The casing material is steel and pretty hefty, but should work well for this particular motor. I had to get a bit creative as each of the two sections was far longer than the bed of my lathe. It was fun and I ended up being pleased with the results. Here is a section of tube on the lathe and a nearly completed casing section for the SStS motor on my workbench:
I ended up with about four feet of tubing left over and figured that it should become a rocket motor :)My overall design was driven by the length of tubing that I had remaining. Here is the SRM output:
The casing has been completed and I've started cutting metal for the nozzle. I'm making the nozzle in two pieces, to ease the fabrication and to use metal stock that I had on hand. It's a pretty straight forward all steel design. The Divergent section is a little short with an expansion ratio of around 5.5:1, but again this was dictated by the metal stock that I had on hand. The downside is about a 02% reduction in the total impulse, but the upside is probably a six or seven hour reduction in fabrication time. I'll take it!
Everything else is being made with ease of fabrication in mind and I'm hoping to fly it this fall.
More to come...