Trouble with Huma Extra High Pressure Reg

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Apr 2, 2015
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Hey folks. Has anyone faced a problem with the Huma Extra High Pressure Reg for the impact ? Here is a synopsis of my problem. Not sure what’s wrong. 


I have the extra high pressure one which ranges from 135-200 bar. I’ve set it earlier at 140 and now at 150. The Reg has been broken in. Around 3000 shots. 

2. From the start the problem I’ve faced is that the first 4-5 shots are as much as 50-70 FPS lower than the FPS I have set it for. After the first 4-5 shots it settles and then shoots consistently at the speed I tuned it for. The problem is it only shoots consistently as long as I am shooting fast. The moment i take a break for a few seconds to reload a mag or aim a bit longer at the target than usual, the problem of slow FPS repeats. I wrote to Huma and they asked me to change the small valve delrin disk. I did that and it solved the problem partially for a few days. Only the 1st shot used to be low FPS. Rest were consistent. Now it’s back to the same old problem after say 200-300 shots. . It’s a bit irritating because you never know where your POI will land if you’re take a break while shooting and restart. 


It’s only when you are rattling off shots that they remain consistent. A few seconds break and the Reg acts like an old car which needs to be warmed up. Am thinking of shifting back to the original AMP Reg. It never gave me such issues. Have any of you faced this with the Huma Extra High pressure Reg for the impact ? Am I doing something wrong here ? 
 
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I would rearrange the Bellville washers for high pressure and see how that works out you'll probably never have to take your reg up to 200 i think the high pressure set up reg adjusts from 110 - 165......i think .... you'll have better results in that range
 
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20200920_141131.1600625528.jpg
I would rearrange the Bellville washers for high pressure and see how that works out you'll probably never have to take your reg up to 200 i think the high pressure set up reg adjusts from 110 - 165......i think .... you'll have better results in that range
Click to expand...

Thanks buddy. This is supposed to be the extra high pressure one which starts at 135 and goes till 200. I had set it at 140, then 150, then 155. But same problem persists. 
 
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I have a .30 and when I had the Bellville washers arranged for extra high my ES & SD was all over the place emailed huma and was told to add washers and set reg for high pressure haven't had a problem since

Click to expand...

This is interesting. Can you tell me a bit more of how many washers you added and in what arrangement pls. Also what Reg pressure did you set it up for ? Thanks in advance. 
 
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Sounds like your tuned on the DOWNSLOPE of the bell curve. Any slight creeping of regulators set point has the poppet being harder to open. ( all regs creep some )

HuMa less than most IMO. It is a TUNE problem and not a regulator problem from what I'm reading.

When the set pressure is too high for the hammer strike energy this is what happens.



add more HST or lower set point ....
 
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Sounds like your tuned on the DOWNSLOPE of the bell curve. Any slight creeping of regulators set point has the poppet being harder to open. ( all regs creep some )

HuMa less than most IMO. It is a TUNE problem and not a regulator problem from what I'm reading.

When the set pressure is too high for the hammer strike energy this is what happens.



add more HST or lower set point ....
Click to expand...

Thanks for sharing this. Interesting view point. Good learning for me. I’ve tried tuning at multiple speeds. From 750 upwards in increments of 10-20 FPS each time which is very small HST adjustments. Topped off hammer spring and even put the Reg at its minimum of 135 and upto 155. Didn’t solve the problem. 
 
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If the hammers weight is insufficient for the pressure being used nearly no amount of spring will help. In a PCP, higher the pressure becomes harder it is to crack the valve open let alone hold it open for sufficient dwell. There is a LOT of energy being absorbed by the poppet valve just getting it open, leaving what energy is left to lift it further and remain open allowing air to escape before slamming shut. Again higher the pressure harder it wants to reverse direction once opened and close !!

Higher power tuning near always requires more hammer weight used in a balance with spring energy that accelerates the mass of the hammer. Together they do the work required.

Heavier the hammer ( to a point ) the greater is its momentum & It will keep moving forward longer than a lighter hammer and then when it stops, accelerate in the other direction towards closing a tad slower. * This is how DWELL is created.



IIRC have read of hammer weights for IMPACTS ... Not an FX guy, so others may chime in on that.



I'm done being I'm not an FX tuner .. tho as a "TUNER" am well aware of the physics of which I speak.







All that said .... IF YOU HAD CRANKED DOWN on the adjustment bonnet to see where in bottomed out ? ... You FUBARED the seat which will cause set point creep.

The fix for that is flipping over the seat sealing disk.
 
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