Advantages to Uniball linkage/Du Bro Linkage over S-linkage

[tubaguy9]

Besides noise, are there any other advantages to the Uniball or Du Bro linkage over the S linkage?
I'm getting a bunch of custom work done on a horn soon, and labor is free ...I figure why not take advantage of what I can...

Don't worry...it'll be under supervision of someone who is very good at repairs...at a school for it

[The Big Ben]

I just had the rotors rebuilt on my Mira 186. I have S-linkages and they are completely quiet and have no slop at all. Thing is, the S-linkages weren't even touched (except for cleaning and lubing) during the rebuild. This horn is from 1964 and had been used by a school. I have no idea if they had been rebuilt before my ownership. The bearings in the rotors themselves were pretty worn but the S-linkages were fine. Have your valve assembly looked at by a good tech and I bet you could save money by having what is already there put back in order.

To me, the Dubro ends just look....cheap. YMMV.

[Dan Schultz]

Besides noise, are there any other advantages to the Uniball or Du Bro linkage over the S linkage? ....

Nope. I'm not an advocate of replacing 'S' links with more modern linkages unless they are severely damaged or missing altogether.

[imperialbari]

Noise in S-links in some cases may be reduced by using screws with a conical shaft above the threading.

Klaus

[Rick Denney]

S-links work just fine, when they aren't worn out. Yes, it's possible to lay hands on them and make them work again, even if they have some slop. But I've replaced them with Du-Bro links that look acceptable and that will never wear out. I can replace all the links on a tuba myself for about $20, so that's a pretty tempting repair for linkages that need work.

But I don't replace them unless they are worn. Any wear at all, though, will probably cost more in repair bills than it costs to just replace them.

Some of the early ball joints were worse than any S-link, and that includes both plastic and metal ball joints.

Rick "not a fan of that tiny pin on the thin plate at the stop arm end" Denney

[Daniel C. Oberloh]

I just had the rotors rebuilt on my Mira 186. I have S-linkages and they are completely quiet and have no slop at all. Thing is, the S-linkages weren't even touched (except for cleaning and lubing) during the rebuild.

Truth be told BB, we did refit your double hinges and S-link connections to the stop arms. Not a big deal if you understand how its done. Retro-fitting a set of linkage is not always as straight forward as some might think. If you are okay with linkage that flops around a bit, then it is a relatively easy fit. If you want the linkage to be solid in appearance as well as feel, it takes a little more effort. Some configurations require the double-hinge and that complicates matters a tad. All designs require maintenance. The only difference to the owner of the instrument I have seen, is in cost and appearance. Some retrofits can impact the resale value of the horn, so it is a good idea to take that into account as well.

Daniel C. Oberloh
Oberloh Woodwind and Brass Works

[The Big Ben]

I just had the rotors rebuilt on my Mira 186. I have S-linkages and they are completely quiet and have no slop at all. Thing is, the S-linkages weren't even touched (except for cleaning and lubing) during the rebuild.

Truth be told BB, we did refit your double hinges and S-link connections to the stop arms. Not a big deal if you understand how its done

I did not know that! All I know now is that it works like a dream. Quiet, smooth and fast.

Thanks!

[sailn2ba]

Hmm! The slowness of the S-linkages on my old Miraphone 185 3-valve is my only problem with it. Are you telling me that they should be as fast as any? What should be my next step? . . I don't have ready access to a tuba-knowledgeable tech.

[Rick Denney]

Hmm! The slowness of the S-linkages on my old Miraphone 185 3-valve is my only problem with it. Are you telling me that they should be as fast as any? What should be my next step? . . I don't have ready access to a tuba-knowledgeable tech.

A good tech can put most any S-link system to right.

But I can't imagine it would be worth shipping a tuba to make that repair, and if you don't have a good tech in your area, then you have to consider the alternatives.

Here's one of the alternatives:

http://www.rickdenney.com/valve_linkages.htm

Some of the techs may not like it, but you've been warned by them, so you are now empowered to choose for yourself.

