The High Pitched Ping Noise
Now that the hammer spring noise has been tamed by our damping the HS with a piece of tubing, rubber grommet, or a foam ear plug, there is still another high pitched ping noise.
On my 0.22, it lasts about 1 – 1.5 seconds after firing. It is much fainter and higher pitched than the twang the hammer spring once generated.
The sound reminds me more of a solid piece of metal ringing than a spring.
I had thought adding a air cylinder de-pinger and cushioning the plenum spacer would do the trick, but no.
This faint, high pitched ping wasn’t affected by those maneuvers.
Today, I found one can replicated this ping by dropping the plastic handle of a small screw driver against the breach block from about 1/2 inch.
The noise isn’t as readily elicited if one simply holds the screwdriver while tapping.
The light dropping of the screwdriver handle makes the ping noise happen.
It can also be elicited by at the breach end of the air cylinder, but NOT the front or middle of the cylinder.
The significance of being able to elicit this ping by tapping is that we eliminate confusion with the hammer spring twang AND do it without firing the gun.
That means we can test the air cylinder for this ping when it is removed from the gun.
Knowing this, it is now possible to check if this ping source is in air cylinder or the breach block.
I’m hoping that the next time someone is pulling the air cylinder, they first check for this before separating the two.
That lets you learn the ping.
Then test the cylinder and breach block independent of each other once they have been separated.
That will help identify where this high pitched ping originates and work on squelching this additional ping source.
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That may be it. But in order to do the oring mod does the spacer need to be turned down (made smaller in diameter) and then the oring grooves cut? Or just need the grooves? Also what size oring should be used?
That only some of the Vulcans have a ringing spacer is a clue to the mechanism.
I can only think of two ways this would happen.
1 The machining of the spacer has non-perpendicular ends and on some units this causes the spacer to be clamped only on two points.
I don’t think this is very likely.
2. The degree of damping for the spacer is being altered by the amount of silicone grease used during assembly. More grease between the spacer and air cylinder —> good damping.
Less grease —> incomplete damping –> pings.
I think this is the mechanism that causes only SOME of the Vulcans to ring in this manner.
The 0-ring mod ensures damping no matter the amount of grease.
:8: Thanks Ernest!
Yes, but yours has milling slots and orings on both ends.
Ernest was this mod done to my Vulcan or didn’t it need it?
the reg has no back stop to apply tension and that spacer like the cricket so it loosen up at time. took me day to find that ping, with the oring mods —->fix it every time.
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So did you have to change the diameter of the spacer and then cut the grooves for the rings? Or just cut the grooves? If you changed the diameter, what is it now?
And what size o-rings did you use?
[quote=”guykuo”]Thanks, Ernest. Will have to address that next time in the air tube.
The thing I can’t wrap my head around is HOW that spacer can even be ringing wth a couple hundred pounds of thrust squeezing it between the regulator and firing valve assembly.
Doesn’t the fill pressure in the high pressure side of the cylinder push the regulator towards the breach? Or do the o-rings do an amazing job of holding the regulator in place?
It boggles my mind how that spacer manages to be free enough to ring like it does.
Guy[/quote
yes I know how you feel—I though about that also, but there is a moment in time the firing behavior of the reg when it opens to refill the regulated chamber and close that cause the spacer to ping??, what gets me the most is that not all Vulcan do this, only 4 that I have tuned out of 15 or so—but I do know with this mod it made the long ping disappear.
Thanks, Ernest. Will have to address that next time in the air tube.
The thing I can’t wrap my head around is HOW that spacer can even be ringing wth a couple hundred pounds of thrust squeezing it between the regulator and firing valve assembly.
Doesn’t the fill pressure in the high pressure side of the cylinder push the regulator towards the breach? Or do the o-rings do an amazing job of holding the regulator in place?
It boggles my mind how that spacer manages to be free enough to ring like it does.
Guy
[quote=”guykuo”]It’s not bad, but always chasing that last 5%[/quot
That long ping after the shot is coming from the aluminum spacer between the reg and firing valve.
the reg has no back stop to apply tension and that spacer like the cricket so it loosen up at time. took me day to find that ping, with the oring mods —->fix it every time.
Sometimes it’s no so bad being hard of hearing…… WHAT NOISE?
It’s not bad, but always chasing that last 5%
whatever you do Vulcan will never be quiet if you have your ear on the action.
my sub12fpe gun does not ping, but it still has the blowback, which is the air escaping around the valve pin.
I quietend this gun as much as I could, only the blowback is bugging me now. I think the air serves as airbearing for the valve to close, or just simply the designer missed the o ring from around the valve pin. It is the next thing what is loud. if you ever solve the ping this will become evident as next issue. Sniperqty demonstrates it with the cigarette lighter it gets blown out every shot.
good luck with the ping, yours must be very baaad.
on hw100 there were matched spring sets(hammer spring and valve return spring) different from original to change the ping when some guns were doing it. I never tried those so cant confirm and it is a different gun anyway. and your hammersprings are very strong and compressed a lot so best of luck
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Oring groove only with 1.5 X 18mm oring.
That spacer fits loosely in the AT so no turning required.