I just received a launcher and two screw-on fins sets from StratoFins. I had considered building a Clark cable tie launcher for some time but somehow never got around to it. So, when I saw one for sale, I couldn't resist. Another good toy for the grand-rocketeers!
I bought a mostly pre-assembled launcher because I'm lazy and I was hoping to use it this week. As it turns out, it arrived days early (ordered from Amazon) and the weather on the target launch day may not be conducive for water related sports. I will freeze here tomorrow tonight and we might even see some flakes. :eek:
The only assembly required was to screw the launch tube into the base. The PVC threads came covered with Teflon plumbing tape to eliminate air leaks. I test fit a fin unit and it seems to operate well. If you want to see how this type of launcher operates, I'll refer you to StratoFins' and/or AirCommand.
The four piece fin units are easy to assemble and appear to be sturdy. They screw onto standard soda bottles (2L and below, at least) and have a lip to mate with the launcher. The base of the hub also is threaded so it will mate with the quick-connect fittings that are used on the Quest water rocket launcher.
StratoFins also sells a parachute and describes an interesting way to connect it to a water rocket. Each pair of riser cords are looped over one of the fins. The cords are then brought together at the top of the rocket and are cinched with a cable tie. The 'chute is folded and set on top. A nose cone is made by cutting the top off another bottle. At apogee, the nose merely falls off and frees the 'chute. This almost sounds too easy and I'm wondering if the nose will occasionally (often?) fall off while the rocket is boosting. However, StratoFins offers a few videos of this set up working. I suppose I'll eventually try to find a mechanical timer to make a more positive release mechanism.