Brief:
I build Crayon rockets. Seriously. I get the big Crayon coin banks from Toys R Us, and turn them into high-power rockets. I have a 38mm, 54mm tube-fin, 38mm 2-stage, and 38mm cluster version. I also have a 54mm 3FNC version that's under repair. So that's the family. I had someone who knew of my crayon fleet give me a purple bank to use. I decided to build a rocket for a proposed drag race at LDRS 28.

Construction:
The first problem is that the crayon tubes aren't a standard size. The ID is 3.75", so if you get 4" centering rings you need to sand them down to size. I epoxied my sanded rings to a 38mm MMT and attached the fins to build a basic fin can. I then cut the slots for the fins.

After epoxying the fin can into the tube, I also epoxied a bulkhead into the nosecone to connect the chock cord. Since the nose of the crayon bank is plastic, I had to rough up the plastic so that the epoxy would bind. I added a little nose weight in the form of an ounce or two of BBs.

Flight and Recovery:
Since there's no electronics bay, I just use motor deployment for the chute. The drag race at LDRS never came about, but I flew it anyway. The first flight (July 3) on a G185 had me worried as it arced over the crowd and headed down before the chute finally deployed. The next flight the next day was on a G79ss with a 4 second delay. That flight went beautifully! Deployment was right at apogee.

The next flight, on July 19, also had a 4 second delay, but the chute deployed as the rocket was still going up. I'm not sure why that was a problem on the same motor (G79ss). It caused a small zipper of about 1.5 inches but nothing serious. It flew again a few weeks later. Welcome to the family!