Tuning Avenger regulator - was newbie questions - now not so newbie questions

You probably should have left your gun alone for a bit. 250 shots is not enough to judge things unless you are experiencing massive reg creep. Now you have chewed up orings to deal with. That seat can still seal just fine the way it is but holy smokes, that’s a pretty deep impression for a new gun. Especially if you’re only set at 1,800psi. Looks to me like either that seat is just plain soft or someone turned the reg down under pressure. If not you, probably a hamfist at the factory. We can’t kid ourselves into believing that once the gun is assembled and shows 2,500psi on the reg, that the assembly line worker degasses the gun to turn it down. They’re pumping these guns out like madmen. No time for that. Some of the Avenger reg problems are probably self induced by the workers in their factory. Now that it’s apart, if you want to speed up your recovery time, there are a couple things you can do if you’re capable. Surface the outer edges of your washers with 1,000-2,000 grit depending how bad they look. Then polish your spool. I hope you remember the sequence of your washers.

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@Vetmx (or anyone else that has the experience): when you say "Surface the outer edges....with 1,000-2,000 grit....", do you mean to polish the contact edges of the washers? I have a granite surface plate, and the appropriate grit paper, and diamond lapping film....so lap the mating/contact edges of the washers with the paper on the plate, enough to at least remove the burs and get a bit of a flat shiny ring here --˃|)|˂-- and here (on the contact edges of the washers)? I ask because I did find a video of Ernest's where he tumbles the washers using a graphite media, to polish all surfaces, and another video shows someone polishing with some jeweler's paste, again polishing all surfaces. But it seems to me, and my ignorance, that the entire washer surface is not in contact with anything but air (unless the washers are completely compressed). But my ignorance tells me that the washer will never be completely compressed during normal service/use. If this is true, then I don't see any point in polishing anything but the contact surfaces. This is discounting the angular change of the mating surfaces, as the washers are compressed. Maybe there is something to gain by polishing all surfaces???

And when you say "Then polish your spool." does that mean the OD of the shaft that the ID of the washers are guided by? The washer ID is .250" and the shaft OD is .235". So .0075" clearance per side. Seems like a lot of clearance to me....so if the OD of the piston/shaft is what the spool is, and needs polishing, I guess I should be careful to only polish, and try to minimize removal of material?



Thanks for any clarification.

Correct, the important parts of the Bellevilles are the contact surfaces…the rim of the concave side and the crest of the convex side. 

Start by deburring their IDs. That is where the opportunity exists to chew up the brass spool as they cycle up and down. Then proceed with polishing the contact points.

Polishing the spool itself isn’t generally necessary unless it has a particularly poor surface finish, or if it has already been scarred up by burrs on the Bellevilles. Having said that, it’s pretty quick and easy to do while the regulator is apart so you might as well for peace of mind. As you noted, the washers already have a fair amount of lateral play but if you play with them and shift them to their worst-case positions, I think you will find they maintain more than enough contact between them to avoid influencing the stack height. So yeah, it’s a good goal to not take material off the spool when polishing it but it’s probably not a real problem in practice.

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Thanks for reducing my rambling down to the lowest common denominator. I tend to type a lot.

Thanks for the explanation, and thanks a ton for all the help (on here and on GTA).

I don't regret changing careers, but I do miss having access to machine tools at all times (I used to be a machinist/cnc programmer/manufacturing process engineer). I need a lathe. I'll try to make creative use of my wobbly drill press.

Polishing the reg piston and Belleville's contact surfaces went well.



Installing new o-rings, not going so good. Any tips and tricks for installing (and uninstalling) tiny 90 durometer o-rings? I have dental picks, and nylon picks but, these tiny o-rings....I don't see how to get them installed without a specialized tapered tool, made exactly for each o-ring.



I got the old o-rings out already but, I destroyed them, and scratched the brass (I polished it out)....but I'd like to avoid these scratches in the future.

I had to put my thinking cap on (which I haven't done in a very long time). I used a belt sander, hand drill, bench grinder, and various other crude methods to make an installation tool for the buna 005 o-ring out of a drill bit shank. Who needs a lathe? I won't lie, I do....but I got by without one, yet again.

And used a sliced off section of a gear oil nozzle for the larger o-ring.

She's on the bench, leak testing now. Thanks all that helped.