Key mortise correction

[Roger Jolly]

At 11:42 AM 8/10/2006, you wrote:
>Jon! The tool Joe Garrett mentions,was first introduced years ago by 
>Yamaha.then APSCO was selling it.It works great.Also,Roger Jolly 
>mentioned it in his posts and classes..  Regards    Isaac

Greetings Isaac,
                              I think it is important to isolate 4 
different problems, and diagnose which one is causing the problem.

1.  The diameter of the balance rail hole. If this is tight, Then the 
Yamaha tool is the best remedy, to ensure the key will slide slowly 
down the BR pin.

2.  The height of the balance rail hole. Once this starts to exceed 
4mm, after touch will be effected and the action will feel 'spongy' 
and sluggish. The cutting style of reaming tool is required to set this height.

3. Badly formed key mortice like Jon encountered, causing the side of 
the mortice to rub against the pin.  Jon took the right approach, 
using a Dremel Tool to obtain the required clearance.

4. Tight key bushing's.  Gently squeeze the bushing to have .002" 
clearance at BR bushings and .005" for FR bushing's.

There is no Magic Bullet, or one stop approach to badly fitting 
keys.  each problem has to trouble shot, and corrected accordingly.

hope this clarifies this for some.

Regards Roger 
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