Another Spring Compressor

[Sundog]

Mine is made of wood, so no scuffs or scratches and designed primarily for my FWB124, but it could be adapted pretty easily for any AG.  It has 8-1/2 inches of travel (12” screw shaft), which is a bit long, but the shop manual says to allow “at least 6-7 inches”.  Most of the pieces were already lying around my garage but I think the material cost would be less than $15.  It required a bit of workmanship, but works very nicely.  Waiting for some tar from JM, but I expect it to reassemble just as easily. 






Small block of wood to ptotect the safety slide attached with two-sided tape.





Note the cable tie around the safety and spring.



A bit of tape over the sear pin to keep it from shifting helped much while replacing the plastic the trigger.

[wilsonj1018]

nice compressor man two thumbs up!!! probably one of the better ones ive seen.
Josh

[White Eagle]

I like that design.  Very nice job!

[uncle paulie]

Clean, simple and reasonably inexpensive! WHAT'S NOT TO LIKE?

pv

[Geoff]

looks good but more importantly it works

[bnolsen]

i'm not getting the drive system?  you need a socket and a wrench, the socket to drive and the wrench to hold that nut from turning?

[Frank in Fairfield]

i'm not getting the drive system?  you need a socket and a wrench, the socket to drive and the wrench to hold that nut from turning?

Looks like he has set screw on the nut used to drive the big screw...

I like it too.

[Sundog]

i'm not getting the drive system?  you need a socket and a wrench, the socket to drive and the wrench to hold that nut from turning?

Looks like he has set screw on the nut used to drive the big screw...

I like it too.

There is a nut on the end of the 3/8 inch screw shaft with a 1/8 inch roll pin thru it to keep it from rotating. 


The drill is to move the sliding block a great distance, the 9/16 inch wrench is for better feel once it gets there.  The other nut is partially embedded into a counterbore in the wood so it won't rotate.  The 12mm wrench is for the nut that releases the trigger housing and action.  The screw shaft actually requires minimal torque, I think it could be done just twisting the screw shaft by hand.  I also put a flat washer in the bottom of the hole where the other end of the shaft rides (in the sliding block).  There was some creaking and groaning as the wood compressed for the first time.

Tar arrived today, wow that was FAST!   

 

[lizzie]

That looks excellent- great job!

[amb5500c]

Very nicely done.
Richard

[tomykay12]

Very nice. I am planning one similar with the ability to disassemble without removing the barrel. Probly just a simple split yoke block held down with wingnuts; then one could do either. Might be useful if you are experimenting with spring spacing and don't need to remove the piston every time.  tk

[Sundog]

EPILOG -

So...  I applied the heavy tar to the spring, smells like creosote. 


Loaded the piston, cocking shoe and spring into the tube.  Couldn't find another ty-wrap so I wrapped up the safety and spring with some string.


And squeezed it all together.  Compressor was overkill but worked slicker than snot on a doorknob.



And she's ba-a-a-ck!  Shooting as sweet as ever (maybe better), with a shiney new, light and crispy, stainless steel trigger.



The compressor worked like a champ.  Overkill, maybe, but it was very nice to have the action very secure and the issue not to be a distraction.  I may well never use it again but I feel it was time well spent.

 

[Sundog]

Very nice. I am planning one similar with the ability to disassemble without removing the barrel. Probly just a simple split yoke block held down with wingnuts; then one could do either. Might be useful if you are experimenting with spring spacing and don't need to remove the piston every time.  TK

I considered that type of configuration. In my case, I wanted to tear it all down just to be certain everything was properly lubed, and since it was the first time that I tore the gun down, I was determined to be thorough and cautious.   It would be very easy to modify the end block or switch it out for a different block configuration.

 

[john]

So...don't leave me hangin.  How's that gun shootin' now after the uber-compressor tune-up?

[Sundog]

@John
(Long story)  The Old Girl apparently suffered some abuse at the hands of my teenage son and his friends while I was hard at work making money.  When I finally pulled her out of her case again the stock was broken, she had several scuffs and scrapes, the barrel was bent, the trigger action was lumpy and the safety very sticky.

http://www.gatewaytoairguns.org/GTA/index.php?topic=45588.msg427231#msg427231

After repairing the stock and barrel, I started a cabinet project, so put the 124 up and ordered a JM trigger.  Finished the cabinet project and moved on to make the spring compressor.




When I opened up the action, the safety slide was bent and the sear dented.  Most likely from excessive pressure on the plastic trigger with the safety engaged.

So I pounded the safety flat, stoned and polished the dents out of the sear, tarred and moly-ed the piston and spring, put in the stainless trigger, and adjusted the barrel pivot tension to spec.

In short it probably cycles better than it ever has, and I have been shooting it (off and on) for 35 years.  I only fired a few shots (without sights) but the cocking action was creamy smooth and the trigger light and very crisp even with the screw all the way in.  There was a very noticeable reduction in spring twang and the safety slid easy as before.  So I am very pleased with the outcome.

I intend to chrony it as soon as I find some time and then work on my shooting skills once again.  I have no doubt that it will shoot better than I currently can.

 

[Sundog]

Chrony results using H-N Match Rifle 4.50mm 8.18gr pellets..

855.2
848.6
836.4
841.5
846.3
855.3
839.2

846.1 Mean
7.49 Std Deviation
0.89 Pct Deviation

Oh, wait a moment, I have  a Pellseat...

862.9
856.9
864.8
857.4
857.9
846.4
859.9
854.4
863.5
863.2
867.7
868.0

855.0 Mean
6.13 Std Deviation
0.72 Pct Deviation

I haven't sighted it in or tweaked the trigger yet, but I think I am very happy so far.   

 

[Tater]

That's awesome Parhelion, nicely done.