Cricket Wouldn’t Fire
I’d been seeing some erratic velocities lately shooting the Cricket cold (50ish) degrees compared to room temp (70ish). I shot a few through the chrony Tuesday and I had lost 130fps :shock:. I had marked my HSA and knew it hadn’t changed. For the day I ended up just turning the hammer spring up a little to gain some of my lost velocity back. It was too sick and it was too cold to shoot outside anyway so I didn’t worry too much about it. Yesterday, I thought I’d shoot a few to see what the velocities were doing now. The gun temp was 49 degrees. I put 220bar in it, chambered a pellet, pulled the trigger and…………nothing, just the sound of the hammer hitting the valve. :suprisedn: Pulled the magazine out and tried it several more times. My guess is that it’s valve locked due to hp air on the low press side. I’m thinking one of the O-rings has given up the ghost. I checked my weep holes on the air tube and there was nothing leaking. I called Ernest and he thought the regulator was leaking air through to the low side so it wouldn’t be detected coming out any of the weep holes. I’ve got the air tube pulled apart now and in the process of changing all the O-rings in the air tube and the two in the regulator. I ran into a little problem though that I’ll get resolved today. I was pulling the regulator with the end of a aluminum cleaning rod and the damn threads (8/32) broke off in the regulator. Today I’ll get it drilled out and reassembled and see what happens. Thank goodness Ernest has these YouTube tutorial vids out.
jk
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no need to by new reg parts unless they are destroyed or worn beyond reconditioning levels.. all reg parts are serviceable.. heres a basic reg recon vid..
One easy way to polish the black delrin adjusting screw face is to lay a sheet of 1000grit on a piece of glass and rub the face paying attention to work it smooth and flat.
because I had been through the same Odyssey, messing with regs, HST, VST etc, seems that one thing is responsible for those situations, crazy fps, valve locks etc. It is the way that the piston (stem) of the reg burries itself into the flat face of the polymer (delrin maybe) adjusting screw, you all know it, the black one on the high pressure end.
The hollow piston-stem has sharp conical-shaped lip, which is pressed by the low-press air onto the face of the black screw. The sharp lip sometimes make a print on the face, probably on higher adjustments. Given that the lips-on-a-face are a very sensitive mechanical sealing setup, any tiny alteration of the piston alignment eg by extreme temp changes could lead to contact a little eccentric than the previous one, thus air is leaking through it bypassing the reg and possibly lock the valve when pressure is high enough. My solution was to polish the face of the black adjusting screw while inspecting carefully the lip of the piston for any defect.
As for the strange phenomenon of the fps going down when HST goes up, this is because you have almost compress fully the HST spring, not giving it the space to expand sufficiently, thus not getting enough energy out of it to achieve desired hammer hit.
Thanks for the help agior1959, I could see some very,very slight marks on the plastic adjuster that you wouldn’t think would be an issue but as sensitive as these regs are I wouldn’t doubt it a bit. I didn’t inspect the end of the piston stem with a magnifying glass but it looked good. I wonder if a guy could order a new piston and seat?
As far as my question on the HSTA you make perfect sense, same lack of energy as having a short hammer throw on an adjustable hammer striker.
Thanks Again
GRSMKr
agior1959, could you describe your method of polishing the delrin face?
I believe that the medium O-ring (2 mm x 10 mm) and small (2 mm x 4 mm) doesn’t need to leak in order for it to be bad. It just can be warned, harden from age and extreme temperature changes. It could be that it’s ward and because of that getting off center and hanging up inside the regulator body ?
Maybe a different material and or Durometer hardness might be better like Polyurethane O-Rings A90s with a temperature range of -60° to +212° F.
IMO
All three springs need to be balanced to have a descent shot count at reg setting one chooses.
Regulator Belleville washer stack clearance adjustment and hammer spring adjustment or harder or lighter spring. The greater the clearance the harder the hammer needs to hit the value to open it. Value spring adjustment to adjust the efficiency of the shot string, how fast or slow it closes after opening.
~ GKU
Hello to all,
because I had been through the same Odyssey, messing with regs, HST, VST etc, seems that one thing is responsible for those situations, crazy fps, valve locks etc. It is the way that the piston (stem) of the reg burries itself into the flat face of the polymer (delrin maybe) adjusting screw, you all know it, the black one on the high pressure end.
The hollow piston-stem has sharp conical-shaped lip, which is pressed by the low-press air onto the face of the black screw. The sharp lip sometimes make a print on the face, probably on higher adjustments. Given that the lips-on-a-face are a very sensitive mechanical sealing setup, any tiny alteration of the piston alignment eg by extreme temp changes could lead to contact a little eccentric than the previous one, thus air is leaking through it bypassing the reg and possibly lock the valve when pressure is high enough. My solution was to polish the face of the black adjusting screw while inspecting carefully the lip of the piston for any defect.
As for the strange phenomenon of the fps going down when HST goes up, this is because you have almost compress fully the HST spring, not giving it the space to expand sufficiently, thus not getting enough energy out of it to achieve desired hammer hit.
