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Full Version: Anybody make 13mm piston kits?
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I’m thinking about NARAM-60 (and if possible some competition between now and then) and in looking at the events it looks like having 13mm piston launchers would be a good thing. I have some of the Sundward 18mm piston setups and could probably figure out how to make a 13mm version, but if there  are kits with the difficult bits already made I’d rather go that way and spend more time building (and practicing with) models.

Any ideas?
Hi Bernard.

I do not know of any 13mm piston kits, and do not have the Sunward kits.

Here is a  an article by Chan Stevens in the March/April 2009 issue of Sport Rocketry magazine:
Cheap and Easy Pistons for Dummies 

And another by Chan in Apogee's Peak of Flight  newsletter #374:
Build A Better Floating Head Piston Launcher

What I use for piston heads are K&S brand  1/2" diameter (O.D. ) brass tubing.  Cut to about 2", top end sealed with epoxy or resin.  inside part left hollow, sliding over a 3/8" dowel or stiff fiberglass tube if the piston head is going to have internal electrical contacts. And of course a stop ring glued to the bottom of the piston tube.

Maybe I should document a simple 13mm piston like that, with the ignitor wires external (internal is documented in Chan's  Apogee article). 

Certainly a lot of the National Rocketry Competition (NRC) events can make good use of a 13mm piston, not just NARAM-60.  Indeed five of the six of them are suited for 13mm pistons, exception being C Eggloft Alt.
Thanks, George. That will give me some things to think about....and some good ideas of things to build and practice with.