SpudFiles

I was wondering If I could use a 3/16'' aluminum rod in a piston valve. I already have the rod from a previous project and it would be MUCH lighter than a solid piston. I'm looking at 2'' because i have a 1.5'' chamber and 1'' barrel and it would give me some wiggle room on size. BTW the check valve was out on the wrong design.


EDIT: I corrected the image

That's really thin for a 2" valve... I used 5/16 threaded rod in my 2 inchers and it is fine, but I'm not sure how much smaller you can go.

Yeah, I DO have a .25'' steel rod but that's ammo for my gun. I guess i can sacrifice 6 or 7 inches of it since it IS 2 feet long.

Your diagram looks good, you might wanna try the threaded rod piston.

3/16 aluminum rod seems a bit flimsy to me for a piston that large. It might work though, you can always try and then replace it if it bends or something.

Gun Freak wrote:Your diagram looks good, you might wanna try the threaded rod piston.

Thanks, I'm going to thread a steel rod I JUST found. It's precisely 0.311'' in diameter and 6.5 long.
Always happens, you find what you're looking for AFTER you stop looking for it.

All rod bending aside, you need to make sure there is enough bearing surface on the large end of the piston so that it will stay centred and seat properly.

You can also get rid of the bit of "inner" barrel which would give you some more volume and better flow.

Could you not fill from behind the piston ? Just cut a little groove to make the O-ring only let air through in one direction.

Does anyone have any ideas on making threading this stainless steel rod easier? I'm very limited on tools. (Vice-Grips, tap and die set, grinding tools)

Stainless is a bit of a ....female doggy to cut threads on with a die (or in with a tap). If you MUST...start it STRAIGHT, go slow, break the chips often, and use a quality tap cutting fluid intended for stainless.

Not sure what you have, but 300 series (common around here) stainless work hardens rather easily if you let it get too hot...usually a result of going too fast, or insufficient coolant. Keep it cool, and it machines beautifully.

A LOT less grief to simply go to the hardware store and get a piece of all thread.

Gippeto wrote:A LOT less grief to simply go to the hardware store and get a piece of all thread.

As much as I'd love to, I'm 17, broke, and unsuccessful at finding a job. minimizing cost is an absolute MUST.

Keep it cool, and it machines beautifully.

Yes it does. More reason to work with it! It's just BRUTAL work.

Piece of all thread=2 dollars.