Sticky Key

[Larry Stout]

Several keys on one of my bone-buttoned English concertinas occasionally (but only occasionally) stick. Looking at the action to see if I could identify the problem I find that they are more likely to stick a bit when they are a bit out of alignment, and sometimes the peg at the end of the button seems to be rubbing on the side of its hole. The buttons are bushed. The springs may be anything from 50 to 150 years old. What should I do to improve the action and reduce the sticking?

 

Larry Stout

[Richard Morse]

If you mean by "stick", that they sometimes are initially hard (or impossible) to depress and are fine otherwise (as opposed to being hessitant/slow to depress all the way down), then most likely it's due to them hanging up on the outside edge of their guide hole. That would also account for them being "out of alignment" (appearing not plumb).

 

A typical reason why this happens is because pads tend to shrink in thickness over the decades (pad materials compress under the spring pressure) which raises the lever at the button end... and the buttons... often sufficiently such that the little peg sticking out from the bottom of the button might clear it's guide hole when playing (the pad compresses a tad more when in action) and can get hung up at the edge of the guide hole. When this happens enough times the edge of the guide holes get worn to a radius which makes the buttons hang up more often - even to the point that the buttons will become out of alignment when NOT in action.

 

The easy (but not nice) fix is to adhere a thin washer over the end of the guide holes of offending buttons effectively getting rid of the radius and extending the hole such that the button pin will be encased. You'll probably have to remove one of the felt donuts from the end of the button shoulder to make it's travel remain similar to the other buttons.

 

If the pads are old and thin - I'd recommend that you replace the pads which will be thicker resulting in ALL the buttons being a bit further in their guide holes when at rest.

 

If some of the problem keys have really rounded off the guide hole entries so that even new pads won't solve the problem, you can donut the few remaining culprits OR do the bad ones up proper by drilling/filling/reaming the entry area to be square again.

 

Springs and bushings aren't the problem here. One problem that MAY happen with any pad replacement is that you may have to level the buttons again (over time someone may have leveled them to account for pad wear - which will now work against you as the new pads are all the same thickness). This is easy with removable hook-style actions (and time consuming). Bending them with your fingers or a pliers (or better with two pairs of small piers) is better but still fraughtful. Best is to use a pair of special wirebenders which are easy to make or inexpensive to buy. Why more people don't use these simple tools beyond me. Please do - even for a few recalcitrant lever arms.

[Greg Jowaisas]

Hi Larry,

 

Dave Elliott's book covers many common problems and gives lots of good advice. If you don't have a copy you might want to pick one up. Knowing the specific make and type of action (loop fulcrum, hook and eye, bent over, riveted) would help, but here are a few trouble shooting tips:

 

If the button is stuck and won't depress:

 

The angle of the arm on the button side of the pivot is too extreme and the bottom of the button does not seat properly in its hole.

 

Three things to look for:

 

Pivot is loose

Pad collapse

Arm alignment

 

Pivot is loose:

The could happen with any action but lower end Lachenals with the loop of wire for a fulcrum are prone to having the pivot pull out and become loose. If the pivot won't push back in and stay put the best acvice I have heard was remove the pivot and to nick the prongs of the loop that go into the wood with wire cutters (Be Gentle!) The idea is to give the prongs some added holding power.

 

Pad collapse:

In old instruments this can be due to pad collapse. The felt compresses and the angle at the other end of the action arm increases. You can replace the old pad with new, thicker pad.

 

Arm alignment:

If the pads seem ok and it is only one giving you trouble, you can bend the action arm. Check the Elliott or Quann book for details of making an arm adjustment tool. You could also do this carefully with two pairs of pliers. Make any adjustments slowly and gradually. Remember that any changes in the arm angle can result in changes in the button's height. You want it to seat properly but not be lower than all the other buttons.

 

If your button is not springing all the way back up look for:

 

Button roughness

Bushing too tight

Arm to button bushing too tight

Spring tension

Pivot is loose

 

Check that the button is smooth and not too tight in the bushed hole. Fine steel wool can help you remove any grime build up on the button and polish it.

 

Bushing too tight

If the button is smooth and the bushing seems a bit tight you can burnish it by taking a metal rod like a darning needle and pressing the felt against the wood.

 

Arm to button bushing too tight

Check the bushing inside the button making sure the action arm is free to slide and align itself. If it is too tight to allow movement the spring can't do its work properly.

