SpudFiles

Compact 1" Diameter Co-Axial Gun

This cannon was built last year, it was my first piston valved cannon. At the time i had a large combustion and a large pneumatic, but i wanted something small, strong, and easy to fill with my hand pump. This cannon fit those all along with the price tag being below 50$.
I never used any serious ammo, mainly potatoes and airsoft shot, but today i saw it lying around and decided to make a "destroyer round" So after a little experimentation i found a projectile that flew well and left a mark.

Now for some specs:
fill valve - shrader valve

Pilot Valve - 1/2" ball valve

Pressure - 60-120psi

Bore size - 1 inch

Chamber diameter - 2 inch

And now for the part you all actually care about....
PICTURES!
The Full Gun:


The pilot/fill area:


0-100 pressure gauge:


Destroyer Round:


What happens when coffee can meats Destroyer Round:

Nice little cannon you got there
What is the piston?

the piston is the top of a spray paint can filled with aluminum foil and hot glue. The sealing face is four bicycle inner tubes bolted on, it works great

Wow man, pretty ghetto well at least it works good!

yea, i had a 1 1/4" coupling before, but it was too heavy and it broke itself (yea ik i should have a bumper) so i decided to go as light as possible

That's cool. I saw something like that on here a long time ago that had the ball valve spring loaded...

Thanks, im trying to incorporate a spring loaded system into a removable stock for this. I think it would help piloting, make a smoother trigger system, and it would look like a m79
but atm, i am finishing up on a silencer, and i hope to have pictures of it by the end of the day

Lolz I dont have a bumper in mine... Maybe I should make one

Me neither , but this piston weighs almost nothing. Making one should be as easy as shoving half a tennis ball in the back, but if your piston is light there is no need. If your piston is heavy, even though it hasn't broken yet, It stresses the launcher eventually to breaking point.

Yeah I'll think about it, maybe I'll add one next time I unscrew my chamber, because it had a PERFECT seal right now. NO LEAKS WHATSOEVER

Well I couldn't finish the main silencer, but the suppressed pilot valve and shoulder stock were added, Coming up: fully suppressed painted cannon.
Heres some pictures:
The Gun with the new attachments:


Close up on suppressor:


Super simple removable stock:

Looks good dude. That surpressor may be limiting the flow though, no?

i'm not an expert, this is my first pilot suppression, but how so?

Neither am I. The difference would be veryyyyy negligible. But it may be less rapid for the pilot volume to be exhausted to atmospheric pressure. But it should be fine.

ok, good. It helps A TON with the pilot noise, and is amazingly simple. I didn't plan for it or any thing, i just had a spare 1/2" pipe nipple and a 3/4" cap and some steel wool. I didn't notice any change in performance with and with out, but i was mainly focused on noised.