 The Clarinet BBoard
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Author: cuscoclarinet
Date: 2007-01-26 20:04
I'm refurbishing a Vito Bb clarinet for a client and have had no problems until I replaced the spatula keys. The F#/C# and E/B keys go on fine and have good action until I set the F/C key under them. At this point the entire assembly locks up. I've checked them out several times, all the keys are straight and seem to work fine if I put them on one at a time (without the other keys on to hinder thier action) but when I put them on together, they immediately get cludged. I've checked this horn against everything in my shop, but don't have another Vito to compare it to. Am I missing something? Any suggestions would be appreciated.
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Author: C2thew
Date: 2007-01-26 20:17
it could be a bent screw. try using a micro tube sander (long and skinny sanding tool) to clean out the screw hole then try it again. if that doens't work, sand the ends of the key holes. that should do the trick
Our inventions are wont to be pretty toys, which distract our attention from serious things. they are but improved means to an unimproved end, an end which was already but too easy to arrive as railroads lead to Boston to New York
-Walden; Henry Thoreau
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Author: Chris P
Date: 2007-01-26 20:19
Are the screws straight?
Are the pillars straight?
If the threaded inserts in the body are slightly off they will cause the keys to bind up when the screws are tightened.
Is there enough clearance between them all? Make syre the shouldered part of the lever keys isn't pushing against the linkage pieces.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
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Author: Ken Shaw ★2017
Date: 2007-01-26 20:56
Check the thin piece with the crow's foot on the end that runs from the F/C key down between the E/B and F#/C# keys. It can easily bind on one of the lower keys, though I don't think it would hit both of them.
Check the post just below the right finger hole. If it's loose, it could move when you put the F/C key rod through. Also check the lower post for the E/B key and the one for the F#/C# key.
The E/B key and F#/C# keys also "jump" over the left little finger rod for the F/C key. If the rod is bent, you could get binding there.
Try sliding a piece of cigarette paper or cellophane between the narrow gaps and move the keys to see whether each one binds.
Ken Shaw
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Author: cuscoclarinet
Date: 2007-01-26 21:49
Thanks guys, but...
All levers, pillars, screw rods and such are straight and tight. I've also checked to see if any of the linkages are binding, no dice. I've also set the various pivots in deep and out far, thus moving the keys a bit in each direction. That had no effect until I got to a point where the pivots were backed out WAY too far. This is the reason I'm mistified! If it were something that simple I'd be done with it!
I guess I should be a bit more specific, as you are correct Ken, not all the keys are entirely locked. I should have said "cludged" instead.
SO, as specific as I can get without taking video:
The F/C key is almost completely locked, it has about .5mm of action at the pad. Similar action and locking on the F#/C# key. The E/B key has a ridiculous amount of play, as does the E/B lever. The F#/C# lever has considerable play UNTIL the come in contact with the keys, then it has no movement at all. The F/C lever does not come in contact with the F/C key until fully depressed, which means it's doing nothing, as this key is the one that's the most locked up. The Ab/Eb key seems to be fine.
Oh, yes, I have checked to see if in my pre-coffee stupor I didn't set the springs to the wrong sides of the keys or some other really dumb thing. That is also not the issue.
Granted, when I took this horn apart I did think "gee that group of keys and linkages is awfully dense" even more so that usual, but at that time the action was fine on everything. However, I do think the extreme density of this grouping is a design flaw of this particular horn. Sure, it looks cool to have all that metal there, but I'd prefer that the instrument work before it looks cool.
As it's been close to six hours of shop time on these four keys, I'm about ready to throw the towel in with the bathwater. That should give you all some idea of how confusing this whole mess is to me.
SO, I now anxiously await round two of suggestions, and head back to my bench to set the pads on a a really cool horn someone handed to me to do up. It looks like a cross between a Bb clari and a taragato!
Thanks again...
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Author: tictactux ★2017
Date: 2007-01-26 22:24
Can you supply a picture with red circles around the problematic parts? I think I see what you mean but I'd rather see it than just think of seeing it.
--
Ben
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Author: Neil
Date: 2007-01-27 02:29
Looking at my Vito the only thing I can see that would cause the problem you describe is if the projection at the lower end of the LH F/C key which operates the RH F/C key contacts the spring perch on the RH key
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Author: Gordon (NZ)
Date: 2007-01-27 04:50
1. Did you do any swedging in the centre portion of the F#/C# key?
To clarify:
2. Have you actually checked that the mounting arm for the crows foot is not contacting the F#/C# key's "touch piece"?
3. Is it F#/C# locked almost open or almost closed?
4. Is the F/C locked almost open or almost closed?
5. It seems that this binding occurs only for the F#/C# key and F/C keys. Is it true that it does not occur when you mount only one of these keys at a time (and no other keys) "
6. Is it true that this binding DOES occur when you mount ONLY these two keys together (and no other keys)?
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Author: cuscoclarinet
Date: 2007-01-27 06:03
And so it continues...
Gordon, to answer your questions-
1-no I didn't swdge a thing. One nice thing about this instrument is that the keys are made of kryptonite or something. They're almost impossible to bend!
2-I just did check and no, the crow's foot isn't touching anything it shouldn't. As a matter of fact it doesn't touch the E/B key at all unless I actually push down on said (E/B) key.
3-the F#/C# is not entirely locked, but only has about 1mm of action (before it was locked up even worse, and I have no idea what I did to fix this aside from take it apart several dozen times!) between fully closed (as it should be) and open about a mil under pressure.
4-the F/C has the same issue as the F#/C# only in reverse, so sort of as it should be.
5-yes, it is true that the keys have proper action when I mount only one.
6-well, I hadn't tried it until you mentioned it. Yes, if I put the two key on without E/B and Ab/Eb keys on it does bind.
