FX What causes regulator to be same pressure as the rest of the air tube?
- Thread starter jem91
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This "current breed" FX owner found the AMP regulator in his "current" FX Bobcat had been thread locked by FX. So disassembly required application of a lot of heat. Then when his "current" Boss had issues rather than struggle with the thread lock bought 3 huma regulator and eventually replaced the AMP in all 3 FX.
The Huma is more easily adjusted with the pressure clearly marked on the body. There has been zero noticable creep on any of the 3 Huma regulator.
The Huma is more easily adjusted with the pressure clearly marked on the body. There has been zero noticable creep on any of the 3 Huma regulator.
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Yes, and this is why I noted that on air tube type guns like your bobcat I favor the Huma regs. I have Huma regs in both my wildcat MK2’s and on my Benjamin marauder, but on my wildcat mk3 “bottle” gun, my crown, and both my mk2 impacts I stick with the fx amp reg.
Just an fyi, on my wildcat MK2’s and almost every Huma reg I’ve installed on other people’s air tube type guns, that bar indicator label was off. I use a Huma reg tester tool to verify correct bar settings instead. The person that taught me how to work on fx guns told me to just remove the paper labels that Huma puts on their air tube type regs because some of the times they are off.
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Back to the OP’s dilemma about reg pressures matching up to fill pressures, when pulling out an amp reg for a reseal(I’m going to assume the fault is due to o ring failure and not piston seal. With piston seal failure most of the time what you’ll get is reg creep in a bad way)
make sure to change out all the regs o rings- that’s the one outside the main reg body, one inside the reg body, the one on the base of the piston, the two on the adjustment screw, and lastly, the one inside the reg tunnel. I blame this particular one the most when reg pressure matches fill pressure based on my experiences. If air seeps past that seal it bypasses the insides of the reg so it’s basically like not having a reg installed anyway. This o ring tends to dry up crispy like, and gets glued into the o ring groove, making removal a good test of your patience.
make sure to change out all the regs o rings- that’s the one outside the main reg body, one inside the reg body, the one on the base of the piston, the two on the adjustment screw, and lastly, the one inside the reg tunnel. I blame this particular one the most when reg pressure matches fill pressure based on my experiences. If air seeps past that seal it bypasses the insides of the reg so it’s basically like not having a reg installed anyway. This o ring tends to dry up crispy like, and gets glued into the o ring groove, making removal a good test of your patience.
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Tube or bottle is irrelevant, thread locker is relevant.
The markings get you close. Zero markings on the AMP. You have to write down how many turns when you disassemble.
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Hi jem91. As I said in my previous post (post number 19), the problem is that the O-ring on the set screw nearest to the piston needs to be replaced. Here is a thread that has a picture in the 1st post. In the picture you will see a set screw O-ring that has a red asterisk next to it. THAT is EXACTLY the O-ring that is damaged and is allowing air from your tank to go directly into your plenum. You need to replace that O-ring, but you should replace both of the set screw O-rings while you're at it. I see no reason to replace any other regulator O-rings unless air is leaking (you'd know if it was leaking because your tank pressure would drop significantly overnight or over the course of several days). I see no reason to buy a new regulator -- O-rings just need to be replaced sometimes.
FX AMP Regulator - Dreamline Bottle
Newman's video (910 Airgun Tuning & Repairs) on the AMP reg is really great. But it's fast. I usually need to put things on paper to memorize them. So, here is what I've just put together. Let me know if you see something that does not make sense. PDF attached, so if you want to print it...
www.airgunnation.com stovepipe
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I was mainly worried if the high regulator pressure would cause any damage but seems to be a common thing with time and use, Its an earlier model so those seem to have a few extra issues in general and some parts were updated later.
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History (feel free to skip to problem)
O.K. I am pretty sure I will get the same answer but I seem to be having a similar problem. I do have a couple caveats though. I bought a used an airacuda max to see if I liked the sport enough and I did. I am a physicist so I completely nerded out on tuning but hammer spring an pellet weight only since it has an internal reg. I had established that this would be a sport for me and so more research on guns to see what I wanted as I am leaning towards bench rest as I am also a disabled vet in a wheelchair so PRS is probably not going to be possible.
After searching I narrowed it down to a Skout Epoch, Daystate Wolf of some kind or an FX impact, King or possibly a Crown for the right price with the right barrels. I found a used Impact M2 sniper config with the 480 bottle and a .22 cal 700mm barrel. I plan on moving up to the power block and 720 plenum but I was shooting it daily on a 70 yard range I set up in the yard with retrievable targets on a cordless drill driven paracord rig.
I shot it for a few days shooting 14.3 grain exacts at 963 fps +-5 with hammer spring on max and a reg reading of about 105 and then moved to the 18.13 grain JSB's because I had better accuracy with them in my Airacuda Max and was getting great accuracy (for me anyway). with the external knob thing tightened to two about 2.25 lines except for the occasional flyer I was dropping 9/10 under an American quarter at the end of the range and had quite a few sub MOA at five shot groups that fit under a dime at 70 yards and 100 shot strings on a fill with +- 4 FPS.
