Wednesday, August 22, 2012

Two kludged-up air rockets

I wanted to try a few smaller air rockets but I didn't want to fiddle with a graphics program, didn't have plans for smaller rockets that would fit my 1" barrel and didn't want to buy more stuff to adapt a smaller barrel. So, I this is what I came up with.

The small one was based on a plan intended for a 1/2" barrel. For the body and nose cone shoulder, I merely cut the pieces wider than they printed.Yep, the other side doesn't have the nice printing. For the tip of the tube I cut a cardstock bulkhead. After it was glued in, the top of the tube was snipped to form tabs which it turn were glued over the bulkhead. I made the cone using's on-line template tool.   This was attached to a tube that slips over the body. The fins were designed and built on the fly.

The body of the long one was made from the core from a roll of wrapping paper. The rolled kind, not a tube.  I plugged it in the same manner as described above. The fins were also thrown together without any planning.  Once one was completed, I traced it and made two more. I didn't know what I did wrong, but the 3" cone I designed turned out to be too small in diameter. I could have crawled out of the Dungeon and re-run the numbers but began scrounging instead - a random clear tube, a ping pong ball, a short elastic cord and some twine. I ran the elastic out the top of the tube, knotted it and stuffed the ball snugly in. I epoxied the twine to the body and tied it to the elastic. The clear tube is very loose on the pressure tube and I hope it falls off as the rocket flops at apogee. I hooked on a parachute just in case it does. The odds that this will work is close to zero. If not, the ping pong ball will die and the 'chute will be returned to the range box.