Tuning FX Impact/Maverick/Crown brass regulator piston done right

Interesting design.
Seems to be a lot like the raw reg seat. Very easy to machine membrane and press in a new one.
They just drilled the air ways from the side though.



Want to add my two bits about reg recovery and creep.

Over the year I’ve spent days messing with expensive gauges and reg testers trying to figure out why some creep more that others. Basicly, it’s a delay in reaching the set point. Can be instantaneous, 1min, 2 min, 5min…30min or an hour. Or possibly even overnight.

I’ve concluded it comes down to how well the whole assembly was machined. Meaning how tight is the tolerable that mates the reg membrane with the brass air nipple.

Let’s just speculate u have a perfectly functional reg, but u go to adjust it 10-30 bar. If those two components aren’t perfectly matched up…there’s no way the reg will function the same as it previously did. As the nipple creates an impression in the membrane, and now this impression no longer matches up.

Ive concluded that some reg bodies just don’t work. I’ve never really gone through the effort of testing my findings with cmm measuring equipment…but maybe that’s the next step :)
 
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I haven’t shot neither of my impacts in at least three weeks, one of them over a month, and ever since I switched to a brass piston my regs stay put, exactly where they’re set at.

But, I still get the first shot slow on one of them, and on the other, first shot fast. After the first shot they are both back at their tuned velocities.

But I do agree, every gun will differ, no matter how identical I put one together to match another.

I’m just glad I don’t have to count to 15 before shooting the next shot in order to stay on group, like I had to before wiyh the plastic pistons. The plenum recovery is very fast.
 
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Interesting design.
Seems to be a lot like the raw reg seat. Very easy to machine membrane and press in a new one.
They just drilled the air ways from the side though.



Want to add my two bits about reg recovery and creep.

Over the year I’ve spent days messing with expensive gauges and reg testers trying to figure out why some creep more that others. Basicly, it’s a delay in reaching the set point. Can be instantaneous, 1min, 2 min, 5min…30min or an hour. Or possibly even overnight.

I’ve concluded it comes down to how well the whole assembly was machined. Meaning how tight is the tolerable that mates the reg membrane with the brass air nipple.

Let’s just speculate u have a perfectly functional reg, but u go to adjust it 10-30 bar. If those two components aren’t perfectly matched up…there’s no way the reg will function the same as it previously did. As the nipple creates an impression in the membrane, and now this impression no longer matches up.

Ive concluded that some reg bodies just don’t work. I’ve never really gone through the effort of testing my findings with cmm measuring equipment…but maybe that’s the next step :)
The sealing disk surface is critical for sure. Even the sharpest lathe knife cannot deliver the surface good enough. In addition to that the material removal speed during turning is lowest at the center of the detail giving the worst surface quality in the place which counts the most.
 
The sealing disk surface is critical for sure. Even the sharpest lathe knife cannot deliver the surface good enough. In addition to that the material removal speed during turning is lowest at the center of the detail giving the worst surface quality in the place which counts the most.
I’ve found what works best for me is a solid carbide micro boring bar.
Designed around Swiss lathe. I’m talking really tiny, the bar dia is .03” the actual cutting edge is razor sharp. What tiny pip is left in the middle is considerably smaller that brass nipple

I’m lucky enough to work around this tooling daily :)
 
So this is what the old one looks like when it's pulled out?
Guy made a cheap reg puller tool out of a ball point pen (y)
FX Impact/Crown Regulator Piston Puller Hi-Tech Tool (RPPT)
Screen Shot 2023-01-16 at 8.34.39 PM.jpg
 
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Nice job, we have done a bit with brass pistons and for sub 12 use we didn't see any benefit there was know disadvantage but know real improvement either this may be a different case in High power of course running much higher reg pressures, in sub 12 we have found to get the best out of the reg we re-face the adjuster screw and polish the tip of the piston, i still run the brass piston in all my FX rifles but more because i have them (y)

The pic is just some variations of what we tried
IMG_5874.JPG