Re: 1322 PCP - the skeletonized valve doesn't leak anymore...

finally. What a pain. Lots of de-burring but the fix was using the right O-rings - cast urethane, size 013 to seal the valve with the tube (for the cut-out area). I also cut the o-ring grooves a little deeper... only a few thou

<img alt="[linked image]" src="http://i1249.photobucket.com/albums/hh5 ... ewa1dz.jpg">



Pumped it up - took 17 pumps to fill the valve. Before skeletonizing it was only 9. It's been holding air for two days now so I'm getting ready to tune and test. Thanks -

Wyo

Lots more volume is good. Yup right depth and width of cut to match the o-rings is a big deal and so nice when you get it right congrats. Makes me think I should fix the leak in mine but just got a couple new powder burners and have been saving .22 rounds for many years. So I have enough rounds to shoot for awhile months maybe even years? Can you say slacker? Actually like the song says I make them look like overachievers these days! So I am good for something anyway. ;^) Just not right now. ;^) Glad you got rid of the leaks I really hate them. Now I have to get back to slacking.

finally. What a pain. Lots of de-burring but the fix was using the right O-rings - cast urethane, size 013 to seal the valve with the tube (for the cut-out area). I also cut the o-ring grooves a little deeper... only a few thou

<img alt="[linked image]" src="http://i1249.photobucket.com/albums/hh5 ... ewa1dz.jpg">



Pumped it up - took 17 pumps to fill the valve. Before skeletonizing it was only 9. It's been holding air for two days now so I'm getting ready to tune and test. Thanks -

Wyo

Looking forward to test numbers.

finally. What a pain. Lots of de-burring but the fix was using the right O-rings - cast urethane, size 013 to seal the valve with the tube (for the cut-out area). I also cut the o-ring grooves a little deeper... only a few thou

<img alt="[linked image]" src="http://i1249.photobucket.com/albums/hh5 ... ewa1dz.jpg">



Pumped it up - took 17 pumps to fill the valve. Before skeletonizing it was only 9. It's been holding air for two days now so I'm getting ready to tune and test. Thanks -

Wyo

when you do the initial fill, and the recharge pumps between shots?

...and uses that as his "stop-pumping" pressure indication?

Lots more volume is good. Yup right depth and width of cut to match the o-rings is a big deal and so nice when you get it right congrats. Makes me think I should fix the leak in mine but just got a couple new powder burners and have been saving .22 rounds for many years. So I have enough rounds to shoot for awhile months maybe even years? Can you say slacker? Actually like the song says I make them look like overachievers these days! So I am good for something anyway. ;^) Just not right now. ;^) Glad you got rid of the leaks I really hate them. Now I have to get back to slacking.

don't want to 'skate' as well over the tube holes as the 3/32" CS o-rings.  Six total holes to navigate... I used this to help coax them thru:



Thanks -

Wyo

Looking forward to test numbers.

on the RVA. It's very sensitive... results below. thanks again -

Wyo

when you do the initial fill, and the recharge pumps between shots?

The pressure is indicated by setting the piston length to make contact with the valve. In this gun, it was when the forearm is 21 mm from closing. You stop pumping when the piston doesn't contact the valve.

The force on the piston, and the resulting strain, are directly proportional to the accumulated valve pressure. It works pretty well. I got the idea from Steve's "tell-tale" indicator. It's kind of spin-off, thanks

Wyo

finally. What a pain. Lots of de-burring but the fix was using the right O-rings - cast urethane, size 013 to seal the valve with the tube (for the cut-out area). I also cut the o-ring grooves a little deeper... only a few thou

<img alt="[linked image]" src="http://i1249.photobucket.com/albums/hh5 ... ewa1dz.jpg">



Pumped it up - took 17 pumps to fill the valve. Before skeletonizing it was only 9. It's been holding air for two days now so I'm getting ready to tune and test. Thanks -

Wyo

The extra volume did help, no doubt, but I'm now facing another reality... I think - small pump volume. There's probably only so much you can do with 1.1 cubic inch at 80% atmosphere. But still, it has better performance (efficiency) than anything else I've got... and with a 12" barrel.

 

With 4 recharge pumps it made 5.7 fpe, with 3 it was 4.7. The prior version (smaller valve) did 5.2 fpe with 4 recharge pumps. I am surprised and impressed with the ES and accuracy. It makes a nice 10m pistol.

Some other notes...I cranked-in the RVA as far as it would go and got 578 fps or 11.8 fpe from a full charge. It didn't empty the valve but I'm <strong>not </strong>going to re-spring to dump 17 pumps. I took a second shot when it was tuned for 4 recharge pumps and got 404 fps... 3 fps higher than the average first shot. That's pretty nice. There are lots of ways to tune these and I'm still getting my feet wet...

One more gratuitous pic (to make sure it happened) 



Wyo

don't want to 'skate' as well over the tube holes as the 3/32" CS o-rings.  Six total holes to navigate... I used this to help coax them thru:



Thanks -

Wyo

Even when one has removed the burrs from the holes on the inside of the tube they are still very sharp. I think it was TKO that suggested a Dremel ball bit, not the one pictured, but you get the drift, manipulated inside the tube till you can get the shaft out of the hole then twisted by hand to break the corners of the holes. A small screw with a countersink head and a piece of 400 or so sandpaper taped or glued to prevent slippage turned by hand or with a drill will do the same. I slacked and did not take the time to do this on my last project cuz I was in a hurry for some unknown reason so got the deserved results of the dreadful slow leakage of pressure from the tube. So being in such a hurry I just left it lay on the floor for the last two months while I pondered the reason for my existence. ;^)