In response to your next question, yes, I pulled of the pads and put thinner ones on, and no, that didn't solve a thing.
At this point I'm about to give up. I've got my computer on my bench and it's watched me pull these keys off so many times that if someone does come up with the right answer it may be able to do the job without me!
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Author: Gordon (NZ)
Date: 2007-01-27 12:15
7. Does the threaded part of the F/C pivot rod go too far through the threaded post and jam up against the part of the F#/C# key that is operated by the F#/C# lever?
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Author: skygardener
Date: 2007-01-27 14:37
It sounds to me like the f#/c# pad is too thick. Did you replace it with the same kind that was on before??
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Author: Gordon (NZ)
Date: 2007-01-27 21:04
"It sounds to me like the f#/c# pad is too thick. Did you replace it with the same kind that was on before??
I assumed cuscoclarinet is an experienced technician.
Is this true, cuscoclarinet? Otherwise a whole range of other possibilites emerge.
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Author: cuscoclarinet
Date: 2007-01-28 00:31
Gordon,
I'm experienced enough. I'm breaking into the field on a pro level after spending years as a player and restoring instruments for myself and others. I'm not so experienced that I can work out anything, but I'm experienced enough that I rarely have to ask for advice.
I've rebuilt my share of horns, merged horns together, done some of my own casting and plating, rebuilt tone holes and tenons. I am not an amatuer except in the strictest sense of the word- amatuer- from the latin meaning "for the love".
It looks like (sadly) there's going to be some bending and grinding involved here. I didn't want it to come ot this, but at this point I'm seeing no other choice.
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Author: Ken Shaw ★2017
Date: 2007-01-28 14:45
Have you tried putting on just the F/C key, leaving the Ab/Eb key off? How about the other way around, with just the Ab/Eb key on?
Bet a nickel it's what Gordon suggested several messages up: the rod that the Ab/Eb and F/C keys turn on is coming through the upper post and binding against the flyover part of the F#/C# key and pushing it up against the same part of the E/B key. Try putting the upper keys on and backing off on the rod.
Ken Shaw
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Author: Gordon (NZ)
Date: 2007-01-28 23:29
If it is indeed what I suggested, tehn just grind off the offensive protruding end of the rod. That'll save the next person goinbg through the same thing.
"It looks like (sadly) there's going to be some bending and grinding involved here. I didn't want it to come ot this, but at this point I'm seeing no other choice."
I do some bending (& sometimes grinding) on almost every clarinet I see, at least for the first time I see it. I assume that my geometry/alignment/adjustment/specs standards are a fair bit higher than those of most manufacturers in most of their models.
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Author: cuscoclarinet
Date: 2007-01-29 13:37
I agree, the bending is comonplace enough. It's the grinding that give me gitters. Not that I can't do it, it's just that it always seems weird to take an instrument that worked fine, take it apart, then have to remove metal to get it to work again.
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Author: tictactux ★2017
Date: 2007-01-29 13:47
Is it possible that one of the posts has twisted out of alignment (the one near the 3rd finger hole has only pivot screws and might have been gone askew a bit)
--
Ben
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Author: Gordon (NZ)
Date: 2007-01-29 14:39
If that were the case, then the jamming would surely occur with only that key on the instrument.
Cuscoclarinet, you mention grinding. What are you planning on grinding? Does this mean you have found the problem.
And have you checked my question 7 of 2007-01-27 12:15
yet? You don't seem to have repoarted back. Nothing wrong with grinding off excess thread on a pivot rod if it causes such strife!
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Author: tictactux ★2017
Date: 2007-01-29 16:53
Gordon mentioned his
> question 7
...You sure all pivot screws are of the same length?
--
Ben
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Author: tictactux ★2017
Date: 2007-01-29 23:41
Gordon (NZ) wrote:
> Meaning???? ......
Sorry, Gordon, I was asking cuscoclarinet.
I "did" a clarinet once that had pivot screws of different length. I wasn't careful enough to sort them properly and ended with too long a pivot screw and a too shallow rod hole - the key would bind. I assume that eons ago a pivot screw got lost and the tech, in order to get the replacement screw working, reamed the rod hole just a bit deeper. The difference wasn't all that obvious to the eye, maybe 1/10 mm, but that was enough.
(edit: I should add that these were pointy pivot screws, not cylindrical ones)
It just boggles my mind that one has to grind something which worked before but wouldn't upon reassembling.
--
Ben
Post Edited (2007-01-29 23:44)
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Author: Gordon (NZ)
Date: 2007-01-30 03:00
I agree, never switch pivot screws or rods or screws, especially the pointed variety.
However this would not explain why the keys on their own do not jam, but they do jam when assembled together.
"It just boggles my mind that one has to grind something which worked before but wouldn't upon reassembling."
If it is what I suspect it might be (my No. 7), then a semi-skilled assembler in the factory would very likely have taken the short cut and simply not screwed the F/C pivot rod all the way home, keeping the keys form binding. Then, when the technician screws it all the way home, as it ought to be, the F#/C# key jams, hence jamming the F/C key.
Nothing too mind boggling about removing the excess length of thread. I often grind (or mill) parts to correct manufacturing faults.
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Author: cuscoclarinet
Date: 2007-01-30 03:20
Bingo on that pivot crew Gordon. I'd imagine you were correct with regards to what a factory tech might do, but this horn is old enough that I imagine it's been tweaked a little in the past.
Thanks heaps for the various suggestions gang.
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Author: Gordon (NZ)
Date: 2007-01-30 10:50
"Bingo on that pivot screw Gordon."
Great! It's fun sleuthing from a distance.
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Author: cuscoclarinet
Date: 2007-01-30 18:26
"Great! It's fun sleuthing from a distance."
And a real pain when it's on your bench!
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