Thursday, June 28, 2012

Fixing up the Backdraft


I'm still rooting around the Dungeon waiting for motivation.  My latest tangential project was to renovate my Heavenly Hobbies Backdraft.  This crazy rocket boosts on a 24mm motor and recovers with the help of a 24mm retro motor.  I have successfully  flown it four times.  Successfully in that the basic flight profile was sound.  On each flight, however, Kevlar tethers broke, parts were lost, etc.  On the last flight, the nose cone tether broke, possibly with help from the burning retro motor, and the tether on the plug that protects the 'chute from the booster section's ejection charge also snapped.  I found the cone but the plug was lost.  The fix was easy - tie a piece of nylon cord to the loose ends of the nose cone tether and replace the plug.  I made the latter from a piece of a spent 24mm motor and a plywood circle that came from cutting a centering ring.  Instead of attaching the new plug to an external tether, which is exposed to ejection gasses, I glued the elastic parachute shock cord to the inside of the plug.  I guess am ready to terrorize MDRA again :)