Adding a Retainer to a Minimum Diameter Rocket

http://www.ApogeeRockets.com - A common problem with minimum diameter rockets has to do with holding the engine in during flight. You often don't want to add a screw-on engine retainer, because they are fatter than the diameter of the rocket, which would add a lot of extra drag. That defeats the purpose of minimum diameter rockets, which is to be low drag so they go extremely high. In this video, we'll show you an older technique that still works great on holding the motor in using a twisted steel wire rope that is buried under the fin fillet of the rocket. This was shown in the Peak-of-Flight Newsletter issue #95. It is easiest to put the wire rope on the rocket before adding fillets. But in this video, the rocket is already built, so we will have to retro-fit the rocket by cutting in some channels into the existing fin fillets. This involves using a rotary tool using a cut-off wheel. After the channel for the wire rope is cut, it will be bonded in place using thick epoxy. After the epoxy has hardened, the fillets are sanded again, and then re-painted.