bobbling hammers on Yamaha upright (P-22)

[Piannaman@aol.com]

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Scott, 

I don't think your problem with bobbling hammers is friction related, but it 
sounds like the keys need easing, and the keypins could probably use a  
possible polishing and lube with a dry lube, such as McLube.

Bobbling hammers are frequently caused by letoff being to close.  3/8 inch is 
nowhere near being too close to the string.

The most common cause for bobbling hammers in Yamahas I've found in recent 
times is broken hammer-return spring cords.  These are the loops that hold the 
hammer spring taut to aid hammer return.  Could be several are broken, and if 
that's the case, they are all on the way to disintegration.  There is a fix for 
it that has been posted in recent times.  

Check it out and let us know what's up.



Dave Stahl





In a message dated 12/15/04 9:05:59 PM Pacific Standard Time, Sspeev@aol.com 
writes:


>   Hello everyone. This is my first post, so please excuse any idiomatic 
> slip-ups on my part. 
>  
> Just recently I began learning how to tune, regulate, and repair (by way of 
> apprenticeship).  Before any of this, though, I'd been aware of some bubbling 
> notes on my yamaha p-22.  And so recently i set out to correct the problem, 
> which pervades the mid-range of the keyboard.  Here's what I did: 
>  
> --closed up the hammer-travel distance to 1 3/4" (from 1 7/8").   
> --removed the thinner front rail paper punchings (making the key dip about 
> 7/16") 
> --taken out lost motion
> --regulated aftertouch so that jack just clears hammer butt
>  
> Also--and this was a few weeks back, before dealing with the bobbling 
> hammers--I regulated the let-off so that the jack tripped when the hammer was 
> within 3/8" from string. In retrospect, i wonder if this served to exacerbate the 
> pre-existing problem.  Anyway,  the bobbling is not always readily apparent.  
> Sometimes you can only feel it (and not hear it) during aftertouch.  
> Regardless, it's making the touch feel weird, and pianissimo nearly impossible.  
> 
> One last thing:  many of the keys seem to have a lot of friction to them.  I 
> don't know whether this tightness has to do with the front rail or balance 
> rail bushings.  Either way, it's quite difficult to remove any given key from 
> out of its pins.  
> Does anyone think, then, that this whole thing could be friction-related?
> 



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