 

Spring tension

You can check your spring's tension and gently bend it to increase it. It is always a good idea to have a few extra springs on hand in case the old one breaks.

 

Pivot is loose: See above

 

I hope that gives you some ideas and I'm sure other cnet members will have some more.

 

Greg

 

And by the time I had finished typing Rich Morse had posted his expert advice including some approaches to remedying a worn guide hole! Gotta love this forum!)

Edited September 14, 2006 by Greg Jowaisas

[Larry Stout]

The instrument in question is the baritone I described in the history forum-- I have a button or two on the left side (which has a sort of hook and eye, more or less typical very early Wheatstone, or perhaps Lachenal, action) and a button or two on the right (which has what I'd describe as "wire bent under a staple" action-this has quite a lot of lateral free play, making clear what the advantage of a rivited action is). There is no problem pushing the buttons and getting the reeds to sound. Every once and a while a button (usually the same ones) sticks about half way down on its way back up-- I can dislodge it by tugging a bit or perhaps just keeping playing and it eventually pops back up (both of those behaviors are less violent than it sounds) giving me a two or three beat unintentional drone. The pads were replaced in living memory (1960's perhaps) and I don't think the indstrument has been played a lot since then. The button heights are uniform. I'll order some springs before I start trying to follow the advice here. The loose pivot problem is a possibility since the kind of action on the right is the same as the low end Lachenal. I'll make one of the tools described in David Elliott's book and measure to see if the offending pad has gotten thinner than the others.

[Richard Morse]

There is no problem pushing the buttons and getting the reeds to sound. Every once and a while a button (usually the same ones) sticks about half way down on its way back up

That sounds like those bushings are too tight and/or the buttons are dirty/tarnished enough to have excessive friction.

 

I think I misread your "out of alignment" description to mean that the buttons were slightly angled to be off-plumb. If the levers are shaped/oriented such that a button be out of align from the guide hole and endplate, then yes, you'll have excessive friction on that side. Gently rebending the levers with wirebenders is the thing to do.

 

-- Rich --

[d.elliott]

Larry,

 

For my clarification, the keys that are sticking, are they by any chance fitted to arms that are 'cranked ' that is in some way bent or dog legged when you look at them in plan view (down the axis of the keys)?

 

Dave

[Larry Stout]

Larry,

 

For my clarification, the keys that are sticking, are they by any chance fitted to arms that are 'cranked ' that is in some way bent or dog legged when you look at them in plan view (down the axis of the keys)?

 

Dave

 

The low G on the right and the G# on the left are the ones I've noticed-- both are on fairly straight levers. Some of the other keys do take rather round about routes to the pad, but they aren't the ones sticking.

 

Larry

[d.elliott]

Larry,

 

That is the best news today. Had the problems been on cranked arms, then it would have been action wear. A very unpleasant condition usually only treated by nasty and messy procedures, recomended anesthetic:- 12yr old malt!

 

You have been given lots of good advice, my approach follows similar lines, and usually runs like this:

 

With the cover off, and the pad in its normal position over, and closing, the hole, key not pressed, is the key guide pin reasonably engaged in its' hole, if not sort it

 

Is the bushing board or end plate key bush loose and folded over causing a tightening of the key's hole? if so sort it

 

If I push the key up and down does the pad and arm start to twist along its action, if so then you have action wear, get help from the whisky bottle.

 

If I push the key up and down the the key cross bush seem to grip the arm end does the whole arm moves out of location from its engagement with the pivot staple or frame? if so then the cross key bushing/ arm fit is too tight, sort it

 

Finally, remove the key from the arm then manipulate the arm so that the pad is in its natural place over, and closing, the hole. Slip the End cover into position and locate with a couple of end bolts. Look down the empty key hole centering the eye in line as well as possible with the guide hole. Does the arm perfectly bisect the key hole? if not then it will never work smoothly. Both the key hole and the guide pin will bind. Adjust the arm by gently bending it and repeat until it is sorted.

 

So engagement of the pin; freedom and extent movement of a pivoting arm within the key; action wear; and alignment of action arm to action plate and end cover. Ah yes, make sure that the spring is aligned and sliding smoothly on the arm's under side, not too closely to the pivot. Also check that the spring's coils are not snagging on pivot posts or any other features

 

Dave

[Larry Stout]

Thanks everybody for your advice. Most helpful.