Poor key morticing

[Conrad Hoffsommer]

At 13:47 9/8/2004 -0500, you wrote:
>Yes, I am aware of how to ease a hole properly, but easing isn't the 
>problem here.  The problem here is that when the key was manufactured they 
>left too much wood in the top part of the balance hole.  If I were to just 
>ease the hole, I would not be correcting the problem.  The key is 
>"teetering" on a pin, so if the bottom of the balance rail hole is resting 
>on the punching the top of the hole will wedge against the pin.  Now the 
>top of "that" hole needs to have clearance when the key is 
>depressed.  When I say top of "that" hole, I don't mean the top of the key 
>button.  I'm talking about one sixteenth to one eighth of an inch above 
>the balance rail hole.  The wood here is about one eighth.  There needs to 
>be clearance at the top of that hole roughly an arch, to clear the 
>pin.  Otherwise the pin will be bending. And, yes Terry they are all 
>tight(pins in the balance rail that is).  Normal Key easing in this area 
>will size the hole, but it will not address the problem at the top of the 
>hole.  My easing tool if used to try this will damage the hole and create 
>more problems.
>
>Mike Bratcher


If it's rubbing on the sides of the mortice:
Try an X-acto knife with one of the blades which look like a miniature 
chisel.  There's one blade which goes into the standard pencil sized handle 
and another which has an s curve offset and fits into the larger universal 
type handle. Sorry I can't see a blade number on them, but any good hobby 
shop, etc. should have a good selection of blades and handles from which to 
choose.

The problem at the _bottom_ of the mortice should be fixable with one of 
the easing tools which go down through the top and
  make an inverted cone out of the hole at the bottom.  You may have to do 
the minichisel bit first to be able to turn the easer (which is flattened 
to fit through the bushings).

For not _too_ serious key problem like that, I've also made an easer out of 
a balance pin mounted in a dowel. Stick it down through the top  and out 
the bottom then work it fore and aft the entire length of the button hole 
to ease the top of the bottom hole.
YMMV





Conrad Hoffsommer, RPT, MPT, CCT, PFP, ACS, CRS.
Decorah, IA

- Certified Calibration Technician for Bio-powered Digitally Activated 
Lever Action Tone Generation Systems.
- Pianotech Flamesuit Purveyor
- American Curmudgeon Society - Apprentice Member and Founder