Twisting an arm?

[PaulDa321]

I have an ICC Vintage with a funky arm and pad issue. It’s on the B/C middle row, RH so probably the first or second most used button when factoring ornamentation. The pad opens at an angle, as if you were taking the lid off of a pot of soup, rather than straight up. This means that when it comes back down, the leather on the bottom drags on the action board slightly. I assume this slows things down and isn’t good for the longevity of the pad. It also has an odd quirk where the tone is flat unless the button is fully pressed.  I suspect that the pad was adhered to the arm at the incorrect angle, but it would be very difficult to remove the pad from the arm.

 

 

I’m wondering if twisting the arm might be an option and if anybody has ever encountered this. I’ve aligned arms laterally and never twisted before. I always stabilize the arm, using two sets of pliers. I did reach out to Sean, but didn’t hear back this time. It’s a liveable quirk, but I think it would play a bit better if the pad raised and lowered without the angle. Let me know what you guys think. 

 

[PaulDa321]

I got a little impatient and gave the arm a little twist and a lateral bend afterwards. Seems like a 50 percent improvement.  I might give it a few days to see how it feels. I do wonder still, if the pad landing at a slight angle will wear it out prematurely 

[alex_holden]

It looks like the slot in the cylindrical post has been cut significantly wider than the flat section of the lever, allowing the lever to rotate as it lifts. This sort of fault is fairly common on vintage instruments with worn action pivots. It causes a 'mushy' feel to the button and eventually a cipher (pad not sealing properly so the note never stops playing). It mostly happens on levers that don't follow a straight line from the button to the pad.

 

I would suggest contacting the manufacturer for advice, though it sounds like you've already tried that. If you have to repair it yourself, I would drill out the rivet, add a thin washer (brass or maybe PTFE) to reduce the side play, and re-rivet it.

[d.elliott]

Alex describes 'cranked arm syndrome' the design 'fault' in Lachenal instruments where you can buy time by moving and reversing the pivot posts. 

 

In this case I support Alex's suggestion but might try adding a thin brass shim first to see what improvement I got first.  

[Clive Thorne]

It may be an optical illusion, but to me, from the video, it looks as if the slot in the pivot has got a bit "splayed" i.e. it's not parralel. If so, could it be closed up by judicial use of mole grips?

[Tiposx]

As an owner of an ICC Vintage concertina I recognise this fault. Two of "my" buttons are set up similarly, but not quite as bad as in the video. I agree with Clive Thorne that the slot is splayed out (as well as being too wide). On mine the hole in the lever is far too big for the rivet (from new) which makes the problem even worse.

 

I don't think that the mole grip squeeze is a good idea though, as the brass post might split, which would be a headache. Also it would not reduce the width of the slot very much at the base.

 

I am considering how to fix mine, and will get busy shortly when I return from holiday. I hope to come up with a working fix with shims or washers, as described by Alex. and also a permanent fix.

 

There isn't much room to work in that area, which makes things difficult.

[PaulDa321]

I do feel like I improved the playing performance a bit with the slight bit of bending work I did on the arm. I have to weigh the risks or headaches of getting in too deep with a fix against any gains I might achieve. I did a couple other bends on two arms since getting it and all have yielded good results, though the others were lateral bends for better alignment of pad to hole. I think with the gap being so large on the brass posts, it makes the initial process of building a correct alignment more difficult to get right.  I do think that if the pad was initially glued onto that arm at a better angle, then it wouldn’t be as exaggerated of an issue.  As it plays currently though, I don’t really notice much difference from that button compared to any other. 
 

 

Edited September 9 by PaulDa321

[Alex West]

Just one observation, looking at the original video.  The "normal" connection of pad to lever arm is via the grommet on the end of the arm and a small disc of leather (samper) on top of the pad, all glued with a small amount of the glue of your choice.  This gives some flexibility for the pad to flex laterally and take up small misalignments to seal fully.

With the amount of glue joining the grommet to the pad and no evidence of a samper, it's practically a solid connection with no chance of flexing.

