Capture and Recycle The Hot Exhaust Gases
For Higher Rocket Flights

The purpose of a piston launcher is to provide an extra kick to the rocket as it takes off. It does this by collecting the exhaust gases from the rocket engine inside a tube. As the gases build up, the pressure inside the tube increases and kicks the rocket off the pad with a higher velocity. It is estimated that the altitude increase from this can be greater than 5%. That's not bad, since you don't need to change anything else with the rocket.

The Sunward Floating Head Piston Launcher kit contains everything you need to try this out for yourself. Just experimenting with the piston launcher is a great science fair project.

The YouTube video show above will show you how piston launchers work, and how simple it is to use them. They work so well, that modelers that compete in NAR rocket contests swear by them.

Previously, the piston head was glued onto the inner tube of the piston launcher, and this had one big negative drawback. It would stop the rocket dead cold. So all the velocity that the rocket had gained while the cylinder was filling up was lost. By making the piston head detached from the inner rod/tube, the rocket wouldn't stop anymore. The result is actually a higher lift-off velocity and a more stable launch.

Peak-of-Flight Newsletter #47 - This explains the basics of how piston launchers operate.

Apogee Technical Publication #11 - Piston launcher plans. These plans will show you how to build a deluxe piston launcher made for smaller rocket motors.

The Floating Head Piston Launcher - R&D report by Jeff Vincent, the creator of the first Floating Head Piston Launcher.

Empirical Evaluation Of Optimum Piston Tube Length For A Floating-Head Piston Launcher - Another R&D report by Jeff Vincent, the creator of the first Floating Head Piston Launcher.

The Sunward Piston Launcher Kit comes with three piston launchers (all the same size). Why three? Sunward felt concerned that they wouldn't last very long. I think they are mistaken.

The piston launchers will get sooty and dirty from the launch. But they are easily cleaned out after a launch. If you clean them good, you'll find that they do last quite some time. I've had one piston launcher that I used for about 10 years.

Therefore, having three for one low price is a very nice bonus. You can have three piston launchers ready to go, and you won't have to spend valuable daylight hours cleaning them while you are on the launch range. It will save you some time that you can be using to launch a lot of rockets!

The only drawback is that the thin-wall rings are a little brittle until you have them glued into the piston-head cylinder. Once they are glued in, they make a very lightweight piston-head that increases the efficiency of the system because the weight is reduced.

Tools needed to assemble the Piston Launchers:

• Wood Glue
• Sand paper
• 1/2 inch diameter wood dowel

The base is only needed if you are launching your rockets from a hard surface, like concrete or asphalt. If you are launching from grass, you will need a 1/2-inch diameter wood dowel to hold the piston in an upright position.

Q. How do you clean them out between flights?

A. I just sand off the soot residue with a piece of fine-grit sandpaper. For the insides of the tubes, wrap some sandpaper around a wood dowel so you can get down deep in the tubes. You want everything to slide easily with no gritty sounds.