Sticking Note(S)

[Roger Hare]

The C#/Eb notes on the accidentals row of my 26-button C/G Lachenal have just started to sound

without the button (R1) being pressed - that is C# is sounding when I push and Eb when I pull.

 

Curses...

 

Before I open the instrument tomorrow, I thought I might seek some advice here, as I have so far

had little experience of fixing concertinas. Two years in, I suppose it's about time I got my feet wet...

 

I've had a look at Dave Elliot's manual and have come away a little 'confused'. I think I could

understand it if only one note was 'stuck', but I can't quite get my head around the idea of both

of them being 'stuck'. Is it likely to be a problem with the reeds themselves, or the mechanics

between the button and the reeds? How do I determine what the problem is, and how do I fix

it - or is it something for a properly competent fettler to have a look at?

 

The only thread I can find here dealing with sticking notes (buttons) seems to deal with pads on

adjacent buttons fouling each other resulting in sticking notes on two adjacent buttons - not

quite the same problem I have?

 

Help!

 

Thank you.

 

Roger

Edited August 30, 2016 by lachenal74693

[Chris Ghent]

Take the end off and inspect the pad on the end of the lever associated with that button. Something will be holding it off the board or it will be loose on the lever. Could also be an issue with the spring.

Edited August 31, 2016 by Chris Ghent

[Roger Hare]

Take the end off and inspect the pad on the end of the lever associated with that button. Something will be holding it off

the board or it will be loose on the lever. Could also be an issue with the spring.

 

Thank you. Taking my courage in both hands, I whipped the end off and found:

 

the disc and pad had parted company

the pivot post had pulled out of its 'seating' on the pad board (do I mean action board?)

as a consequence of the problem with the pivot post, the lever arm waggling about in space, and

the spring had disengaged itself

 

I think that the above might be the order in which things happened.

 

disc and pad re-united with a spot of PVA glue

pivot post re-seated - with a very tiny smear of PVA glue

after drying time, re-assembled

 

Seems to work - for how long we shall see.

 

I wouldn't have given this detailed post-mortem were in not for the fact that the pivot post had become

unfixed. This is not (I think) mentioned in Dave Elliot's manual.

 

Examination of the post with a glass showed very shallow grooving on the base of the post, presumably

to allow it to grip the pad board when in position. I was however able to pull it in and out with hardly any

trouble. I didn't tempt providence by trying any of the other posts! Other than bashing it in really hard with

a small hammer (no, no, please no...). I couldn't think of anything to do except apply a tiny bead of PVA to

the base and push it back home in the hope that the PVA will fix the post more securely. I just hope I haven't

done anything disastrous...

 

Roger

Edited August 31, 2016 by lachenal74693

[Hereward]

I had to do a similar repair to the posts on both ends of my instrument and it looks to me like you handled it in the correct way. I say this because my gluing has worked for months now and was successful and not because I'm any sort of expert with repairs; far from it.

[Theo]

A better method than adding glue is to insert a narrow slip of paper of a sliver of wood into the post hole, then press in the post. It is designed to be a friction fit, so adding a little extra material to tighten the fit is a good long term solution. Don't take it out just to do this but if it comes loose again try this instead of glue.

[Hereward]

That is interesting Theo because my posts don't have holes but fit flat, Mine is a Wheatstone however.

[Theo]

That is interesting Theo because my posts don't have holes but fit flat, Mine is a Wheatstone however.

I can't see what you mean. You mean there is no part of the post that is pressed into the wood?

[Roger Hare]

A better method than adding glue is to insert a narrow slip of paper of a sliver of wood into the post hole, then press in the post. It is designed to be a friction fit, so adding a little extra material to tighten the fit is a good long term solution. Don't take it out just to do this but if it comes loose again try this instead of glue.

 

Thank you, I'll bear that in mind.

 

I wish now that I'd taken a couple of photographs and posted them - I'll certainly do that in the future.

 

It was very interesting for me (as a complete novice 'fettler') to look at the mechanism in detail, in

particular, to see difference between the mechanics of this instrument and those of some of the

top-end instruments which have been pictured in this forum.

 

R.

[Hereward]

As far as I can see the posts are glued to a flat surface.

[Chris Ghent]

If the post has lifted out it may be because the spring tension is very high. Also, pads can be displaced when the button bushing wears out. This lets the button move sideways and if the button moves sideways then the pad is going to move more because it is further from the pivot. The pad can then catch on other pads or the side of the action box.

[JimLucas]

As far as I can see the posts are glued to a flat surface.

 

The cross sections of relatively thin metal posts glued onto a flat wooden surface? Doesn't sound right to me. I would expect any sideways pressure -- even gentle pressure -- on the post to break it loose, no matter what glue was used.

.

Any chance of some photos?

[Dana Johnson]

Spring tension alone is rarely enough to pull posts out, though many do get loose with age and pull out. When the button is released, the momentum of the button and lever can act like a tiny hammer on the post, knocking it upward little by little as the aged wood allows. Some orientations to the grain are more resistant to pull out than others.

Dana