Recoil Springs - pic info .....

[R9SCarry]

Thought I'd start a new thread for this.  

Re the discussion on the Recoil Spring I thought I'd take a pic to provide you guys with more info ....




Ref this image ..... I have shown the main spring with cup ... no more need be said on that one.  But there is some doubt as to how the inner 2º spring might be removed.

Well .... subject to a full heads up from Eric, here is the construction.  Note, on the right, the disk which bears on barrel lug - has a threaded spigot .... which appears to engage on a threaded portion of the inner spring guide rod.  The spigot is perhaps 1/4 inch long and I have arrowed the start of that where it meeets the guide rod plain section.

At far left is the end we see in the assemble gun ... and that is the end of the inner guide rod.  The mainspring guide is bored out to accept the inner spring guide rod and itself has of course got a stop collar for the main spring.

I can see that the disk or inner spring retaining disk would have to me unscrewed from the inner spring guide rod - to facilitate removal of same ..... now this is where we need more info.  I'd strongly suspect that the thread is Loctited and ... in order to undo this you would need suiable tools ... and soft vice jaws no doubt.  Probably, you would hold the front end of inner guide rod in soft jaws and ... by dint of some strap wrench perhaps ... unscrew the disk to free off the inner spring .... conjecture right now.

Hopefully we can add this info once aquired.

Hope the pic helps just a bit - hard to show everything with equal clarity.

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NOTE - I have edited this pic to include a warning re the correct orientation of the main spring in the total assembly ..... Texas_Bob posted that he had gotten his other way about - which led to a slide jam.

So .. all those not sure .. check this pic above.

[shelb]

Outstanding job on the graphic!  I would be interested to examine the inner spring of an R9S that has been fired 1000 times opposed to a new one.

[R9SCarry]

I'd agree on that Shelby - useful comparison it'd be.  I am only up to about 300 rounds so - early days!

As I said tho - I guess the Bros Rohrbaugh do not rate this spring with the same importance they do the mainspring.

[MurrayNevada]

Chris:
For the sake of us non mechanical guys can you explain why the two springs do not lose their effectiveness at the same number of rounds?

[R9SCarry]

Mike - IMO it is down to their relative rates.

Guessing here ... but let's say the main spring has a 12# rate ... and the inner one 3#.  The work done by each will be proportional to the rate - and so the larger will ''fatigue'' faster.  It does ''most of the work''.

I see that inner as purely allowing for a ''compound'' effect - it is not working all that hard.  It does tho ''extend'' the function of the main and buffer it somewhat.  In theory, I suspect the inner might need replaced once for every three or four mains ...... that tho is speculation based on little more than ''gut feeling''!

I shall hope soon that we will have some sort of defininitive answer from Eric et al ..... all the better to explain the interactions.

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To add - I have emailed Eric and ... hope in fullness of time he can add some info for me to pass on.

[BillinPittsburgh]

If I understand what I am looking at correctly, both springs are going to take a pounding when the gun is fired.

Depending on the difficulty of disassembly, I wonder if an entire captive assembly is available for purchase?

[R9SCarry]

Bill - yes I certainly agree they both take a pounding but my contention is that the inner will be slower to fatigue as it is bound to be a lower rate.... and whilst an integral part of recoil system .... still 2º.

Captive assembly?  Hmmm ... I think Bill if that were the case, we would be looking at quite some cost ..... considering the component count and quality thereof.  It would mean ....

Inner guide rod, with spring .... plus end disk - and - necessarily too another main spring guide, as that is captive on the assembly.

Maybe - and depending on what Eric has to say about the springs .... this might be something where we could do an ''exchange'' deal .... purchase of new captive assembly but return of original for credit - such that final cost not too great.

[BillinPittsburgh]

This may not be a fair comparison but a Glock captive recoil spring and guide assembly for a model 26 retails for about $15.

I suppose that if the inner spring is tempered so that it is fully compressed at a relatively early point in its stress/strain curve, it wouldn't wear out as quickly, and in such a case it also wouldn't contribute as much to the overall function.  I don't yet own a Rohrbaugh, but I have to guess that it was designed for a fairly significant contribution to overall slide movement control.

I'd be interested to hear what the people at Rohrbaugh have to say on this issue.

[R9SCarry]

Bill ...... info update ...

I had a call from Eric ... mainly because he thought my inner guide rod end disk was not cinched up quite tight .... having seen my pic.

He was right!  Altho it would not undo it did in fact have a half turn available to tighten - thus it was potentially (or could be) a smidgeon too long - I have now got it fully wound in.  He is sending me a replacement ass'y and I'll send back mine.  Probably it was an early days thing where Loctiting was not quite spot on.

Anyways .. Eric asked Karl re this inner spring and its longevity ... well, we are essentially talking here about lifetime useage .. within of course reasonable thru-put.  The AH and Gun Tests R9 - which has had 5,000 or more rounds thru it - is still just fine with that spring.

The thinking would be that - in the event that someone had put thru many, many 1,000's of rounds and there was any issue - it'd be taken care of thru life guaranteee anyways.  So - this spring is not to be considered the same as the main.  Also incidentally - this is not a user takedown deal .... the sub ass'y would have to go back to Rohrbaugh.

If you watch the action when pulling slide back you may notice that the inner spring is taking up just the first (and probably therefore most violent) portion of recoil .... damping if you like the onset of the main spring compression, which then takes all the rest of the work ... thus why I described earlier the ''composite'' nature of the spring's functions.  It's a clever concept I reckon, ''smoothing'' out the whole cycle.

Hope this fills in some gaps.

[BillinPittsburgh]

Thanks for the information, Chris.

[gunner930]

 Just yesterday I "took down" my R9s for the first time and really noticed the layout of the recoil spring and inner spring. I remember thinking it was like coil springs on a car and the inner spring system being like a shock absorber or strut on a car. Again, I can say Rohrbaugh went all out for function and smoothness in the design of this gun.
 "This has been a deep thought by Gunner930"  

[RJ HEDLEY]

" "This has been a deep thought by Gunner930"    

.......Hurts, don't it ??  

[gunner930]

 Yes it does. Too much strain on my weary brain  :-/
  

[mefly2]

My mainspring on an unfired R9S measures 1.5065 OAL after removal from the pistol.  At what length measurement (as opposed to # of rounds fired) should it be replaced.  It occurs to me thay the recoil impulse - hence spring wear - would vary depending upon the mass of the bullet fired / utilized.  Help me convince department nay-sayers ...

[Brenden]

I am sorry for drifting,but not being able to be on the forums as I once was due to some health reasons,I love reading these OLD threads.
And miss some of the posters too!!

Brenden