SpudFiles

I was looking at copper for a couple of designs floating around in my head, but when looking at a decent sized gun(would want 1-2" barrel, and reducer to go from that to a 2-3" chamber/valve), the price of copper parts made me go Before I go looking at making my own parts oit of aluminum and brazing them on, I thought I'd see if there's anywhere worth looking. Furgeson and such have limited selection, the big stuff is hard to find.

It's copper, so it wouldn't suprise me if I'm barking up an empty tree, but I figured I'd ask before plunging into other options.

Yep, copper is pretty expensive. Places like McMaster rarely have the best prices but it'll take some legwork to find anything larger than 1" locally.

What type of cannon is it?

A combustion and a pneumatic. I actually sketched out the piston valve so the pilot is off to the side, ideally this would make it made out of smaller plumbing parts so fewer big pieces would be needed.


I feel more comfortable with metal than with plastic, but steel pipe has the seam, and so doesn't make a good barrel or valve housing. It sounds like estimating how much it would "cost" to make the aluminum parts would be worthwhile.

Epiphany for combustion designs at least, solder to npt adaptors aren't too much, so I can use a smooth copper barrel, and cheaper(and incidently stronger) steel for the chamber.

For pneumatics it's still square one. I'd like a design I don't have to machine on. That means finding a decent part to use for the main valve body that's smooth enough for a piston that can be connected to the barrel without a 75-100 dollar part.

IIRC some builders are sanding out the seam... I can't remember if I have done that but was going to when I get some time off, using a dowel and sandpaper. Slitting the business end of the dowel would allow shims to be inserted, sort of like old school rifling tools. Smaller pipe would also work instead of dowel but shimming gets creative