To reduce voltage, you use a step down transformer. This is the same sort of device used in AC adapters. One using the exact voltages you want may not be commercially available. You may be able to make one on your own, I've never done it so I can't explain how. Your best bet would be to just use a p...

1/2" marbles work in 1/2" PVC barrel...
What you described in the first post is very similar to the first pneumatic I built. Check out the link.
http://www.spudfiles.com/forums/tactica ... t8812.html
Here's a picture of it.

... are you kidding.
Read the sprinkler valve troubleshooting guide, it's stickied in the pneumatic cannon discussion section. I usually try to be nice about this sort of thing, but you didn't even need to use the search button to find what you need.

You could use a homemade scope mount like I did on my pneumatic. Here is a picture of it. http://www.spudfiles.com/forums/files/tms4_159.jpg If you want to try to replicate this type of scope I wrote a mini tutorial on how to build it at the bottom of the first page on this thread. http://www.spudfi...

ABS and Acetylene... talk about playing with matches.
Worst thing about that video was that it was built by a teacher...
I think I may email him or something. Thankfully nobody was hurt in the video.

calcium carbide isnt a solid propellent..it turns into acetylene when mixed with water...there were a few calcium carbide cannons on here... i left some nice comments on there :wink: d'oh! I'll admit defeat on that one... Forgot to do my homework on that one. All the same acetylene is nothing to me...

Calcium carbide is a solid propellant. In almost any country such a propellant would classify your gun as a legal firearm. We try to avoid discussion of lawbreaking here.

I think the bottle of propane might catch their eye before the silencer does. As far as what I've heard spudguns are legal in Canada as long as the muzzle velocity stays under a certain limit. Edit: Even if you enrich, you will have byproducts of combustion in your chamber. I would recommend you ven...

Manufacture eh? Just how many of these things are you going to build.

I agree with noname, enrich and die! (in PVC)

do you think i could make this out of pvc and use an electric motor instead? http://www.jockeyjournal.com/wp-content/uploads/2006/06/7d5d4410.jpg There I fixed it for you :) Edit: An electric motor may work, just what kind of electric motor are we talking about here. As for the PVC, I'm afraid it j...

Those two vid's aren't really related...
Either way both are good posts.
The guy in the first was just a fool, the cannon in frankrede's video is just amazing... but shh don't talk about it it's a calcium carbide gun.

I knew that link seemed vaguely familiar

You should be able to work it out from the link Gepard posted. Here is something to consider though. In the pictures shown at that link, you will see that I epoxy'd a nut into place... bad idea, it came out a few weeks later. I recommend you drill a hole right into the barrel where you intend to att...

This topic is pretty dead, but since you dug it up I'll throw in my thoughts. @Cannonball: If the propane in your bottle did liquefy it's volume would have been very low (tiny drops on the walls of the bottle), it's possible that the liquid propane remained a fine mist in the bottle. If the second s...

I'm in CA too, but I'm too flippin' busy getting ready for college and all to go to a meet.