Short question topic

[wyz2285]

Well here is why I'm interested in it. Had a HPA system but I'm trying to ditch the tank.
So they are only using two o-rings too... Wonder if it's free float or snug fit?

[jackssmirkingrevenge]

Are you pre-pressurizing the ram cylinder? Have you tried chucking it underwater to check for the location of the leaks?

[wyz2285]

yes it needs a bit of pressure around 20 psi.
No leaks if the parts don't move... once it moves I loose 10 fps per shot

[jackssmirkingrevenge]

Some reading on dynamic seals.

You might be better off with an X-ring in this case.

[wyz2285]

Quick update: The seal got better after I used slightly larger o-rings.
So I'm gonna redo the aluminium part, make it squeeze the o-rings a bit, also gonna change the rear to thread mount instead of just o-rings slide on. If this works would be great, the thing is real crisp to shoot and quiet.
The articule says dynamic seals do leak, so what's the service time of a gas ram? Would be ironic since one of the main advantages advertised is no power lose over time compared to springs.

[wyz2285]

Well butter me rear and call me biscuit, I did not expect this [youtube][/youtube]
This would cause the need to increase the pre charge pressure and make the leak less noticeable.

[jackssmirkingrevenge]

Well butter me rear and call me biscuit, I did not expect this

Interesting find!

[wyz2285]

Diminished the leak, however the friction of the o-rings became problematic, the FPS actually rises a little when the pressure starts to drop before start diminishing.
FPS is also lower than the floating o-ring version, the piston is moving slower.

[jackssmirkingrevenge]

That Trump quote describes a good 70% of the ideas expressed on this forum, present company not excepted!

[wyz2285]

Meanwhile ordered a PDI spring and machined a carbon fiber+SS piston and bearinged guide, gonna compare the performance with the floating oring version.

[farcticox1]

Anybody tried building a piston compressor? I have a 2" stroke pneumatic cylinder rated at 250psi so was going to see if I could generate 200psi
[youtube][/youtube]

[jackssmirkingrevenge]

Honestly it's much easier to find a fridge compressor...

[farcticox1]

I did, it died

[hectmarr]

I did, it died

I also built it, and it also died!

[hectmarr]

Honestly it's much easier to find a fridge compressor...

I made one with a refrigerator compressor motor. Testing, it arrives without problems at 25 bar ... I exploded 4 mm polyurethane hoses. It really works.