I am one of those people that really enjoy a bad joke, bad puns, and a creative play on words. In fact, in my home brewing and model rocketry, sometimes I enjoy coming up with names for my creations (with some obscure reference or bad pun) as much as I enjoy drinking the beer or launching the rocket. Earlier this spring I was watching a re-run of the Big Bang Theory and heard a great geek joke (I’d heard it the first time I saw the episode, but had forgotten about it), and through some weird series of tangentially related thoughts, I decided that “Incline Plane Wrapped Helicly Around an Axis” would be a great name for a rocket. Yes, I have decided that I am going to attempt to build a “screw” rocket, hopefully a single fin (that increases in width toward the aft) wrapped helicly around the body tube creating enough spin so that the combination of fin and spin will keep it stable. At first, I just kept the idea in my head and periodically pondered what obstacles I may run into during the build. Whenever I was in Lowe’s or Menards I would look around the different sections to see what might help overcome some potential problems in the build.
One of the first obstacles that I thought of...if the rocket is going to spin, I need to have the launch rod run through the middle of it. Which means I’ll need to build a cluster so there’s someplace for the launch rod to pass through. Considering I hadn’t built or launched a clustered rocket before and that was the FIRST obstacle I came up with, I decided to take a stepwise approach to this project:
Phase 1: Build a standard, non-spinning, clustered rocket. I figure if I can’t get a good launch from a standard clustered rocket, I have no business trying to launch one that spins and has fewer than the generally considered minimum number of fins.
Phase 2: Build a clustered rocket with three fins wrapped helicly around the body tube to create spin. The goal here is to have three fins so it should be stable on its own, but to see if I can generate a balanced spin. If that launches and recovers successfully, I’ll go on to Phase 3.
Phase 3: Build a clustered rocket with two fins wrapped helicly around the body tube. The idea here is to make any adjustments to the cant in the fins that may be necessary based on observations in Phase 2, and to see if I can create stability with just two fins. It may take more than one try to get it to work, and it may not work at all. If it doesn't, I guess I stop there and be happy with what I learned.
Phase 4: If all goes well in Phase 3, I will build a single incline plane wrapped helicly around the body tube that will hopefully, with the combination of the fin and spin, be stable. Again, observations from Phase 3 will be used to make any adjustments when I move on to this final step.