I had this same thing happen to me with a 4" x 2" bushing stuck on a piece of 4 inch PVC. It helps to have 2 people to get it off. I just bear hugged the 4 inch as tightly as possible, and then my friend put a clamp on the bushing to get better grip, and pulled while twisting it back and forth.

I've heard you need an expansion chamber if you want to safely use Co2 in a cannon. Is that true? Because I've seen guns with and without such chambers running on regulated Co2.

If you live in Canada, call Princess Auto. The pressure washer handles in their catalog are 3/8"NPT inlet and 1/4" NPT outlet, pressures up to 5000psi . Prices range from 19.99 to 36.99 (watch you don't buy the "weeping" type) Be warned that is 5000 psi under water pressure which is different than ...

I spy with my little eye a quick disconnect which appears to swivel. If that's what it is, where did you get that because I could really use one.

Looks beastly. Except I'm kinda lost on how it works. Does it recycle its own air?

trae08 wrote:its midnight here i cant see...

Hmmm, your in my time zone then... what state are you in?

I was just thinking about this. Infact, I even posted a thread about "What to do with a Co2 cartridge?" and someone said make a launcher. Maybe it was you even, dunno. I'm definetly gonna make one next time I go to Menards to get parts.

I can worry about the relay after I get around the problem that the capacitor won't charge. Even when I bypass the relay, I get no current, and when I short the gaps of the capacitor, nothing happens, indicating that it isn't charged . If that didn't work, you have a faulty board probably. That's t...

My parents are the same way, they won't let me build a combustion gun, but they will let me build pneumatic cannons. (which I think are more fun anyway). My advice is that you just build a pneumatic, as long as you use pressure rated parts. Eh, combustions are cooler I think. And the weird thing is...

Mind explaining what a poppet is? Can't say I've ever heard of one, but I could just not be thinking tonight..

Wouldn't you have to have a PERFECTLY absolutley balanced rotor for it NOT to wobble going that fast?

Because if you got even the smallest wobble going at that speed, I don't think there would be much left of the object it would hit.

Thanks, I'll see what he has to say to that.

So how did you end up mounting these wheels? I actually used a strip of sheet metal about 1" wide, and about 10 inches long and bent it to form a U shape. I made two of those and mounted them on the end on the big timber supporting the cannon width wise. Then I just drilled a hole to fit the bolt c...

My dad believes that if I use propane or MAPP gas in a hybrid or even a simple combustion (PVC or steel or aluminum), and ignite it, the whole gun will explode into tiny pieces. Even if I use the reccomended amount of fuel for my size of cannon.

Anyone care to give evidence that he is wrong?

I don't have many, but here's some ok ones.