[pianotech] Easing Balance Holes : Kawai KG-1E

[Ron Nossaman]

On 10/9/2011 7:00 AM, Avery Todd wrote:
> Don,
> What am I misunderstanding here? Shouldn't it be just the opposite,
> ie, freely drop in dry weather and barely slide during humid? If it
> barely slides during dry, it's going to tighten up more during humid and
> be too tight. Right? Straighten me up here if I'm wrong. Hmmm..
> Avery Todd

Unless it's constrained by something, the entire piece of wood changes 
dimension with an MC change, not just the hole. If the key stick gets 1% 
wider with high humidity, the hole gets 1% wider too.

Pinblocks do get tighter with high humidity, because the cross-plys 
constrain the alternate layers and keep the overall expansion from 
happening, so the cross grain expands at the edges, and into the holes.

Ron N