I just cut them up and removed sections to make couplers and weld them back together.
The fins and bulkheads, etc. are 1/2" HDPE sheet.
Everything was done with table saw and routers.
The welding is standard plastic welding:
I use a Kamweld or Leister welder. The units use electricity and shop air to provide heat and welding rod of the same material you are joining.
I build plating lines so I'm pretty familiar with different plastics and fabrication techniques.
Polyethylene is approximately .92 g/cc
I probably could use smaller thicknesses but we will see how this one goes first.
Oh yeah, on the fracture concern...
For a rough material test, I cut a 15" length of HDPE 1/2" x 1/2".
I put one end of the strip in a vise and beat the heck out of the other end with a big hammer.. Result: a little dinged up and slightly bent.
Pretty scientific, huh?
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