SpudFiles

Posted: **Sun Mar 31, 2013 12:43 pm**

How high of pressures? Would an average air compressor be fine?

Posted: **Sun Mar 31, 2013 1:58 pm**

My compressor only goes to 90psi, I feel comfortable with malleable steel(sometimes called blackpipe) at prob 300 psi. That stuff is cheap at homedepot, and usually prethreaded. I was actually kinda sore after putting a blackpipe spring powered ball valve gun together a while ago - you really gotta put your back into it while tightening.

Posted: **Sun Mar 31, 2013 10:02 pm**

Ok, so far I am looking at having a 5' long 3" PVC barrel and a 5' long 4" galvanized Steel chamber. What kind of power and range should I expect out of that?

Posted: **Mon Apr 01, 2013 8:13 pm**

Did someone say 3" barreled cannon?

[youtube][/youtube]

Sorry had to toot my own horn

Posted: **Mon Apr 01, 2013 9:25 pm**

That is the exact design I have been looking for.
does anyone know what valve they had on it?

Posted: **Mon Apr 01, 2013 10:49 pm**

Probably piston, its hard to see what that pull cord is attached to, so it could be a spool valve but i doubt it.

Posted: **Tue Apr 02, 2013 2:43 am**

It's a piston.

Posted: **Tue Apr 02, 2013 6:38 pm**

I originally built it with a 1" manually piloted sprinkler valve, when that failed I just through a spring loaded 1" ball valve with a string on it. It's probably fired close to 1000 shots by now and will most likely feature a viking funeral this summer due to so many thermal cyclings and UV exposure (it's been stored outside in NE USA for the last 3 years lol).

It was a fun gun, but PVC has it's limitations - mostly with regards to safety. My next 3" cannon will feature similar dimensions but constructed of heavy steel, featuring a road worthy trailer and gas powered compressor on board and designed for a 10X hybrid mixture

Posted: **Tue Apr 02, 2013 6:46 pm**

The first mac and beef shot was my favorite.

SpudFiles

Help with large 3" cannon