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Winter Project

Posted: Sat Oct 01, 2011 8:32 am
by motorfixer1
With the arrival of colder weather I am thinking about building a new cannon. I was toying with the idea of making a scratch built piston valve with an aluminum piston and an all steel housing. I was thinking about a 10mm barrel for bearings. With an all steel housing and aluminum piston I hope to bring this unit to the 1000 psi range or higher. I have been searching for a few days and looking at the hpa pellet rifles for some ideas but that is as far as I've gotten. Any suggestions or ideas would be greatly appreciated.

Posted: Sat Oct 01, 2011 10:35 am
by Gippeto
You just want to build a piston valve gun for (safe) use at 1000psi? This can be done. :)

Aluminum for the piston will work, but sliding back and forth inside a steel housing will eat away at it...the debris won't be kind to your piston either. (look up galling)

Would suggest some form of wear sleeve. This is the piston from my co-ax, it has a nylon wear sleeve, and has been hollowed out and filled with a nylon plug.

Posted: Sat Oct 01, 2011 11:10 am
by motorfixer1
I was thinking of the piston floating on shallow gland o-rings. Maybe about .020" of actual outside clearance. Some sort of bumper will also be a big concern. What did you use for a pilot? I was thinking of some sort of electric solenoid valve, but the pressure ratings on those are pretty low.

Posted: Sat Oct 01, 2011 11:17 am
by Gippeto

Posted: Tue Oct 04, 2011 10:39 am
by velocity3x
This works well for me. It's gone to 1.2kpsi several times and shows no sign of stress.
http://www.spudfiles.com/forums/piston- ... 23060.html

Posted: Thu Oct 06, 2011 4:53 pm
by motorfixer1
I got a .45 cal Kentucky Rifle today for free from my dad. I am thinking of using the barrel anyone ever hear of doing this? I havent taken the thing apart yet to see what mods the barrel will need for attachment.

Posted: Thu Oct 06, 2011 8:23 pm
by Gippeto
Nice! :D

At any rate...please verify for yourself that it IS unloaded before mucking about with it.

There's a fellow in the showcase section using a muzzle loading barrel...has some pictures of how he attached it too.