Will a malfunctioning regulator cause point of impact changes ? When I fill my leshiy classic to 250 bar, the POI is an inch and a half low for the first few shots.
Tuning Bad regulator?
- Thread starter Woodsie
- Start date
Is regulator creep something I should be concerned with? This is my first pcp with a regulator.
Upvote 0
If it’s for target shooting exclusively, just do the dry fire thing.
If you plan to hunt with it, yes it is an issue you’ll want to address. Sometimes it is as simple as getting the hammer spring tension adjusted properly. Gradually increase the hammer spring tension until the velocity no longer increases, then back it off until the velocity falls to about 97% of that maximum. For example, if the max velocity is ~900fps, reduce the hammer spring tension until the velocity falls to 900 * 0.97 = 873fps. That will put the gun at a state of tune similar to an unregulated PCP operating near the top of its bell curve…meaning a varying pressure will have very little influence on the velocity.
If that doesn't remedy it, you will need to address the creep at its root cause. Creep is caused by surface defects in the regulator's valve seat. That causes the pressure to rise up most of the way but then a small amount of air will continue to weep through the surface imperfections over a period of minutes or hours until it finally rises high enough to totally squish the valve seat together and completely halt the flow of air. So the cure is to dress the valve seat smooth with an abrasive or replace it if that is an option. If it is a simple geometry, you can use fine wet/dry sandpaper to dress it to a smooth finish. If it is a tapered or convex seat, an abrasive compound (paste) can be used to burnish the mating surfaces together and bring them into an intimate fit.
If you plan to hunt with it, yes it is an issue you’ll want to address. Sometimes it is as simple as getting the hammer spring tension adjusted properly. Gradually increase the hammer spring tension until the velocity no longer increases, then back it off until the velocity falls to about 97% of that maximum. For example, if the max velocity is ~900fps, reduce the hammer spring tension until the velocity falls to 900 * 0.97 = 873fps. That will put the gun at a state of tune similar to an unregulated PCP operating near the top of its bell curve…meaning a varying pressure will have very little influence on the velocity.
If that doesn't remedy it, you will need to address the creep at its root cause. Creep is caused by surface defects in the regulator's valve seat. That causes the pressure to rise up most of the way but then a small amount of air will continue to weep through the surface imperfections over a period of minutes or hours until it finally rises high enough to totally squish the valve seat together and completely halt the flow of air. So the cure is to dress the valve seat smooth with an abrasive or replace it if that is an option. If it is a simple geometry, you can use fine wet/dry sandpaper to dress it to a smooth finish. If it is a tapered or convex seat, an abrasive compound (paste) can be used to burnish the mating surfaces together and bring them into an intimate fit.
Upvote 0
Very good info thank you! I do use the rifle for rats and occasionally squirrels and have the hammer spring dialed way down to help prevent pass throughs. I'm using the. 25 barrel currently and believe the regulator is set at 120 bar. Should the regulator be set lower?
Upvote 0
Hi I have a leshiy with geeze like 75k shots threw it , I never had a bad regulator seat fail on a edgun , I also have 4 other edguns and I accually never had a regulator fail , I have had issues with regulators like one time a oring shaving blocked the feed port or some times orings fail and they leak or cause like what you have , it is easy to fix ,
Also what fps or fpe are you running ? and is yous 250mm or 350mm ? and is it a stock edgun regulator or a huma , I do run 3 different ones on my leshiy , say I shoot .22 cal and I need sub 12 fpe I will install a huma with a small plenum and get tons of shots or I set it up with a huma and large plenum and shoot slugs or 25 cal , as this one give me extra shots over EDS , it is not better but because it is smaller in size the tiny tube holds more air to use ,
Soi as you said you shooting low power , so it depends on how low you shooting before you need to use the sub 12fpe kit , this is why I asked also how many shots you getting this can tell me how you got it tuned ,
PM me if you cant get it rite I got both reg testers and stuff
LOU
Also what fps or fpe are you running ? and is yous 250mm or 350mm ? and is it a stock edgun regulator or a huma , I do run 3 different ones on my leshiy , say I shoot .22 cal and I need sub 12 fpe I will install a huma with a small plenum and get tons of shots or I set it up with a huma and large plenum and shoot slugs or 25 cal , as this one give me extra shots over EDS , it is not better but because it is smaller in size the tiny tube holds more air to use ,
Soi as you said you shooting low power , so it depends on how low you shooting before you need to use the sub 12fpe kit , this is why I asked also how many shots you getting this can tell me how you got it tuned ,
PM me if you cant get it rite I got both reg testers and stuff
LOU
Upvote 0
Yes if you back off the hammer spring too much, two negative consequences are likely to arise:
1. The gun will be more sensitive to pressure creep.
2. The extreme spread will be sub-optimal (even if the regulator doesn't creep) because the gun will be operating somewhere on the spectrum of valve lock.
