Kawai let-off (poor jack design?)

[Frank Cahill]

Ron Overs wrote:
> 
> Hi list,
> 
> Frank Cahill wrote
>  I tuned a kawai KG-1 today. It's a gray market piano...two pedals.
> There was very little let-off and in some cases, no let-off.
> 
> Frank,
> 
> this symptom is not unusual for a Kawai KG action.
> The geometry (ie. built in friction) of the KG jack at the let-off button
> is one of the best examples of poor action design in the business.
> 
> Try mounting a wippen on the workshop bench (hold it horizontally by
> clamping the wippen flange onto a support block), substituting the
> let-off button with a plain wooden dowel (also held horizontally).
> Examine the relative motion between the jack tender and the let-off
> button during escapement.
> 
> And how does the KG let-off button cloth survive under real life service?
> It doesn't! As the jack tender gouges a groove in the felt  the let-off
> setting moves toward the string.
> 
> Ron E. Overs
> Sydney, Australia
> 
> Email: ron@overspianos.com.au
> Website: www.overspianos.com.au

-- 


Thanks, Ron.  


Frank Cahill
Associate Member, Piano Technicians Guild
Northern Va