Polishing FX AMP belleville washers....

[HogKiller]

Actually the question is two fold, is it a good idea to polish the Belleville washers in a AMP, or any other regulator, does it actually help? And two, what are the darn dimensions of them, I did something silly and reassembled mine before measuring them, anxious anticipation and itchy trigger finger. Oh sorry, it's a Maverick, details details.

Ah hah, got lucky, found part of the answer across the pond, 10mm od, 4mm id, .4mm thickness.

McMaster-Carr
Belleville Disc Spring
for 4 mm Shaft Diameter, 4.200 mm ID, 10 mm OD, 0.4 mm Thick

Part number 96445K197

Quantity 5 Packs of 12 each $3.63 Pack $18.15 + shipping

Why so many you may ask, well one...they are cheap and two, I've got 2 Mavericks for sizing and if I mess up the polishing, I'm good to go.

 

[bigHUN]

Yes, polishing the washers mating surfaces - where touching each other - is a best thing to do. Also polish those edges in the hole and outside, make a nice smooth radius. Make the faces shiny = minimize a friction between connecting surfaces - imagine they move/rotate in between along the time.
I don't think the stack was put together from multiple thicknesses, but more to do with orientation, like ()()() or (())(()) but for that you shall look up the diagram. I think whatever quantity of washers but shall start with inner edge |( and goes by )()()()( and finish again with inner edge )| ???
This was mine before I bought the oil-water separator for my YH compressor....

Also, when you have the Reg in parts, a best practice is to mirror polish the the two surfaces where the Reg breads. And when puting together don't lube just keep all dry.

 

[HogKiller]

Yes, polishing the washers mating surfaces - where touching each other - is a best thing to do. Also polish those edges in the hole and outside, make a nice smooth radius. Make the faces shiny = minimize a friction between connecting surfaces - imagine they move/rotate in between along the time.
I don't think the stack was put together from multiple thicknesses, but more to do with orientation, like ()()() or (())(()) but for that you shall look up the diagram. I think whatever quantity of washers but shall start with inner edge |( and goes by )()()()( and finish again with inner edge )| ???
This was mine before I bought the oil-water separator for my YH compressor....

View attachment 341223

Also, when you have the Reg in parts, a best practice is to mirror polish the the two surfaces where the Reg breads. And when puting together don't lube just keep all dry.

Thanks. I've seen the stacks ()()()()()( , mine was that way BUT others say )()()()()(), not sure it matters so I reassembled to the latter seems to be fine. I've got the new brass piece, not sure polishing that little Delrin center is possible, the other brass peice is crowned so I'm assuming that must be maintained to have as small a point of contact as possible. And just to make it even more fun, I'm going to polish the bottom of the large brass piece where the washer rests.

 

[nervoustrig]

For the washers, if they have a burr from the punching process, go ahead and knock it down. Both the ID and OD. If they have no detectable burr, don’t expect polishing to produce an improvement. But if in doubt, go ahead because it won’t hurt.

By comparison, the seat is usually where an improvement can be made. Not just FX regulators but regulators in general. Viewed with the aid of magnification, both surfaces should appear uniform (shallow conical in the case of FX) and smooth (absent any micro scratches).

 

[TDK]

I highly doubt you'll notice any improvement from polishing the stack.

Long story short, there is a chunk of oring put under the sealing grub screw that blocks off the angled manometer passageway on the M3 Impact. Mine had become lodged in the internal passageways of the gun causing slow and erratic plenum recharge times. I didn't know that till the very end, though. I did a deep dive into the AMP reg, had it in and out a million times cleaning and examining it. I also did a technical deep dive on belleville springs. I was convinced it was the spring stack, and I tried out different configurations (which didn't help obviously). In the end after blowing the oring chunk out of the passageway, and returning the washer stack to stock configuration it worked perfectly again.

On the subject of belleville springs, for starters you cannot get the correct belleville springs from McMaster. I ordered those same 0.4mm springs you list as a SOFTER option to try when experimenting. FX uses a mix of around 50/50 0.5mm and 0.6mm springs in a single stack arrangement (I was only able to find these spring from FX). Single stack arrangement offers the least friction and best performance which is why FX chose that. If you were using a different stack that had doubles in it, then you might see benefit from polishing. The reason for the mix of washer thicknesses, is that if you do design calculations on reg pressure and required spring force for reg pressure range of ~100 to 150bar it falls right in between a single stack of 0.5mm and single stack of 0.6mm washers. 0.55mm washers don't exist that I can find. Huma went a different route, and they send you a different washer stack depending on what reg pressure range you specify, however, the resulting reg pressure range is much narrower. FX chose a slightly unconventional arrangement of using a mixed thickness stack, but you know what? IT WORKS, and you don't have to change your washer stack out to run higher or lower reg pressures. If you were only running really low <80bar pressures, you MIGHT see some benefit from moving to a 0.5mm single stack. Similarly, if you were only using really high reg pressures, like >170bar, you might see a benefit of using a 0.6mm single stack. Over all, I don't think the juice is worth the squeeze chasing a customized stack unless you are running at the extremes.

