Keybed Warping

[Richard Moody]

> 
> Cliff Lesher wrote:
> > 
> > I am wondering if anyone has seen this before:
> > 
> > The piano:  Chickering console, Serno 185664, Mfd ~1943.  
> > 
> > My inspection revealed the key height to be extremely high.  The keys
> > bottoms were above the keyslip, they were no longer "engaged" by the
> > front-rail pins, and the dip was nearly 3/4". 

This is the puzzler, what is the fall board and or key rail doing? How
could it allow the keys to go this high?  Unless it was shimmed up to
accomodate the  new key height. Take out two keys, grab the balance pins
and try to lift up and down. If there is movement you have a clue.and
proceed. If no movement still proceed.  I think the key frame has to be
looked at.   I would remove all the keys, unscrew the keyframe noting the
postition of all shims, If you don't find the problem doing this I owe you
lunch.  Take it out of the piano and see what it looks like on a flat
surface.  If you find the balance rail is not secure to the cross pieces,
or it screws into the cross pieces but not through to the bed, you can
treat me. You could have a suspended key frame at the balance rail.   
	
Ric Un warping We Will Go
	


 
> > 
" but the rail was shimmed up about 1/8".  Taking the wholesale
> > approach, I removed the shims to see the effect.  After doing so,
> > everything dropped right into place.  

> > Sure enough, the follow-up call came in mid-July, on perhaps the most
> > humid day of the year.  This time the symptoms were just the opposite:
> > zero dip, etc.  My conclusion was that the humidity cycle affected the
> > keybed causing it to crown toward the floor in summer and return to
> > near-flat in winter.