Cannonball key heights

"Gordon: Bending keys is one of the worser things that can happen to a horn, as it will affect not only opening but also the angle between key cup and tonehole."

Are you coming for the perspective of an experienced technician? IF not, exactly what background are you coming from?

What you say is simply not true. A key consists of several parts. A technician adjusting things CHOOSES which part he bends in order to achieve what he wants to achieve, WITHOUT messing up other things. If other things are INEVITABLE messed up, then those are subsequently adjusted too.

BTW, on brand new instruments, there is zero evidence of any adjustments being made by adjusting cork thickness. So guess how they adjust things? And this is backed up by what we see in factory tour videos. (Stack keys do look a bit tacky with corks of different thickness.)

So get used to it, adjustment by bending is a standard and appropriate way to adjust many parts of a sax. Oboes? A different story.. the keys are extremely rigid, and have adjusting screws all over the place.

"As this is a horn deriving from a current production line I was hoping to find some measures for the original key heights or/and for the korks."

When I bought my SA80-SII Selmer tenor, I saw it and two others unpacked, in front of me, fresh from the Selmer factory. Between these instruments, there was variation of key heights (for same stack keys) ranging over about 3 mm. Go figure. Assume NOTHING!! By contrast, Yamaha has published specs of key openings, to 0.1 of a mm.

habschi2 said:

.... Basically you didn´t suggest bending of keys but only warned, that there might have been some bending and therefore
kork thickness might not be representative, right ? Still bending keys is a dangerous territory...

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trahansax has it right.

Yes, there may have been some bending.

No. I acknowledge that bending of metal is a standard and perfectly legitimate way of making many adjustments, including key height. I, and I suspect most technicians, and probably all manufacturers, do it every day. Yes, I mean adjustment for key height( and the associated linkage.) For an experienced technician, it is not dangerous territory. The only reason I might sand away at cork under stack keys is for the lower stack keys, to get the F# linkage arm to sit evenly on the E/F/G stops.

Still bending keys is a dangerous territory, mostly done to correct top and bottom (left right) openings of keys, rarely to correct key opening, as this can damage the angle between key cup and tonehole and the pad will sit on the back or leave the back open afterwards.

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If I want to alter that angle I bend to alter it. If I want to bend a key stop, I bend that. I don't get the two confused! Bending the key stop itself does not bend the key cup arm. They are separate pieces of metal. They can be bent separately. So can other parts of the key.

MusicMedic said:

...I never understood the 1/3 rule that so many people use. I wonder how many folds have actually measured the tone holes and tried for 1/3. This would certainly not work on the most important keys, the stack keys. The tone holes under the stack keys vary too much in diameter... My long drawn-out answer to the key height question is: .....

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And that is why it is only suggested as a very vague start. I don't actually go measuring things myself, nor do I keep this in mind.

I suspect that that 1/3 probably comes from fluid dynamics, where an opening (venting) more than 0.3 of the diameter of the orifice of a poppet valve, makes negligible increase to the flow of the fluid through that valve. i.e. at this opening there is no longer significant turbulent flow.(Part of my formal engineering study. Once again, a general rule.)

Your long drawn-out answer is good stuff, but IMO overkill for many situations, where the design of the sax is such that 'current' venting does not present significant intonation or note-stuffiness issues. IMO, for most modern saxes, plus or minus a mm or even two is really rather insignificant, because of good acoustic design. Most of the time we are not doing a balancing act between intonation and stuffy-sounding notes.

MusicMedic said:

Gordon, I agree with much of what you say here but this time I'm having a hard time. I think your saying that the 1/3 rule is based on an irrelivent science and that you personally never use or even consider this when making adjustments. However, you are suggesting it as a possible 'starting point'. I prefer to let the horn dictate the key heights to me and not the other way around.

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In concept, the poppet valve stuff is highly relevant, in that both concern friction and turbulence in a fluid going through a constricted region; the fact that one is for a liquid and one is for air makes the proportion possibly irrelevant. However I personally have not done the calculations to demonstrate the degree, if any, of irrelevance. Have you? I only mentioned this because it is a POSSIBLE source the figure.

I don't know why you are getting so upset about this. The approx 1/3 has been suggested many times in this forum, and not by me. 1/2 is too large in almost any circumstance. 1/5 is too small in almost every circumstance, so what on earth is wrong with saying that 1/3 is a rough guide? The fact is that it is!

I agree that this method is overkill for many situations.

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I'm glad we agree then

… However, in our shop we only do pro-overhauls and usually for pro players… Even after hours or days of tuning and toning work, there is still room for improvement on every saxophone I work on…."

Well, aren't you lucky! Most technicians have to do several cheap and nasty, or good student horns for every pro horn they work on. And ther is no way they could say in business spending many hours on tuning of these horns which are their bread and butter!!!

"…1 or 2mm's makes a difference. It makes all the difference…."

Sometimes yes, and sometimes no. First, there is no way that the bulk of my customers want double action in the way a stack key links to another key. So openings of stack keys are governed by the openings of each other. If the horn is well designed, then the compromises are such that there are no significanlty dead or out of tune notes.

As a consequence of this, then some keys will have an opening that is fussy, while others will be opening past the point where a mm more or less makes any difference to clarity or tuning.

Yes, of course there are some keys such as low C, where careful compromise is vital, but on most saxes there are also keys where fussiness is simply not an issue. The key opens a comfortable distance, and the clarity and tuning do not change with a mm more or less of opening.

"… A properly set up saxophone is a thing of beauty. That last bit, the tuning and toning part of the job, after the key work is quiet and everything is right, is what makes the work special…"

No dispute with that at all, and I admire attention to detail (both yours and mine!)

However if you spend hours getting a horn perfectly (no such thing actually) in tune for your embouchure, or anay player's embouchure, then the next pedantic player, with slightly different embouchure habits, will more than likely find it out of tune, if we are looking at those last few centimes.

The reality is that for the vast bulk of sax players, paying for all this "hours or days" of pedanticity, which to a degree is tilting at windmills, is out of the question. Yes, there are the exceptions.

And in case you were wondering, It is very, very rare for a sax customer of mine to test play and comment on the tuning of a note here and there, and some of my customers are very fine players.

We have to keep in touch with reality here!

"The quick dismissal of the importance of proper key set-up on a saxophone makes me uneasy."

I think you misunderstand me. Of course I correct glaring errors of venting, and also many that the customer has not even noticed, and any that the customer wants attended to, but we have to keep in touch with reality here… it is crazy to spend "hours or days" correcting something that for the customer is not a problem. I am wary of altering something from what a customer is used to and likes, to something I think is more ideal but which he actually dislikes, or dislikes paying a lot for the time involved.

"…. Similar to when a guy says, "This is the first horn I have changed pads, but I'm sure I got out ALL the leaks." Then I look at a horn on my bench and consider that I will never have all the leaks out."

Sorry, I don't follow you. I would never say that an instrument was perfectly leak free. We are using materials with at least some degree of porosity.