SpudFiles

i built these the other day with spare parts and epoxy. the larger one shoots marbles at pressures around 10-40psi, the smaller one is a coaxial that shoots airsoft bb's

the marble gun has a rubber catch in the back of the barrel so the marbles won't fall out, at 30psi it can put a quarter inch dent in my steel lockers.



this gun was also thrown together. i constructed the piston out of a half inch length of a small dowel wrapped in electrical tape with a neoprene sealing face gooped on. i have checked it for leaks under water and now it holds air perfectly. I have only taken it up to 30psi but i might take it to 50 or 60




this is my air compressor and tank, im going to get a regulator for the 11 gallon tank soon

OOoh ghetto, those look pretty fun, the only thing i can think off is change the bottle chamber to a coke one. Ghetto

cool but the bottle you chose looks like a cheap waterbottle, not only is the volume less than soda bottle but its not ment to take presure, but soda bottles are and can hold more presure, which is why I'm saving three 3liter soda bottles in my basement

how, far does you piston move back and what diameter pipe is that? ( the small one)

the piston moves like a quarter of an inch, the outside pipe is 3/4''

I will be the first to say that jb weld is terrible with plastic pipe.

benstern wrote:I will be the first to say that jb weld is terrible with plastic pipe.

It should hold at like 30 psi if he sanded his pipe. i wouldnt worry about it.

mopherman wrote:

benstern wrote:I will be the first to say that jb weld is terrible with plastic pipe.

It should hold at like 30 psi if he sanded his pipe. i wouldnt worry about it.

i was thinking about scrapping it but i just tested it up to 70psi and it held its integrity, so im going to keep it. i still not going to take it above 40

Looks like two nice cannons, but what is their performance like at the (comparitively) low pressures youre running them?
EDIT: very sorry, just saw my answer now (1/4" dent in locker)

i like small cannons. these are excellent examples of small cannons. keep up the excellent work.

homedepotpro wrote:i was thinking about scrapping it but i just tested it up to 70psi and it held its integrity, so im going to keep it. i still not going to take it above 40

now if you had used proper epoxy and technique, you could have happily taken it above 300

you are never going to be able to service your piston unless u cut off part of the chamber...

spudthug wrote:you are never going to be able to service your piston unless u cut off part of the chamber...

That's the eternal problem with my piston guns, however it does drive you do make designs that don't need to be serviced for the entirity of their useful lives.

oh I didn't notice before about the location of the schrader on the bottle gun, very cool I'm usally uneasy on puting schradders in bottlesthe schrader in the valve is pretty good maybe now I'll make a cannon with my 3 liter

spudthug wrote:you are never going to be able to service your piston unless u cut off part of the chamber...

i did, i had too. the first piston i made was faulty, but i got a coupling and put it back together.

oh I didn't notice before about the location of the schrader on the bottle gun, very cool I'm usally uneasy on puting schradders in bottlesthe schrader in the valve is pretty good maybe now I'll make a cannon with my 3 liter

yeah its one of those with a guide rod in it so it made it possible for me to put it there, which was handy when i used it for my larger coaxial.