Air Venturi Avenge x rattling

[nervoustrig]

shouldnt the cure be to put some kind of thick shim next to/before/after the spring to avoid that exessive play?

In the usual PCP airgun parlance, shimming refers to adding a spacer at one end of the hammer spring. Doing so will indeed get rid of the play, but simultaneously result in the spring being compressed more than before, causing the hammer to hit the valve stem harder, pushing the poppet open further and for longer, causing more air to be released...which in this case is not desirable.

If instead the spacer were between the valve stem and hammer, it would reduce the hammer's travel, which would make the valve open less, using less air...also not desirable.

Bottom line, the approaches that will achieve what you want will require more than just a spacer. Or just enjoy it like it is.

To put this into perspective, I've been involved in airgunning for a little over 10 years and it's a fairly new thing to see broader adoption of the free-flight hammer, which is really a shame considering how simple and effective it is, so from my perspective the idea of taking a new gun and disabling it makes me wince.

[edit] Full disclosure...we don't actually know that more hammer strike isn't desirable for your rifle and its specific regulator setpoint. Or for that matter, that less hammer strike would be optimal. I'm just going by context clues such as what seems to be a lot free play, and that presumably the rifle is currently shooting well given the absence of any complaints of that nature. Ideally you would want to experiment with incrementally increasing hammer strike until you find the gun's peak velocity, and then back off the hammer strike until the velocity falls to somewhere around 97% of that maximum. [/edit]

 

[KatoKevin454]

I wonder if inserting the spring into something like foam or sponge would help, very soft sponge material tube, big enough to keep the spring from rattling, but small enough to not hamper the spring action...... just my suggestion, not sure if it would hold up, but you might give it a try.

 

[Stubbers]

Whole lot of jargon for not really knowing op's situation.

You'd have to dig in, and measure the current free flight. By shimming the hammer to reduce the free flight to within ideal specs (1-1.2mm, 2mm max) you would cause no real harm other than possibly needing to retune, which would be ideal..., very ideal, if you were in the state of excess free flight currently, based on your observations.

Excessive free flight will require excessive hammer preload, which will cause excessive cocking force and add tension onto the sear adding unnecessary trigger weight to your trigger pull, especially if it is as you say, upwards of 2" (unlikely), but even 1/4"-1/2" would be extremely excessive.

Likewise with @nervoustrig 's original suggestion of simply slapping in a longer spring...it would create the same effect he is trying to explain a shim would...so I am quite confused...

Removing all free flight, by shim or spring, will cause wasted air due to the presence of hammer bounce. The purpose of free fight, is to simply reduce the effects of hammer bounce and subsequent re-opening of the valve poppet from such effects.



-Matt

 

[nervoustrig]

Likewise with @nervoustrig 's original suggestion of simply slapping in a longer spring...it would create the same effect he is trying to explain a shim would...so I am quite confused...

Longer, but lighter gauge:

purchase a couple of springs with smaller gauge wire but a bit longer

But yeah we agree the free flight is preferable.

 

[Stubbers]

Longer, but lighter gauge:

But yeah we agree the free flight is preferable.

Longer but lighter is not optimal in controlling hammer bounce, we want shorter stiffer...am I in a twilight zone?

Really, idk why you're attacking the shimming concept, its simpler, and its to shim EXCESS, not ALL free flight, to an optimal range of 1-1.2mm...

Lets not get off topic. OP needs to measure current free flight before anything can move forward...to determine if it is in fact in excess.

-Matt

 

[Stubbers]

Furthermore, OP has exclaimed himself he is green around the edges to pcps. Suggesting to slap in a longer lighter spring will very likely result in a ton of hammer bounce, because the lighter spring can easily absorb more energy from the valve stem pushing the hammer back into said spring.

Nothing should be done until OP finds a way to measure what his free flight currently is. He could simply report back here once that is determined.

Say it is 3/4"...or 19 mm...well then you would want roughly 17-18mm of shim to remove the excess, and you'd be able to retune the rifle to desired velocity with much less hammer tension, or..a slightly lighter spring.

-Matt

 

[Stubbers]

Also, lets not get started on the effects of just slapping in a second reverse wound spring that also eliminates all free flight, good grief, do not do this OP. Adding an additional spring will have detrimental effects without knowing what you're doing, creating more hammer bounce and wasted air then any of the other mentioned approaches.