Thanks Larry, it seems like if you have plenty of volume in the plenum which I know we do it would still increase the velocity. Your probably right though on the pour efficiency of over dwelling the valve. I’m sure someone will chime in with additional info. I do have Ernest’s HST adjusting guideline so I may give that a try today and see how it works.
Mike, I’d talked to Ernest about the problem and was planning on sending him the gun for a repair of the current problem and full tune if I didn’t get it figured out. The weather has been so cold here and I’ve been home bound with either the flu or a killer cold that I had nothing else really to do.
JK
Grack, I will try to explain but first I need to say I DON’T CLAIM TO BE AN EXPERT. It is the custom, I’m told, to be shamed into wearing Uncle Hoot’s red leather mini shorts in public if caught dispensing false information. That said, it is possible to to put excess pressure on the Hammer Spring Tensioner (HST). When this occurs the hammer my dwell to long on the popet valve. This condition causes poor air usage and a drop in FPS. The good news is now you know the proper setting on you HST for maximum effect.
That’s all I know about that, I think Wingman or many others may be able to give you a full or much better explanation.
Your Mileage My Vary
LarryW 🙄 🙄
I read the whole post, Now my brain hurts, Could be the whiskey . You guys have done more than I would have done,
I would have just boxed it up and sent it to Earnest,,, Or maybe not..
Mike
Thanks guys, this whole problem didn’t start until the cold temps set in. I think it was borderline not wanting to seal earlier on. But with the metal in the gun reacting to the temps it finally made just enough difference to let the Hp air pass on through. It ended up being about a quarter turn on the regulator adjuster that made the difference. Just a few thousand’s of an inch. Oh well it was a great learning experience.
Larry, could you explain this comment a little more. I’m a slow learner. I don’t doubt it, I just don’t understand it!!!!
“At some point you had you HS preload to tight and over the top of your regulator. When turning CW and decreasing fps, the HST is to much!”
Thanks again,
GRSMKrrrrr
All in all it looks like the medium O-ring and shaft with Belleville washer stack inside of the regulator was some how sticking or getting stuck some how.
Again nice fix and tread Gracklesmacker !
~ GKU
Damn, these regulators are sensitive. I had measured from the face of the regulator to the top of the adjuster when I took it apart the first time. That measurement was 2.124″. Today I left it at 2.109″ That got me back to regulating at 930fps. I’m happy as a lark.
Now someone explain this to me. When I got it back together on my next to the last adjustment it was shooting 850’s. I increase the HS preload 1 full turn and my velocity went down to the 830’s. So then I went CCW 2 full turns and my velocity jumped up to 879-880. :confusedn:
And then after my final regulator adjustment (opening it 1/8 of a turn) my HSA acted as it should. Turning it CW increased the velocity.
jk
Grackesmacker, some good has come from you adventure inside the BUG. Congrats, sounds like you have solved the problem. At some point you had you HS preload to tight and over the top of your regulator. When turning CW and decreasing fps, the HST is to much!
Cheers
LarryW 😎
ATB ~ GKU
That’s great news Gracklesmacker good job !
“Original measurements plus 1/2 turn CW” is a bit much I think but I just came home from my day job and couldn’t reply.
I need to correct myself on my last post above, I may have miss interpreted the video. The only thing is I maybe wrong again but here goes. The only way I can see that the regulator can produce unregulated air. Is that the Delrin seal doesn’t make contact to the regulator steam, it stay open at all fill pressures. There are 4 O-rings on the reg 2 large on the outside, 1 med and 1 small on the inside. If any one of them fails/leaks the second leak hole indicator will dispensed the air. If air doesn’t leak out of the second hole, all the regulator O-rings are holding air. If air does escape from this second hole it could be a cause of any one of the 4 O-rings on the reg. This atmospheric breather hole also leads to the Belleville washer stack inside of the reg and is open to the atmosphere we breath of one bar or 14.5038 psi.
The reason for no fire is that the regulator is not regulating and not closing on the Delrin seal. It’s full effect of the fill is applied to the value and the hammer can’t open it at that full force. Let say fill to 220 bar and the regulator is letting it pass straight through. The full 220 bar is at the valve instead of if the reg was working and closing at 130 bar. That’s almost twice the force pressure on the value and reason for no fire.
~ GKU
Well DUH!
Damn, these regulators are sensitive. I had measured from the face of the regulator to the top of the adjuster when I took it apart the first time. That measurement was 2.124″. Today I left it at 2.109″ That got me back to regulating at 930fps. I’m happy as a lark.
Now someone explain this to me. When I got it back together on my next to the last adjustment it was shooting 850’s. I increase the HS preload 1 full turn and my velocity went down to the 830’s. So then I went CCW 2 full turns and my velocity jumped up to 879-880. :confusedn:
And then after my final regulator adjustment (opening it 1/8 of a turn) my HSA acted as it should. Turning it CW increased the velocity.
jk
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Interesting Wing….