Tuning FX Impact Mk2/M3 - slower first shot - no reg creep - quasi-scientific analysis

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I know this is an old thread but I love to tinker with stuff and this thread was just totally absorbing to me. Im lost when it comes to the charts, but everything here was explained in such a way i had no trouble following along at all...great stuff gentleman, my hat is off to you all. There is defenitly some talented people on here.
 
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FX has now modified the parts so that the o-ring has a flat seating instead of a conical one.
They also press a small bushing behind the o-ring, but this is probably only to keep the o-ring in place during assembly.

94dRFjR.png


A molding of the original part posted earlier in this topic

t6zWv4X.jpeg


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PCPsavage

All about PCP airguns, Tuning, Shooting, Modifying. AvantLink ID: 1483325
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1755009797976.png
 
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Apollo said:
FX has now modified the parts so that the o-ring has a flat seating instead of a conical one.
They also press a small bushing behind the o-ring, but this is probably only to keep the o-ring in place during assembly.

94dRFjR.png


A molding of the original part posted earlier in this topic

t6zWv4X.jpeg


www.youtube.com

PCPsavage

All about PCP airguns, Tuning, Shooting, Modifying. AvantLink ID: 1483325
www.youtube.com www.youtube.com

View attachment 585675
Click to expand...


Is that with a new m4?
Do we know if we can put that part in the older M3?
 
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Agree!

They must have had a lot of these parts left over, because it clearly had to be a solution or at least an improvement on the current part.

Hopefully with the M5, they will go back to the original design with a nut, as you already suggested.

Also, the plastic bushing they press into it makes it very difficult to replace that o-ring.
 
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I'm glad someone brought this up, because it was also part of the reason for the drawing, to show how much material has been removed.

You can see that, in the best case scenario, it is as thick as the cylinder wall at its thinnest point, where one of the outer o-rings is located.
However, in order to withstand the same pressure as the cylinder wall, a flat top or bottom should be at least three times as thick, which is not the case here at all.

They should have only removed the conical portion.
Then the bushing would have made sense too.

yJKCK5x.png
 
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The shaft has an inner diameter of about 8,5 mm, but the flat seat for the o-ring is maybe only 7mm I think since the o-ring is 2,84x2,62.

I hope they’re not all like this, because the part in the photo appears to have been drilled too far, leaving an end that is almost certainly too thin.

A photoshop of how I think it should look.

3qzeVbR.png
 
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