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Blowgun-Triggered Piston Valve
Posted: Thu Jun 30, 2011 11:39 pm
by Jabingo19
I'm coming up with the basic concept of my next build, a more or less rifle-shaped golf ball gun, and I'm curious if with an efficient enough pilot area I can trigger the piston using just a blowgun and cutting out the unnecessary (in my opinion) cost of a sprinkler valve? Is it possible and I so how tough would it be? Oh and it's a 2" piston valve (contained in 2" tee)
Posted: Thu Jun 30, 2011 11:53 pm
by jackssmirkingrevenge
It depends how you're making your piston. Close tolerance (epoxy casting, machined, fitted with o-rings) is essential.
2" diameter piston piloted by a schrader, with the benefit of an o-ring seal.
Best thing is to
do the math, if you know the flow area of your blowgun and the inner diameter of your tee, you know how loose the piston can afford to be before it doesn't pilot.
Posted: Thu Jun 30, 2011 11:54 pm
by Gaderelguitarist
Some people on here have made pistons sensitive enough to be piloted by a shraeder valve. Blowguns are very doable. It helps if you have a lathe or drill press to make your piston.
I would suggest using a couple o-rings and a built in check valve in your piston.
Edit: JSR beat me to it by a measly second.
Posted: Thu Jun 30, 2011 11:56 pm
by jackssmirkingrevenge
Gaderelguitarist wrote:It helps if you have a lathe or drill press to make your piston.
... but
epoxy casting will give you just as close a fit
Posted: Fri Jul 01, 2011 12:00 am
by Gaderelguitarist
Epoxy casting would definitely be easier than machining a block of material to such a tolerance.
Jack, love your lathe as it loves you.
Posted: Fri Jul 01, 2011 12:06 am
by jackssmirkingrevenge
Gaderelguitarist wrote:Jack, love your lathe as it loves you.
I don't want to forget my
volkskartoffelkanone roots either and sound all high an mighty, machining tools are amazing but not essential to make a good quality high performance launcher
Posted: Fri Jul 01, 2011 12:42 am
by Gippeto
Sounds something like this one...
Entirely do-able. (click on the picture)
The link
http://www.spudfiles.com/forums/my-firs ... 12796.html
Posted: Fri Jul 01, 2011 10:04 am
by Jabingo19
Gippeto the design you linked is almost exactly what I'm doing... Which is weird. Anyways, I do have a lathe, on my older piston gun I bought two flat endcaps and turned them down, problem is that the ID of one of the pipes in my tee housing was actually bigger than the other, so it fit pretty loose at the bottom. But that epoxy idea is really good too, definitely going to make a hybrid PVC end caps and epoxy, thanks.