-Matt

 

[nervoustrig]

Longer but lighter is not optimal in controlling hammer bounce, we want shorter stiffer...am I in a twilight zone?

No, it looks like we are somehow talking past each other. My suggestion of a longer but lighter spring wasn't to control hammer bounce. There already was no hammer bounce, but the OP wanted to eliminate the hammer rattle, so I mentioned one way to do it was to use a longer but lighter spring...with the caveat that it would be compromising efficiency.

 

[Stubbers]

No, it looks like we are somehow talking past each other. My suggestion of a longer but lighter spring wasn't to control hammer bounce. There already was no hammer bounce, but the OP wanted to eliminate the hammer rattle, so I mentioned one way to do it was to use a longer but lighter spring...with the caveat that it would be compromising efficiency.

Longer lighter spring would 100% introduce hammer bounce in this situation...as you made no mention of retaining any free flight by doing so, plus again, lighter springs are more susceptible to this effect, and its not for the faint of heart and green around the edge guy..

-Matt

 

[Stubbers]

When I mentioned shimming some of the excess free flight (if present), I made it clear the optimal free flight that should be present. We done? Or do you wanna trash talk my solution more.

-Matt

 

[nervoustrig]

Longer lighter spring would 100% introduce hammer bounce in this situation

Yes it would, which I have acknowledged multiple times.

its not for the faint of heart and green around the edge guy.

Which is precisely why I didn't want to launch into a detailed tuning guide.

 

[nervoustrig]

When I mentioned shimming some of the excess free flight (if present), I made it clear the optimal free flight that should be present. We done? Or do you wanna trash talk my solution more.

The perceived "trash talk" is a scenario that exists only in your mind.

 

[Stubbers]

Yes it would, which I have acknowledged multiple times.


Which is precisely why I didn't want to launch into a detailed tuning guide.

Introducing twin springs into a pcp not designed for them would require a very extensive tuning guide.

-Matt

 

[Stubbers]

The perceived "trash talk" is a scenario that exists only in your mind.

"If instead the spacer were between the valve stem and hammer, it would reduce the hammer's travel, which would make the valve open less, using less air...also not desirable.

Bottom line, the approaches that will achieve what you want will require more than just a spacer. Or just enjoy it like it is."

Bottom line huh?

-Matt

 

[Stubbers]

Apologies to OP for the abundance of poorly presented information in this thread. I will simply just bow out, I don't have the energy to be combative with others here. Best of luck op!

-Matt

 

[PumaCarl]

To the OP I would say that what you have going on is normal free flight, my AAA Paradigm has it, and it is an uber premium airgun. Don't mess with yours if you like how it's shooting just because you think it shouldn't be making noise. You would basically be wasting your time chasing what isn't a problem, and very likely be giving yourself a real problem.

 

[Maxgasmekl]

Furthermore, OP has exclaimed himself he is green around the edges to pcps. Suggesting to slap in a longer lighter spring will very likely result in a ton of hammer bounce, because the lighter spring can easily absorb more energy from the valve stem pushing the hammer back into said spring.

Nothing should be done until OP finds a way to measure what his free flight currently is. He could simply report back here once that is determined.

Say it is 3/4"...or 19 mm...well then you would want roughly 17-18mm of shim to remove the excess, and you'd be able to retune the rifle to desired velocity with much less hammer tension, or..a slightly lighter spring.

-Matt

Yes I am fairly green to this pcp-game. So - just to get it right. There is nothing wrong with the gun then? Or there is, if the play is too much? If the rifle is made this way on purpose - I will be able to live with it and stop shaking it so much when its not cocked

 

[Dairyboy]

Yes I am fairly green to this pcp-game. So - just to get it right. There is nothing wrong with the gun then? Or there is, if the play is too much? If the rifle are made this way om putpose - I will be able to live with it and stop shaking it so much when its not cocked

It is normal and the gun is fine. It can sound annoying I guess but it is actually a desirable attribute to have a free floating hammer.

 

[cosmic]

How about a thin o ring between the valve and the hammer..

 

[Maxgasmekl]

How about a thin o ring between the valve and the hammer..

Just dont know how to fit it. I think I might just have to live with it If its ment to be its ok