HeavyLight
Well-Known Member
- Joined
- Jul 11, 2013
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- 175
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So I've gotten very enthusiastic about this once I started drawing it up. I was thinking about something to start working on that can be used as a good L2 rocket. It's a 4"/54mm scale BBIII; the scale ratio being about 1/2.6. It presents some unique problems in regards to some of the parts and the fact that I want to keep it on a budget. The airframe is going to be made of phenolic because fiberglass is really expensive and according to the FAQ at PML phenolic will do for flights that don't intend to go trans or supersonic. As it stands, this is designed for high H through probably low and mid K motors and goes Mach 0.8 at best. It's also over-stable because the only conical nose cones out there that I could find are made of fiberglass, which brings the CG forward significantly. To fight that I originally wanted to make the nozzle bell out of aluminum but then I read the TRA rules that said metal can only be used to ensure structural integrity (at least that was my understanding). So I changed the material to acetal a.k.a Delrin. I want it to be like the Estes model in that it has a shoulder that fits into airframe. It still has a lot of work to go before it's ready but I've got plenty of time and a huge community of rocketeers to help me.
View attachment BBIII.ork
View attachment BBIII.ork