quieting old S-arm linkage WITHOUT replacing it

[Dan Schultz]

Hey, kids!

That hole in the 'S' arm where the pivot screw goes through is also subject to getting elongated from the forces of the pivot screw. I've also been able to get good results by 'peening' that hole (there's that magic word again!) in the 'S' arm a bit and simply resizing it so it is the proper size and ROUND again. Also... some of the later 'S' arms had a Delrin bushing where that pivot screw went through. Those older 'S' arms can be drilled out and the new bushing put in for just a few bucks.

This 'word-of-the-day' thing reminds me of the old Pee Wee Herman schtick where he gave kids all over The World a 'secret word' on Saturday mornings. The kids were then instructed to scream every time they heard the word throughout the weekend.

[Dan Schultz]

O.K. guys I gotta know.
Why on earth would you keep an S Link system that weighs around eight ounces (or more) ?
My ingenious guesses are;
#1 costs less
#2 looks original
#3 looks Pretty
#4 I never play anything fast enough that the slower movement mattered
#5 I bought into that monster weight thing and this is the tuba equivalent

.....

All of the above... especially #4.

[bigtubby]

I think my problem lies in the 15 percent. There is noisy play in the clock spring apparatus before the s link/rotor even moves. I would like to keep my vintage kaiser with s links because it does look pretty. I tried tightening everything but same problem. Any help is appreciated.

Is the cost high on replacing the s links on 4 valves and do you need to also replace the button/paddle?

One of my favorite tubas is a ~120 year old German machine with clock springs/S linkages. I wish to retain the original parts for the same reasons as you: originality and appearance.

The two places I've seen slop in the clockspring mechanisms have been:

1. The bottom link or paddle solder joint broken.
This is repaired by taking the spring out (to avoid softening it with heat), cleaning the old solder joint as much as possible and then hard (silver) soldering it back in place.

2. The "wall" of the spring case has become loose inside the housing.
For this you can carefully peen around the periphery of the disc, making it slightly larger in diameter. Lots of small taps (on the thickness, not diameter) and testing the fit often will make this work well. I use a small dent hammer with a broad polished face for this. It should be a finger press fit.

The rest of the system is as Joe described in OP.

[sailn2ba]

THANKS! I really hope the info here can help me quiet the action on my old Mir 184. It's only a 3 RVer, but it's a super strolling horn and for sentimental reasons, I don't want to cut up the linkages.

[sailn2ba]

. . . and it's not (noticeably) slow (to me).

[sailn2ba]

. . .and 8 oz.!! (Is that additional, or delta?.) My Mir is so light and balanced that, without trying it, I just don't understand what difference that might make.

[tofu]

answer to a very old question:

- Other people enjoy the beautiful "crafty" appearance of original S-arm linkage.

- Another group of people just enjoy keeping some of their possessions "original".

I'd add they are also very durable.

On my '69 185 they are super quiet, super fast and silky smooth. Why in the world would anybody change that???

[Lee Stofer]

To make the S-style linkage valves as fast and dependable as new, sometimes they need more work, and on one occasion I had to disassemble the u-joint assembly at the bottom of the lever and re-build it from square one. Swedging pliers, such as used in woodwind key fitting, tend to do a good job. I have an old pair of Ferree's key-swedging pliers where I re-sized the holes specifically to do key-swedging on rotary linkage. The swedging action fits the brass outer tube to the steel hinge rod inside, with the side-effect of lengthening the tube and removing end-play also. As Joe indicated, this is tedious work and can be easily over-done if not done very carefully.

Counter-sinking the stop arm linkage screw will help with that noise, but on severely worn S-arms, the hole in the end is not round, but egg-shaped, much like on an old clock that needs new bearings. As Dan suggested, I have often peined the steel bearing, shrinking the hole to just-a-little-too-small, then using a smooth tapered key reamer, tediously round it out and open it just enough to where the screw will seat without binding.

This is a lot of work, to restore S-linkage to as good as new, fast and quiet, but it still costs less than amputating the old linkage and building a new linkage that is seldom faster or better than what the original could have been.