Rick "thinking a 3-valve rotary tuba's value is not much in jeopardy" Denney

[sailn2ba]

THANKS. By "right", do you mean that these S-linkages should be as fast as any?

[Rick Denney]

THANKS. By "right", do you mean that these S-linkages should be as fast as any?

When they are right, they work as well as any of the alternatives. When they are wrong, they sound like a percussion section (except that they are operated by a tuba player and therefore on the beat). When wrong, bits have to swedged, filled, drilled, machined, etc. When the plastic ball joints wear, they are adjusted with a small screwdriver.

Nothing's perfect. But I installed those plastic ball joints on my Miraphone 20 years ago, and they still work perfectly and silently. They are not weak, they are as stiff as the S links, they are not all that ugly, and they will not devalue a work-a-day tuba. My Miraphone came with the white plastic Presto linkages, or whatever they were called. Those were dreadful. There is no need for metal on these joints, in my opinion.

But--you might have issues. Sometimes, the ball joint will interfere with the stop arm, and you have to carve a bit of it away or be prepared to bend the arm. Part of installing these is having some mechanical skills so that if you have issues, you can work them out.

Rick "who has installed these on half a dozen tubas" Denney

[tubaguy9]

But I can't imagine it would be worth shipping a tuba to make that repair, and if you don't have a good tech in your area, then you have to consider the alternatives.

I dunno if you read the fine print...

I think I'll stick with my S-linkages the way they are, just have them quieted up when I have the work done on them. I do trust who will be doing the work. If I don't like the way it comes out, I can basically say, "I think this needs some work", and it will be done.

Plus, (since I don't know who else read the fine print)
It's under the supervision of someone that I and many others trust.

[imperialbari]

The old linkages can be noisy at all joints. The most likely reason for slowness of the linkage itself (the rotors themselves may also be slow due to bad alignment of the base plates) is dryness of the double-T-hinges. Thin oil applied to either end of the axles should correct that.

Klaus

[Dan Schultz]

.....The most likely reason for slowness of the linkage itself (the rotors themselves may also be slow due to bad alignment of the base plates) is dryness of the double-T-hinges. ....

True. Also, I've seem many times the 'S' bar itself is bent.... causing the pin thru the stop arm to bind a bit. Most of the time, it's just a lubrication problem that caused the double-T-hinges to bind. Keep 'em oiled, guys. It only takes a couple of seconds every month or so.

[sailn2ba]

Here's the valve section:
http://s690.phothttp://i690.photobucket ... 000400.jpg" target="_blank
I assume that the "double T hinge" is the two pin hinges at the spring end of the linkages. Can those be disassembled for cleaning? . . I don't see any screwdriver slots.
Also, might the springs themselves need cleaning and relubrication?
I think the rotors are OK. I've had them apart, and they spin freely.

[sailn2ba]

Sorry, photo link was messed up. Should be:
http://i690.photobucket.com/albums/vv26 ... 000400.jpg" target="_blank

[imperialbari]

Here's the valve section:
http://s690.phothttp://i690.photobucket ... 000400.jpg" target="_blank" target="_blank
I assume that the "double T hinge" is the two pin hinges at the spring end of the linkages. Can those be disassembled for cleaning? . . I don't see any screwdriver slots.
Also, might the springs themselves need cleaning and relubrication?
I think the rotors are OK. I've had them apart, and they spin freely.

Disassembling the double-T links will destroy them. Supply thin oil from either end of the pins. Eventually the oil will loosen and wash out dirt.

Klaus

[Rick Denney]

I assume that the "double T hinge" is the two pin hinges at the spring end of the linkages. Can those be disassembled for cleaning?

Not usually or easily. The pins are often screwed in place and then soldered, and the outer end peened to retain the hinge. Follow that link I provided, and I think you'll see how those are made.

Rick "thinking these are not usually the source of noise, but often the source of drag" Denney