 

Alex West

[fred v]

On 9/8/2025 at 2:20 AM, d.elliott said:

Alex describes 'cranked arm syndrome' the design 'fault' in Lachenal instruments where you can buy time by moving and reversing the pivot posts. 

 

In this case I support Alex's suggestion but might try adding a thin brass shim first to see what improvement I got first.  

Could you use pliers and pinch the the slot tighter?

[Tiposx]

So I had a closer look at my ICC Vintage action assembly. The lever posts do not have parallel slot sides. The slots are tapered towards the top. So there is little chance that pinching the slots would be an effective fix to the slop.

The rivet is loose along it's axis, with the peen serving only to prevent the rivet falling out.

The hole in the lever arm is a fair bit bigger in diameter than the rivet. There is approximately 30° of twist available just from this.

The slot is .4mm wider than the flattened part of the lever. This is a lot!

It fits like a sausage in an alleyway.

So I have decided to delve a bit deeper and sort it out.

The brass lever post is lightly glued in. I was able to break the bond by twisting a screwdriver in the slot. Just as if the post was a slot-headed screw. After that I used long- nose pliers to twist and pull the post out. There was no damage to the wood, just some burring on the brass post.

I will go further tomorrow. At the moment I guess that a good fix would be to remove the rivet, cut away the brass on one side of the slot, and then rivet the lever properly onto the remaining side of the post.

Photos to follow shortly.

 

[Tiposx]

[Tiposx]

[Tiposx]

I removed the rivet quite easily by filing off the peened end. It appears to be made of copper, which is a surprise to me. I have only seen brass or steel rivets in this application before. The photo shows wear ridges where the titanium (I think) lever arm has rocked and worn into the copper. The rivet is also slightly bent. I will replace this with a 1/16" brass one.

The second photo shows how the slot in the lever post tapers inwards towards the top. This taper/slope is only on one side, so that is the one that I will remove.

The hole in the lever is about the right size for the new rivet, which is good.

More to follow...

[wschruba]

If you have a normal sized (not needle) file, you can test the lever arm--go to the very end (where there is a little extra, hopefully), and mark it all over with sharpie.  If the file skips/removes little, it's titanium.  If it grabs/cuts, it's stainless. 

 

A better material for pivot would be bronze (self-lubricating), but I'm not aware of any suppliers of bronze rivets.  This is also likely a case of, "works well enough".

[Clive Thorne]

Not a comment on the ICC concertina overall, but it strikes me, looking at those photos, that the pivot mechanisms/levers are built to very loose tolerances, i.e. problems waiting to happen.

[David Lay]

38 minutes ago, Clive Thorne said:

Not a comment on the ICC concertina overall, but it strikes me, looking at those photos, that the pivot mechanisms/levers are built to very loose tolerances, i.e. problems waiting to happen.

Sean Garvey recently advised me that he was switching to flat posts (like on his Clare) rather than the slot type for all his line.

Edited September 11 by David Lay

[Tiposx]

I cut the unwanted part of the post away, then cleaned it up on the mill to make a smooth mating surface against the lever. Replaced the rivet with a brass one.

Pushed the post into the locating hole in the action board with a tiny hammer and a tiny dab of Titebond. (the original glue was foaming pu by the look and feel of it).

Everything works properly, the notes on that button are noticeably sweeter and louder than before.

When I have the time I will go back in and see if there are any more sloppy levers.

I have tried to avoid criticising the design and build of the instrument. The pictures and words speak for themselves though.

Edited September 11 by Tiposx
2nd para vague

[PaulDa321]

24 minutes ago, Tiposx said:

I cut the unwanted part of the post away, then cleaned it up on the mill to make a smooth mating surface against the lever. Replaced the rivet with a brass one.

Pushed the pivot into the locating hole with a tiny hammer and a tiny dab of Titebond. (the original glue was foaming pu by the look and feel of it).

Everything works properly, the notes on that button are noticeably sweeter and louder than before.

When I have the time I will go back in and see if there are any more sloppy levers.

I have tried to avoid criticising the design and build of the instrument. The pictures and words speak for themselves though.

Did you put the titebond under the head of the rivet so that it gripped onto the lever arm and turned in conjunction with the lever?