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Sticking Key enhanced by Sustain Pedal

Posted By: Duaner

Sticking Key enhanced by Sustain Pedal - 04/16/19 01:29 PM

I have a customer whom I just tuned his piano (smallish apartment size I forgot the name) last week. When I left all was well and he was there and he played a piece and was very pleased. So, I received an email from him stating that he is finding that the A4 is sticking now about every second time he plays that note and that it is enhanced or seems to be worse when the sustain pedal is engaged at the same time. I realize this could be a number of things and I have an idea what I will do of course but still I want to throw this out to the more experienced techs to give me your thoughts on it. I am scheduled to go back tomorrow morning as I'm in the area so I'll need ideas soon. What do you think? tks....dgg
Posted By: That Guy

Re: Sticking Key enhanced by Sustain Pedal - 04/16/19 02:46 PM

Grand or upright?
Posted By: Duaner

Re: Sticking Key enhanced by Sustain Pedal - 04/16/19 03:01 PM

upright.....sorry
Posted By: BDB

Re: Sticking Key enhanced by Sustain Pedal - 04/16/19 03:55 PM

It could be that the head has moved, that the spring is out of place or weak, or that the felt at the bottom of the lever is worn.
Posted By: Gerry Johnston

Re: Sticking Key enhanced by Sustain Pedal - 04/16/19 04:21 PM

Originally Posted by BDB
It could be that the head has moved, that the spring is out of place or weak, or that the felt at the bottom of the lever is worn.

or a tight key bushing
Posted By: Duaner

Re: Sticking Key enhanced by Sustain Pedal - 04/16/19 04:51 PM

Originally Posted by Duaner
,,,,,,and that it is enhanced or seems to be worse when the sustain pedal is engaged at the same time.


....the confusing part to me was how is the damper pedal making the hammer not fall back consistently.....as his email contends? Can you zero in on that as well....tks.
Posted By: BDB

Re: Sticking Key enhanced by Sustain Pedal - 04/16/19 05:52 PM

At some point, you need to figure these things out for yourself. We can give you pointers, but you are in a better position to see what is happening than we are.

The suggestions that I made could prepare you with what you need to bring: you may need a small screwdriver to tighten the head, a long screwdriver to remove the lever, a damper flange, and felt for the lever end.
Posted By: Duaner

Re: Sticking Key enhanced by Sustain Pedal - 04/16/19 08:31 PM

Originally Posted by BDB
At some point, you need to figure these things out for yourself. .


.....just looking for options......sorry for your trouble but thanks for your contributions BDB.....
Posted By: Chris Leslie

Re: Sticking Key enhanced by Sustain Pedal - 04/16/19 09:21 PM

The damper spring causes the damper lever to push back on the whippen spoon............
Posted By: BDB

Re: Sticking Key enhanced by Sustain Pedal - 04/17/19 06:49 AM

I looked at the original question and see that I had thought that the note was sticking by not damping. I was in a hurry to get out of the house and did not read carefully enough. If the something other than the damper sticks more with the damper pedal pressed, that means anything from the wippen and below can be sticking. That can be tight joints, tight key bushings, dirty keys, or something rubbing against something else.

Of course, if it is the damper which is not damping, then my previous advice is good.
Posted By: P W Grey

Re: Sticking Key enhanced by Sustain Pedal - 04/17/19 01:25 PM

A tight key bushing (or two) on a marginally working note CAN produce precisely the symptom you describe, and can easily be missed in the course of tuning, as well an initial test piece after the tuning which doesn't use that key under all circumstances. IOW, he loves your tuning so much that he is now playing more impressively and the problem has "manifested" itself since.

IF that is the case you need to diagnose it and also check for others. Isolate the key movement from the action movement and test each separately. Then track down the exact source if friction. One or the other will show it up.

Pwg
Posted By: kpembrook

Re: Sticking Key enhanced by Sustain Pedal - 04/17/19 01:39 PM

This is common -- and a classic way to diagnose location of the problem of poor repetition in a vertical piano. It would be one of these:
1) tight butt-flange bushings
2) broken/misplaced/weak butt return spring.
Posted By: P W Grey

Re: Sticking Key enhanced by Sustain Pedal - 04/17/19 01:49 PM

Also, if it happens to be console with direct blow action, occaisionally you come across keys that are "front heavy". They worked ok when new (but marginally so). As time goes on and things wear, the slightly front heavy key does not want to return well since sources of friction have now increased somewhat. Add to that possibility a big favor in the whippen cushion...you get the picture.

Successful cure depends on accurate diagnosis. 🤓

Pwg
Posted By: Duaner

Re: Sticking Key enhanced by Sustain Pedal - 04/17/19 05:52 PM

Thanks to all of you....just returned and can report that the entire piano is in need of a good regulation overhaul. Every key is in need of adjustments in their function. I presume that may come soon as the customer will mull over my suggestions.

Anyway, the visit was a success I think. It was A4 sticking and just when I thought I was done A4# decided to stick and babble also. I adjusted the let-off and adjusted the capstan to get a balance then noticed it was still wanting to stick (which looked like the end of the jack when attacking was leaving its proper position (not every time which was odd) and shooting up too far jamming the butt forward. This of course prevented staccato which was the customers original complaint.

So I decided to check out the key bushings and polished the key pins while I had several keys out. Then dry lube A4 & A4# (actually several keys in the area) key bushings. This, I think, saved the day by decreasing friction (and apparently some sticking at these points too) resulting in freedom in the overall function. In the end it came together pretty good and the customer played some tunes and was happy with the result. Got a feeling though that I'll have to return sooner than later with that little piano as the poor overall regulation settles in. It needs a damp chaser also. ......that's my fun for the morning.
Posted By: P W Grey

Re: Sticking Key enhanced by Sustain Pedal - 04/17/19 11:06 PM

Great job Duane!

Pwg
Posted By: Duaner

Re: Sticking Key enhanced by Sustain Pedal - 04/18/19 02:05 AM

Thanks, Peter. Piano regulation work is so essential and of course, in my inexperience it is something else I am going to have to prepare myself for and I will. Never a dull moment with this trade but as always knowing what your options are going into a situation and being prepared for the challenges is so essential.
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