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Unread postPosted: Sun Aug 12, 2007 7:17 am
Author: dongfang
Hi,

Yes, I have added the valve to a cannon. That's why I have been away for a few days - my shooting range is 1200 km from my home :o

It triggers my gun to a much more powerful shot than my RainBird and blowgun assembly (but the blowgun is on a hose - it might have some improvement potential). I can really recommend trying to build one, for anyone who is not sure his/her piston valve is performing optimally.

There are 2 little flaws in the design (the valve on the pictures): At > 6 bar / 100 psi, it blows the o-ring off the pull-out piston. The piston should be made a little longer, or a larger o-ring should be used. And, when firing it with a good, hard pull on the cord, sometimes I pull the whole bolt out of it, and ruin the return spring. A stop of some kind should be added.

Again, this valve was only a substitute for a miniature DFTV (Darn Fast Turbo Valve, a 3-disk valve that was designed by someone else, a long time ago) to use as a trigger. The DFTV would still have been nicer.

Regards
Soren

Unread postPosted: Sun Aug 12, 2007 10:09 am
Author: spud yeti
Hmm, a stop does sound good to retain the bolt. Perhaps a disk with lots of holes in it would work the best?

Can you not cut the O-ring groove deeper and use a thicker O-ring? Or epoxy it in :D

It sounds really great though, and I wouldnt mind seeing a setup of the whole cannon some time.

Unread postPosted: Sun Aug 12, 2007 11:40 am
Author: Modderxtrordanare
I was going to say superglue the o-ring in and that should solve it slipping at 6bar+