ball bearing / marble piston

[spud-tom]

does anyone think that it is possible to make a coaxial with a marble? In my opinion, since it would be pretty heavy and it would rest on the pipe, as the air is pressurized, it would put the marble against the barrel - sealing it. Can you help me out and post some comment or ideas? Thanks.

[singularity]

there was a min coaxial "pen gun" that used an airsoft bb for a piston he won second place in the spud gun build off, check the spudfiles home page you'll see it

[spud-tom]

yea, i saw the post but didn't that guy say that he "thought" about putting the bb in, but to be safe he just went along with a normal piston?

[hi]

the bb is the piston. there is a gasket on the barrel to seal it.

to answer your question, yes, it could be the piston.

[spud-tom]

thanks guys, any ideas of balls bigger than a bb, smaller than golf ball - like a marble, but lighter

[VH_man]

www.mcmaster.com. search balls. youll find what youre looking for, garunteed. its where i get my steel 6mm air(hard) bb's. you can buy basically ANY size. find one that matches the ID of the tube youre using. i want to see this work, it makes sense that a ball would work well as a piston. never gets jammed

[jackssmirkingrevenge]

yea, i saw the post but didn't that guy say that he "thought" about putting the bb in, but to be safe he just went along with a normal piston?

I did this because my method of epoxy construction basically cannot be dismantled, only destroyed, so I figured I'd go with something I knew would work rather than experimenting.

If your tolerances were tight enough however I'm sure this would work well - you need to match your ball o/d to the chamber i/d very well though.

[hi]

would a solid rubber ball work? that way you wouldnt need a seal face because the piston is the seal face?

[jackssmirkingrevenge]

would a solid rubber ball work? that way you wouldnt need a seal face because the piston is the seal face?

Good idea, though it might cause problems in the long term as the rubber is always presenting a different face to the barrel edges which would cause uneven wear - but if you can access the ball and replace it this won't be an issue.

[pyromaniac]

what about a mouse ball in 3/4?

[spud-tom]

yea, i'm thinking of making a coaxial with a ball, (and making it fully accessible by just taking threaded pipe and sealing it with teflon tape) I like the rubber ball idea thought.


Merged:


what do you think about the Buna-N rubber Balls from McMaster?