S510 power adjustment screw creeping?

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TenMetrePeter
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Re: S510 power adjustment screw creeping?

Sun Jul 15, 2018 3:19 pm

Roger5 wrote:
Sun Jul 15, 2018 9:58 am
TenMetrePeter wrote:
Sun Jul 15, 2018 7:18 am
Tony, read what Alan said. I am an armchair gunsmith.

Just for my own peace of mind though, to increase regulated pressure do you not wind up the screw and increase the pressure on the spring?
Clockwise decreases reg pressure,anti-clockwise increases. Hope that's a comfy armchair Peter :) Rog
Sod it! Now my brain hurts.
I'm better with a proper drawing.

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tonyc
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Re: S510 power adjustment screw creeping?

Sun Jul 15, 2018 10:23 pm

Archer50 wrote:
Sat Jul 14, 2018 10:48 pm


Personally I always lock the power adjuster screw by putting a 3 x 3 grub screw behind it - I don't use Loctite and I don't rely on the blue nyloc patches on the newer adjustment screws.

Good luck.

Alan
Thanks for this info. I can see a grub screw would stop the adjuster winding out but not necessarily from winding in, which is what I think is happening. I'll give it a try.

Regarding setting the reg I don't have any issues, other than I haven't got round to it. We've digressed from the main topic (my fault) as I was updating Roger5 on the reg creep.

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tonyc
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Re: S510 power adjustment screw creeping?

Sun Jul 15, 2018 10:41 pm

TenMetrePeter wrote:
Sun Jul 15, 2018 3:19 pm
Roger5 wrote:
Sun Jul 15, 2018 9:58 am
TenMetrePeter wrote:
Sun Jul 15, 2018 7:18 am
Tony, read what Alan said. I am an armchair gunsmith.

Just for my own peace of mind though, to increase regulated pressure do you not wind up the screw and increase the pressure on the spring?
Clockwise decreases reg pressure,anti-clockwise increases. Hope that's a comfy armchair Peter :) Rog
Sod it! Now my brain hurts.
I'm better with a proper drawing.

Another digression coming....
I haven't seen the internals of the Altaros reg and wondered how they get around the need for a vent hole. I'm guessing the valve closes by the spring assisting the reg chamber pressure. So reducing the spring pressure results in the reg chamber pressure having to go up to compensate. Contamination of the o-ring presumably increases friction on the reg piston, again requiring additional chamber pressure to overcome it.

Altaros used to advise owners not to disassemble the reg mechanism - hence my comment on the video being new advice.

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Archer50
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Location: Perth

Re: S510 power adjustment screw creeping?

Mon Jul 16, 2018 2:26 pm

If the grub screw is tight, it locks the adjuster against the threads and it won't move in either direction.

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tonyc
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Re: S510 power adjustment screw creeping?

Mon Jul 16, 2018 3:04 pm

Archer50 wrote:
Mon Jul 16, 2018 2:26 pm
!!
If the grub screw is tight, it locks the adjuster against the threads and it won't move in either direction.
I appreciate the intended effect, Alan, but was thinking, as the adjuster is loose and you can't hold it as the grub screw makes contact, it could turn with the grub screw as sometimes happens when using a lock nut unless you can put a spanner on both nuts. I don't doubt that it will work in many cases but, of late, I have a habit of finding the exceptions! :? I'll give it a try
.
Thanks again for your input.

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TenMetrePeter
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Re: S510 power adjustment screw creeping?

Sat Jul 21, 2018 9:06 pm

Archer50 wrote:
Mon Jul 16, 2018 2:26 pm
If the grub screw is tight, it locks the adjuster against the threads and it won't move in either direction.
I tried a m3 x 3 cone point on mine and it turned the adjuster in. I could feel it turning and would not lock. Maybe I'm doing it wrong.

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Archer50
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Re: S510 power adjustment screw creeping?

Sun Jul 22, 2018 5:23 pm

3 x 3 cup point grub screw - never had a problem on any gun, and I've used it on quite a few now. If the power screw is very loose it might reduce your power an fps or two, as the grub screw pushes it very slightly down before it locks, but that's just means the usual Air Arms trial-and-error approach comes into play. For guns that are reasonably well engineered in most other respects, I have never understood why the power adjuster hole is so poorly sized and tapped....

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TenMetrePeter
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Re: S510 power adjustment screw creeping?

Sun Jul 22, 2018 6:47 pm

I'll get some cup points! cheers.

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tonyc
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Re: S510 power adjustment screw creeping?

Mon Jul 23, 2018 5:13 pm

Archer50 wrote:
Sun Jul 22, 2018 5:23 pm
For guns that are reasonably well engineered in most other respects, I have never understood why the power adjuster hole is so poorly sized and tapped....
So it's not just me! Had to send a S400 back under warranty with power creeping down. AA replaced the block saying the hole was over-sized. The gun had to go back again when the pot fell off. I wondered if the loose pot was the original problem, slipping further on and reducing air reserve before it finally fell off and the power jumped the other way.

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TenMetrePeter
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Re: S510 power adjustment screw creeping?

Mon Jul 23, 2018 7:10 pm

Looking at how deep the hole is, if I went for Loctite 222 I am wondering if any would remain on the screw by the time it got to the bottom!

I have found poor engineering in my MPR and a friend's. Mostly tolerances.

Just 2 examples of several...
Badly loctited bolt handle so it spun round. Plenty in the thread but none on the bolt handle recess.
Single m4 grub to hold on the barrel extension (bloop tube). Too small and not enough IMO bearing in mind people often lift the rifle by the muzzle and the sight is on it.
Both are now loctited on!

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