Broken Arrow BuildFor my birthday, my wife bought me a Performance Rocketry Broken Arrow kit. The kit contains all fiberglass parts for an eight-foot tall, 4-inch diameter rocket.
No instructions are included, but assembly is straight forward. I began by cleaning a little flash from the large nosecone.
Next I added an eyebolt and glued the bulkhead into the nosecone's shoulder.
I drilled holes into one of the motor-mount tubes and screwed in a couple of brass inserts. I added a touch of epoxy to hold the inserts in place. A couple of screws and washers will be added later to complete the motor retainer.
I completed the motor tube assembly by gluign the three centering rings to the motor tube. Short pieces of masking tape were used to center the rings because the inside diameter of the rings was just a touch too large. I used a rotary tool to make a slot in the upper centering ring through which I threaded the shock cord. I tied the shock cord around the motor tube and secured it with epoxy.
I realized later that I probably should have waited to glue on the bottom centering ring until after the fins were added. This would have allowed me to make fillets where the fins contact the motor tube.
After sanding the centering rings to fit, I glued the motor tube assembly into the main body tube. Then I glued the fins in place. Once everything was dry, I made epoxy fillets between the body tube and the fins.
I made small pressure release holes in each body tube. And I drilled holes through the tubes into the electronics bay for shear pins and screws. I added 1/2-inch Acme conformal launch lugs.
I lightly sanded the entire rocket and painted it with primer then gloss black and red paints. The result looks impressive standing in our breakfast nook.
I didn't have to build an electronics bay since I already had a 4-inch one. Coincidentally, it's short length of body tube was already painted bright red which matches the new rocket's fins.
Additional build photographs are in the PayloadBay Gallery.
April 12, 2008: I flew the Broken Arrow using a J350 motor at the April NEFAR launch.
The flight was near perfect with the rocket soaring straight into the sky. At apogee (1750'), the drogue parachute deployed. The rocket fell quickly until it reached 700' when the main parachute deployed.
June 3, 2008: At the May, 2008, NEFAR launch, I flew the Broken Arrow with a camera mount I built for it. The camera mount holds two small video cameras. One camera is mounted so that it looks down the rocket. The other is mounted so that it looks straight out towards the horizon.
The flight was nice. The drogue parachute became tangled so the rocket was going a bit too fast went the main parachute deployed. This caused the nosecone to separate, but the rest of the rocket came down gently.
The video in the camera looking down the rocket stopped before the launch. I think there's a problem with the camera, so I am planning to replace it.
The camera looking out the side of the rocket captured the following video:
[Posted: 2008-03-08 | Updated: 2008-06-03]