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filling a piston

Posted: Sat May 23, 2009 8:35 pm
by covey12
is a rapid amount of air need to fill a 2" piston, because i have the feeling my bike pump is not putting out enough air to even push the piston, should i save up and get a cheap compressor?

Posted: Sat May 23, 2009 8:42 pm
by spudtyrrant
i have used a bike pump to fill up my 2 inch piston cannon maybe you piston isn't tight enough add some teflon tape around it and try again :wink:

Re: filling a piston

Posted: Sat May 23, 2009 8:43 pm
by Technician1002
covey12 wrote:is a rapid amount of air need to fill a 2" piston, because i have the feeling my bike pump is not putting out enough air to even push the piston, should i save up and get a cheap compressor?
A smaller EQ port or a better seal is required. Until 2 weeks ago, all my cannons were hand pumped. My hand pump died and I bought a very small compressor for $60.

Could you post details on the 2 inch piston cannon? How is it sealed? Is it filled through the pilot? Photos are helpful.

Attached is a photo of a 2 inch piston under pressure test with a hand pump.

Problems with the piston sealing face can also prevent filling as the valve will fail to seal against the barrel. What are you using for a seal? Is the valve seat true and polished flat?

Posted: Sat May 23, 2009 8:50 pm
by covey12
yea i did have quite a bit of clearance around the piston now that i think about it, probably about .5mm from the piston to housing, is that to much? it is barrel sealing t-piston

btw on my new piston if i just put screws threw the tee and the end cap will it be air tight, this way it will be serviceable

Posted: Sat May 23, 2009 9:13 pm
by Gaderelguitarist
To use a hand pump with that piston you could easily put a light spring behind the piston.

I don't even bother with trying to make socket fittings serviceable. It's caused me too much wallet ache in the past. But don't let that discourage you. It does work, it's just not for me i guess.

Posted: Sat May 23, 2009 10:03 pm
by jmccalip
Well, my 3" piston uses a homemade check valve, and that seems to do the trick. I have not tried it with a bike pump, but it can fill with almost no flow(I used a air regulator).