Finally, 4SPC completed (4" Sweet Piston Cannon)
Posted: Sat Apr 19, 2008 4:20 pm
I know i havent been posting frequently, but i have been just lurking, finding the right moment for me to post a comment. But im still here 
Well i finally got my 4 inch piston cannon completed. It was a big project, but i managed to get it done. All my parts are pressure rated, but i have my concern about the pipe because i saw some lines on the pipe and i dont know if those are possibly stress lines, so i will take a picture as soon as i get the camera from my mom.
Enough rambling and on to the Specs:
Pilot: 3/4 inch QEV from mcmaster piloted by a 3/4 inch ball valve
Piston: 3 inch endcap
Sealing face: 1/8 inch thick neoprene from Mcmaster
Barrel: 3" 10'
Chamber: 4" 8'
My fittings are mostly from Sprinkler.com except the 4x3 bushing, which i screwed up the first time, so i bought it from Mcmaster.
She gives nice recoil at 30 with no barrel.
I have used my cannon a little and it was good, but i still have some problems to fix and some things to finish.
I need:
a barrel support
a breech loading
something to support my sealing face
paint it
name it
I have used my gun to 60 psi, and its pretty powerful, but i havent been using ammo that completely fits 3", but that wont be a problem as soon as i make some pykrete.
Since my piston is an endcap, and the face is rounded, i need to make it straight, so that my piston wont leak. So i at first had a 4 inch OD grinding wheel, which didnt last long because when it would slam against the barrel to seal, it would start to break, until one side was just completely broken. So that was removed and i tried it without. Worked fine, until 30 psi, where the sealing face passed the ID if the barrel and it would release the air.
So my question is, which washer would be good enough for a something to support my sealing face, where in the presence of force would not bend nor deform?
Would this be good? 91117A260 on mcmaster
Pictures are not possible now due to the lack of a camera at the moment, but will be here soon.
EDIT:

the cannon

Pilot setup with a 1/4 cross from mcmaster

3" 10' barrel

Front of piston

Side of piston

Back of piston

Comparison from small piston tee gun to my big one

Broken grinding wheel that was my sealing face support
So what do you think? I have a question but i forgot it, if i remember ill edit.

Well i finally got my 4 inch piston cannon completed. It was a big project, but i managed to get it done. All my parts are pressure rated, but i have my concern about the pipe because i saw some lines on the pipe and i dont know if those are possibly stress lines, so i will take a picture as soon as i get the camera from my mom.
Enough rambling and on to the Specs:
Pilot: 3/4 inch QEV from mcmaster piloted by a 3/4 inch ball valve
Piston: 3 inch endcap
Sealing face: 1/8 inch thick neoprene from Mcmaster
Barrel: 3" 10'
Chamber: 4" 8'
My fittings are mostly from Sprinkler.com except the 4x3 bushing, which i screwed up the first time, so i bought it from Mcmaster.
She gives nice recoil at 30 with no barrel.
I have used my cannon a little and it was good, but i still have some problems to fix and some things to finish.
I need:
a barrel support
a breech loading
something to support my sealing face
paint it
name it
I have used my gun to 60 psi, and its pretty powerful, but i havent been using ammo that completely fits 3", but that wont be a problem as soon as i make some pykrete.
Since my piston is an endcap, and the face is rounded, i need to make it straight, so that my piston wont leak. So i at first had a 4 inch OD grinding wheel, which didnt last long because when it would slam against the barrel to seal, it would start to break, until one side was just completely broken. So that was removed and i tried it without. Worked fine, until 30 psi, where the sealing face passed the ID if the barrel and it would release the air.
So my question is, which washer would be good enough for a something to support my sealing face, where in the presence of force would not bend nor deform?
Would this be good? 91117A260 on mcmaster
Pictures are not possible now due to the lack of a camera at the moment, but will be here soon.
EDIT:

the cannon

Pilot setup with a 1/4 cross from mcmaster

3" 10' barrel

Front of piston

Side of piston

Back of piston

Comparison from small piston tee gun to my big one

Broken grinding wheel that was my sealing face support
So what do you think? I have a question but i forgot it, if i remember ill edit.