The washer stack is 11 washers: ()()()()()(
I put the thin washers together, and then added the thick washers. From memory, it made sense to have the shoulder of the reg piston pushing against the I.D. of a washer due to diameters involved. (Also note, this is only for the second/final reg and should match for the Impact/Maverick, etc. The M3 first/bottle reg has different diameter springs in a completely different stack).

Polishing the air passageway sealing surfaces on both the piston and seat is a good idea. That should help with any creep you are having. It worked for me.

 

[HogKiller]

I haven't had any creep issues, I have been having, SUDDENLY a SLOW leak down 10 bar/hr even with some new parts it's happening, not as much as it was but still leaking down about 1 bar/hr.

Ok, out of a representative sample of 11, ONE of my Maverick regulators the range was from .37 to .56. I ordered 60 from McMaster-Carr, their range was much tigher with the majority in .36/.37 about 9 at .39 and some above .43, over all much tighter tolerance of the perfect .40mm. I've got a way to chamfer the ID bore a little bit and the wet paper for polishing and even some Semi-chrome if I want to get really polished to 5 rms, I'm guessing a touch over the edge, and I've got a leather strop with 3000 grit diamond, I use it for sharpening Katanas, and my kitchen knives. Tomorrow i'll be polishing 11 of them up and give the two mating surfaces a touch up with some fine paper on granite,.

 

[HogKiller]

Maverick Compact .22, Today had matched Bellevilles, I gave the washers a bit of a polish on all contact points and chamfered the ID;s on both ides a little. Polished up the contact points Net result, not a darn thing. The ONLY and i mean ONLY setting that was darn good gave me 872 fps with 18.13gr and a SD of 1.5, for some stupid reason I want to push them to 890. At both settings I'm getting 15 shots in a dime with friggin' gusty hurricane tailwinds at 30 yards.

 

[HogKiller]

Then there does not seem to be much of a point in overdoing it. May be keep spare pre built regs if needed- rather than expend elbow grease in the effort.

In the case of the Maverick, it's parts and o-rings. At least now, when I drop a darn Belleville washer I have PLENTY of spares.

 

[Airgun-hobbyist]

After noticing several gouges on the regulator piston, originating from the sharp corner edges of the hole of the belville washers, I rounded and polished the inside hole edges and also polished outer mating surfaces. With the older, smaller plenum it made a noticable improvement in tighter speeds once polished.

 

[HogKiller]

Could you perhaps point me in the right direction on what spares to stock for the maverick to keep her running? The only distributor is 500 miles away

I have enough o-rings to rebuild both of my Mavericks a few times over, I'll explain something in a bit. I have LOTS of the breech o-rings, I've found they come in different tolerances and you want 1% or Zero for those puppies. The kit from Capt. O-ring is ok BUT they only give you o-rings for ONE regulator, why you may ask...BECAUSE FX only shows one regulator on their schematic. HELLO FX, anybody home??? I have told Capt. about the issue if they've corrected it is unknown, I do know they didn't send me the missing o-rings. For the price of one kit, you can buy 10+ of every o-ring in the thing. Call me paranoid but it's cheap insurance, not that any of them are going to be going bad, they just sit there. Ok, the breech o-ring gets used and the regulator o-rings can fail. I've used The O-ring Store, Capt. o-ring and Amazon. Oh, under the gauges is what's called an X-ring, I've found and lost the source for them but they are available. There is also McMaster-Carr, I'm sure there are more. Beyond that, and a possible failed regulator not much to go wrong in my short experience.

 

[TDK]

Could you perhaps point me in the right direction on what spares to stock for the maverick to keep her running? The only distributor is 500 miles away

For o-rings, you can reference the FX diagrams and order from any o-ring supplier. These diagrams list 99% of the orings, but there may still be a few not shown: https://fxairguns-usa.com/available-parts/

As for the other parts...being in India, you won't be able to order from FX USA service center. I think you may have to order directly from FX? Best to contact your dealer or FX and ask them.

 

[bigHUN]

For the washers, if they have a burr from the punching process, go ahead and knock it down. Both the ID and OD. .........go ahead because it won’t hurt..........

I made a quick picture to people asking me how to polish the washer edges with these polishing bits, you can dress the shape to your needs...