Friday, June 05, 2009

"N" power without epoxy?

The typical Level-3 class rocket involves a lot of epoxy and fiberglass, Kevlar, or carbon fiber (or some combination thereof). I've heard of several examples. These are not well documented so I have no references.
  1. Although common in amateur circles, all-metal rockets are frowned upon in HPR circles. Both the TRA and NAR safety codes allows structural metal only where necessary to conform to the other provisions of their codes. But, these codes allow interpretation and some people have pushed the envelope. The owner of Dr. Rocket certified with, and sold, an aluminum rocket. It was built around the 4" AeroTech 'M' class casings, which were the used as part of the airframe. A special rear closure allowed a screw-on aluminum fin can and the upper aluminum airframe attached to a special forward closure. I forget what the nose cone was made from. After the good Dr. certified, TRA banned his kits from cert flights but not from use. The ban was not due to the metal but because the screw-together rocket didn't meet the intent of having the flier build the rocket. Since Dr. Rocket designed and built it, he was allowed.
  2. A flier at Delaware Tripoli (and often Maryland too) built and flew a 'M'/N' class rocket from 11.4" PML phenolic tubing (a Little John IIRC). This rocket was not glassed and the fins were screwed on with wood supports and molding 'fillets'. When I started this post I was going to say no epoxy was used. Now that I think of it, I only remember the fin attachment and things like couplers may have been glued in with epoxy. Close enough to meet the intent of the post. Kinda like the intent of using metal only where required. It occasionally suffered some damage on landing.
  3. Maryland flier Dave Bullis built an 'N' class rocket called Redemptive Power from construction junk and Liquid Nails. This flew successfully on an EX N4070 and IIRC recovered fine.
Anyone know of other examples? Anybody know if my memories are incorrect?