co-axial questions

[super spuder]

well i am about to make my first co-axial, but i have a few questions first

#1 how far away from the barrel should the piston be when it is fully back?

#2 does the piston need to be completely sealed all the way around, cause i have a really nice hot glue piston, but it has a small leak around the side, could this work as an equalization hole?

i may have more latter, but that is all for now.

[jackssmirkingrevenge]

#1 how far away from the barrel should the piston be when it is fully back?

1/4th of the barrel diameter

#2 does the piston need to be completely sealed all the way around, cause i have a really nice hot glue piston, but it has a small leak around the side, could this work as an equalization hole?

if it's a small leak than the flow of your pilot valve then it should work

[Velocity]

1/4 is required for maximum flow. If I were you, I would step it up to 3/8 or 1/2, just because it can be difficult to get exactly 1/4, and if you do less, you lose power and flow.

[mopherman]

I too am making a coaxial and my piston keeps tumbling. i want to make a new piston, but do you think i could use a pad of duct tape for a sealing face? I heard someplace that as long as it has "give" it will work ok.

[super spuder]

use the rubber from an iner tube

[VH_man]

use that craft foam stuff you buy in miachels. works fine for me. just have to duble/triple it up so it doesnt burst.