For the best consistency (tight ES), you always want the hammer spring adjusted to somewhere in the vicinity of 95 - 97% of the peak velocity. So in other words if you want a lower velocity, you'll want to reduce the regulator's setpoint. Then adjust the hammer spring tension to the 95 - 97% mark again.
Upvote 0
Yes your tune is out of whack. Listen to Nervoustrig. Then you’ll get the most out of your gun. Right now you just have a pellet sender. Pretty much a V8 riding around on 7 cylinders.
Upvote 0
Thanks everybody. It's a 350mm barrel with stock Edgun reg. Not sure on the fpe/fps as I don't have a chronograph yet. I'm getting 30 shots from a 250 bar fill currently. I'm going to dial the hammer spring back to factory settings and see and go from there. I may even adjust the reg down to 110 bar. Eventually I'll install a Huma reg just for more shots per fill. I'll say this though, even with the POI shifts the little rifle is brutally accurate, at least out to 33 yards.
Upvote 0
You've gotten some good advice. At 120 bar with the Huma reg and the longer barrel my Classic Leshiy can shoot way over 45 FPE in 25 cal.
Do you want to tune it for just one speed or do you want to have a bit of room to adjust down with just the HST?
One advantage of having the HST below 95% of first velocity peak is that it seems quieter and there is less of a clanky sound at my ear.
It's okay to adjust the HST below 95% but it sounds like you've taken it too far, like others have said.
Do you want to tune it for just one speed or do you want to have a bit of room to adjust down with just the HST?
One advantage of having the HST below 95% of first velocity peak is that it seems quieter and there is less of a clanky sound at my ear.
It's okay to adjust the HST below 95% but it sounds like you've taken it too far, like others have said.
Upvote 0
That’s true, if the velocity fluctuations are not causing too much elevation shift at the distances you’re shooting, backing off the hammer spring will give you a very soft report. What’s happening is the valve is barely getting blipped open so very little air is released, the tradeoff being that it’s not as consistent.
If however you have regulator creep on top of it, the first shot or two are likely to be much slower. Together, that may make it totally unworkable for a pest control rig. That’s why it’s generally preferable to be tuned to the 97% mark where the system is not as sensitive to little variations in pressure.
If however you have regulator creep on top of it, the first shot or two are likely to be much slower. Together, that may make it totally unworkable for a pest control rig. That’s why it’s generally preferable to be tuned to the 97% mark where the system is not as sensitive to little variations in pressure.
Upvote 0
Bold above is a good point. Well actually all of it is but that in particular stood out. When I've turned down my Leshiy well below 95% I've always thought of that as quiet plinking mode and at 97% to be hunting mode. If I do take a pest at the lower power it's often when I've been shooting it anyways so the slow speed of the first few shots isn't a problem. And I never take pests at over 25 yards. I could see where if the lower power mode is the main pest mode and the main purpose of the rifle that it could be a problem.
I'd be curious to hear from the OP if he knows how many clicks he is counter clockwise from zero and if he needs his to shoot at different power levels.
Upvote 0
Update: I returned the hammer spring back to factory settings then, following the vid that edgunwest has posted, reduced the reg to 110 bar. After adjusting the hammer spring four clicks clockwise the rifle is pellet on pellet throughout the shot string. I'm getting 20 good shots with no POi change!
Upvote 0
When you say back to factory settings do you mean all the was clockwise to zero? And then you clicked counter clockwise to four?
For reference, my Huma set to 110 bar required 17 counter clockwise clicks from zero to get to 95% to 97% of first velocity peak. This with the 25/350 barrel.
It was sent to me by previous owner at 7 clicks from zero & was quiet for the power & accurate but spiked coming off the regulator.
Upvote 0
No I just counted back to where it was set when I received the rifle. I am going to order a Huma reg for it as soon as I find one i stock, as well as a .177 barrel.
Upvote 0
If you're curious just keep clicking it clockwise & count the clicks until it bottoms out. Then just count the clicks back to where you were.
I have found the number of clicks to consistently set the speed back to where it was so no concerns about screwing things up.
I have found the number of clicks to consistently set the speed back to where it was so no concerns about screwing things up.
Upvote 0
I doubt anything is wrong with the reg, I believe your tune is out of balance and causing the irregular velocities.
Upvote 0