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Washers and mistakes...

saxyjt

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Today I decided to address an issue with my Stephanhouser tenor. There were a few hinge tubes that were moving sideways, causing noise and possibly unpredictable pad seals...

I considered a couple of options.

  • One was to drill the pivot screw's supporting hole to let it go further and therefore cure the play. (Please forgive my words that may not be exactly ideal to describe the situation).
  • The other option that I choose was to cut some washers out of some kind of plastic sheet I had. I'm not sure what material it is made of. But at least it appeared to be the right thickness to do the job.

I cut a first piece to try and reduce the play from the rather unusual post that supports many of the lower keys on that horn.

IMG_20200505_144823066~2.jpg


But it wasn't enough. So I went on to cut some small round ones using my punches.

IMG_20200505_144014037.jpg
 

saxyjt

Saxus Circus Maximus
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I cut a first one to try...
IMG_20200505_144325598.jpg


And it seemed to do the job, do I cut a couple more.

IMG_20200505_144637575~2.jpg


And set them into place.

But I had another issue that I tried to fix with adding a piece of felt at the foot of the G# key. To reduce the noise. That reduced the opening of the G# a bit, but that wasn't too bad. The real problem, as I found out later was that it prevented the low B to close property. Bb wasn't that badly affected, so I didn't get it first. But looking closer, it was obvious that the low B pad couldn't close completely.

Lesson's learned for me. Next time I fiddle around the left pinky table, I'll be careful about the side effects...

But the good news is that the washers are doing their job and the action is not as clunky as it was...
 

jbtsax

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There is a saying in saxophone repair that goes, "everything affects everything". It is a bit humorous, but there is also a lot of truth to it---especially when it comes to the LH table as you discovered. Too thick a material on the foot of the G# key can keep the low B from closing completely. The low B key not opening enough can keep the G# key from closing.

Your solution to remove motion in the keys using washers you made is excellent. Stores that sell small hardware for hobbyists often have small brass and nylon washers in various sizes that you may want to watch for.

Techs also have various (expensive) tools to correct key fit. One is a "reamer" that deepens the hole in a post allowing the pivot screw to go further. There are attachment "wheels" for the Ferree's neck expander that allows "stretching" hinge rods to make them longer. For hinge tubes (key barrels) there are different tools to swedge them to make them longer. That said, sometimes the most "elegant" solution is the simplest which is to add a thin washer. :)
 

saxyjt

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I should look for a store like that. It's a dying breed, but there must still be some in Paris.

I tend to keep a lot of small things, in case they come useful one day... My wife doesn't get it. That's why I have my own floor in this house!
 

Stephen Howard

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A few (hopefully helpful) observations...

While all the keys on a horn will wear over a period of time, you tend to find less end-wear on keys that are mounted on point/pivot screws. It does happen, but far less rapidly than on keys mounted on rod/hinge screws.
It's also far less likely to happen on keys that get less use - such as the bell keys.
If I see significant axial (end-to-end) play on bell keys the first thing I'm going to suspect is that the pillars have been knocked out of alignment. This is extremely common; if the horn takes a knock, the resultant shock might not leave a dent...but it can cause the large keys to act like slide hammers - and this will push the pillars apart.
The solution is to reposition the pillars to remove the axial play...and this is typically done by carefully tapping them back into position.

Grinding material off a removable compound bell key pillar is a risky thing to do. If you don't maintain a flat mating surface the pillar will not be held securely against the mount...and if the screw that holds it in place has a limited depth of travel you may not be able to achieve a suitable level of torque. It also knackers the value of the horn.

Fitting washers to barrels is a popular 'bodge' - but it's more commonly used on keys mounted on rod screws.
There's a good reason for this.
Examine the photo below:

shwwimg_pointscrew_wear.jpg


Here's a typical point screw mounted key.
The principal behind its action is that the key barrel is supported on the tapered point of the screw. Ideally there should be full contact between the surface of the point and the corresponding hole in the key barrel. There should be the tiniest amount of clearance between the end of the key barrel and the face of the pillar.
In this diagram you can see that there's clearance between the screw point and the hole in the barrel, and between the end of the barrel and the pillar. It's a worn key, in other words - and it's probably a good representation of the keywork on your tenor.

You can probably see that if you moved the pillar in a little, it would take up the play around the point of the screw and reduce the gap between the pillar and the key barrel. Chances are it would solve the problem.
What you've done is solve half the problem - and the least important half. You've popped a washer on the end of the barrel to take up the gap...but the point screw may well be floating around in free space (for some of the time, at least).

So - your key barrel no longer exhibits axial play....but if you grip the barrel ends and give them a wiggle there's a good chance that they'll move...because your fix has done nothing to reduce radial (side-to-side) play.

However....there may be some reasonably good news.
If your horn has parallel point screws (with a cylindrical head rather than a tapered one) it doesn't matter quite so much where the screw hole is in relation to the screw's point. As long as the screw is able to hold the key in place,, it'll work (though it may not be quite as tight as it was before...and because it's a parallel point it'll never be that tight anyway).

If your keys have no radial play - leave them alone. If they do...remove the keys and very gently tap the pillars towards each other. It's best to tap both ends so that you maintain the correct angle of the screw - and after tapping the removable compound pillar you should always check the tightness of the screw that holds it on the mount.
 

saxyjt

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If your horn has parallel point screws (with a cylindrical head rather than a tapered one) it doesn't matter quite so much where the screw hole is in relation to the screw's point.

Yep:

IMG_20200506_173824513.jpg


I read your article on point screws. ;)

They appear to go rather far into the rod:

IMG_20200506_173953360.jpg


I tried to evaluate how deep the hole really is but it feels soft! o_O

So these are not actual point screws.

PS: Please forgive the poor focus! My phone's not great for Macro photos...
 

Stephen Howard

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Right - so your horn has parallel points...but as they have a tapered tip there's a chance that the barrels are designed to rest on the tip.
The softness is likely down to someone stuffing the hole with leather. It's a common bodge for taking up free play (often seen on cheap horns).
If the keys aren't wobbling (side to side) you may well get away with your washer mod - but I still think you'll be better off tapping the pillars back into place.
 

saxyjt

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If the keys aren't wobbling (side to side) you may well get away with your washer mod - but I still think you'll be better off tapping the pillars back into place.

It's all good now but it was rather bad initially. That's why I decided to act. I considered tapping, but the upper part that holds the 'pseudo point screws' is massive. You can see part of it in the very first picture. It's held by screws to an other massive post that's soldered on the horn. I used a first washer between the two parts but it wasn't enough as it's on one side. The other is not accessible so I didn't pursue that route. Proper copper washers will be great as the plastic ones will 'wash' away quickly I guess...
 

Stephen Howard

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You'd be surprised how easy is it to tap that compound pillar over a tad - and how easy it is for the keys to hammer it over when the horn takes a drop while in its case.

I'd stick with the plastic washers - they're less likely to wear the face of the pillar.
 

saxyjt

Saxus Circus Maximus
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You'd be surprised how easy is it to tap that compound pillar over a tad - and how easy it is for the keys to hammer it over when the horn takes a drop while in its case.

I'd stick with the plastic washers - they're less likely to wear the face of the pillar.

I wouldn't be surprised if it took a hit or more on its way to me. The hard case was only wrapped in tape! And the case had a couple of knocks that suggest it took some serious hits.

Anyways, I managed to bring it back to life, bending a few keys and resetting a few pads. There's more but I would need to go back to archives. ;)

Also, I'm now enjoying a nice 'Shackleton' in the garden, by a lovely evening, so I'm drifting away from washers...

IMG_20200506_203453333.jpg
 
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