Tuesday, March 2, 2010
The Thunderbolt 38mm Kit is finally on the way to being built. It took me this long because the snap ring retainer, a Gaint Leap slimline, was WAY too small for a fiberglass airframe. I estimated a full 1 mm ID too small. After much sanding by hand, I had to take it up a notch and use the Dremel, which still took about 30 minutes because (obviously) aluminum parts get VERY hot when machining. The part was finally able to fit (when hit on the top with a text book, invert. biology to be specific) and it is now curing with some JB weld. The extra JB can be seen curing in an old grape jelly lid; this is some great epoxy.
The sanding was harder for me than it would be for others with a proper rocket shop and some big tools, but around here it is a coffee table and Dremel. Having said that, this retainer does not seem right for this kit in fiberglass. It would be asking quite a bit for giant leap to pre-sand this part, but it would make this much more like a almost ready to fly kit, as advertised.
All this work is soon forgotten, however, as the anticipation of flying this rocket in April builds.
Next up will be the acme fin can, the hard point anchor, and final assembly of the airframe with a coupler at the center. With the purchase of some 30 minute epoxy, the rest of the rocket should be done within a week or so. Maiden flight will be a pro 29 G motor.
All too often, I find that my kits wind up full of minor mistakes or compromises. As part of my rocketry education, I hope to eventually build kits slowly and more carefully, and focus on the details.