Help plese

[Packols]

2 days ago i make a pneumatic pen gun using plastic pen for the body and the eraser and a piece of rubber for the piston for the shredder valve i use a valve from bicycle. i glue everything with 5 min epoxy and also use a super lube lubricant . when i pump it to 90 psi(that's the limit of my pump) i take it out and when i shoot it gave a very quiet sound like pss and its not even enough to pull the piston back there was no leaking on the gun i don't know about the pump. does anyone know why? is it my pen gun or the pump that have the problem. Thank you very very much )))))

here's the video http://www.youtube.com/my_videos_edit?n ... =my_videos

[jackssmirkingrevenge]

As explained in your other thread, the problem is probably the piston. The outer diameter of the piston needs to be almost exactly the same as the inner diameter of the chamber.

[Packols]

thank man is it good for me to make the piston out of glue gun and i think to make one out of a copper pipe i wonder if i put the glue gun in and let it dry how could i get it out i already try but cant get the glue out