Problem
But I knew I wanted to reach out farther so I decided to up the reg a bit. I turned it a quarter turn and it immediately went to 150 bar and I thought well, that is higher than I wanted to go as a first step but lets try it.
It shot at 750 fps now? And that was with the wheel at Max so I was puzzled. I though maybe I have a light hammer and it cant open the valve enough? So I went from 2 lines of the nob on the return spring (I think that is what it is called) to four and still no luck. so I pulled the bottle, degassed the plenum even though it made me a bit nervous as I was aware that this could cause problems with gaskets suddenly in a relaxed position after being under pressure for years.
And then no matter what I did the plenum went to the bottle pressure after that.
So is it reg rebuild time or should I just try to replace the set screw O ring first before bringing the reg all the way out for a full rebuild?
What do I need to do to take the set screw out after degassing? I saw the rebuild video for the M2 by AoA and they were taking the trigger apart and pulling the reg piston and stack out using compressed air that I don't have ready easy access to so if there is something I can try short of that I would like too.
And if I need too is there a way to get the stack and piston out wo using low compressed air? I mean I guess could use the can of computer dusting air for it unless I am told that that would be a bad idea.
It is an old gun, should i just get a new reg for it because this is likely to happen in the future and being efficient (read lazy) I like to make my future problems easyer to fix.
What say you Airgun Nation?
O.K. I am pretty sure I will get the same answer but I seem to be having a similar problem. I do have a couple caveats though. I bought a used an airacuda max to see if I liked the sport enough and I did. I am a physicist so I completely nerded out on tuning but hammer spring an pellet weight only since it has an internal reg. I had established that this would be a sport for me and so more research on guns to see what I wanted as I am leaning towards bench rest as I am also a disabled vet in a wheelchair so PRS is probably not going to be possible.
After searching I narrowed it down to a Skout Epoch, Daystate Wolf of some kind or an FX impact, King or possibly a Crown for the right price with the right barrels. I found a used Impact M2 sniper config with the 480 bottle and a .22 cal 700mm barrel. I plan on moving up to the power block and 720 plenum but I was shooting it daily on a 70 yard range I set up in the yard with retrievable targets on a cordless drill driven paracord rig.
I shot it for a few days shooting 14.3 grain exacts at 963 fps +-5 with hammer spring on max and a reg reading of about 105 and then moved to the 18.13 grain JSB's because I had better accuracy with them in my Airacuda Max and was getting great accuracy (for me anyway). with the external knob thing tightened to two about 2.25 lines except for the occasional flyer I was dropping 9/10 under an American quarter at the end of the range and had quite a few sub MOA at five shot groups that fit under a dime at 70 yards and 100 shot strings on a fill with +- 4 FPS.
Problem
But I knew I wanted to reach out farther so I decided to up the reg a bit. I turned it a quarter turn and it immediately went to 150 bar and I thought well, that is higher than I wanted to go as a first step but lets try it.
It shot at 750 fps now? And that was with the wheel at Max so I was puzzled. I though maybe I have a light hammer and it cant open the valve enough? So I went from 2 lines of the nob on the return spring (I think that is what it is called) to four and still no luck. so I pulled the bottle, degassed the plenum even though it made me a bit nervous as I was aware that this could cause problems with gaskets suddenly in a relaxed position after being under pressure for years.
And then no matter what I did the plenum went to the bottle pressure after that.
So is it reg rebuild time or should I just try to replace the set screw O ring first before bringing the reg all the way out for a full rebuild?
What do I need to do to take the set screw out after degassing? I saw the rebuild video for the M2 by AoA and they were taking the trigger apart and pulling the reg piston and stack out using compressed air that I don't have ready easy access to so if there is something I can try short of that I would like too.
And if I need too is there a way to get the stack and piston out wo using low compressed air? I mean I guess could use the can of computer dusting air for it unless I am told that that would be a bad idea.
It is an old gun, should i just get a new reg for it because this is likely to happen in the future and being efficient (read lazy) I like to make my future problems easyer to fix.
What say you Airgun Nation?
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I guess I am asking if I can just do this first and can I remove the set screw without messing wit the rest of the things you have to when you are taking the whole regulator out.
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Hi etothen. Yep -- now that you have removed the bottle tank and bled the air from the rifle, you can simply unscrew the regulator set screw all the way and pull it out. If the only bad O-rings in your FX AMP regulator are the ones on the set screw, then you can get back up and running by replacing those two set screw O-rings and replace the set screw -- no need to remove the whole regulator housing.
Edit: When I said "replace the set screw", I meant to just screw the set screw back into the regulator with the new O-rings on it -- not buy a new set screw. I figure you knew that, but I could see where my wording was not the best there.
The regulator set screw O-rings get cut and torn pretty easily compared to all other O-rings on the rifle IF one does a lot of regulator pressure adjustments while the gun is aired up. The invention of externally adjustable regulators is convenient -- but is frickin' torture for the set screw O-rings. Imagine airing up your Impact and, while still under pressure, you grab the quick disconnect part of the hose and spin it around without bleeding the line first. Yeah, that's basically what the set screw O-rings are experiencing sometimes. The only difference is that set screw O-rings are well lubed (hopefully).
stovepipe
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