[pianotech] Pully keys

[John Delacour]

At 17:59 -0400 23/4/10, Ed Foote wrote:

>Hmm, then the largest diameter is at the bottom, and the  real 
>contact is 3 mm away from the bottom of the key.

>I have found that using the flat-sided,  tapered burnisher from the 
>top allows the smallest diameter to be at the bottom of the hole and 
>a slight widening above it, where the pin would need clearance upon 
>rotation of the key on the pin..  It's my experience that I can get 
>a firmer fit to last a longer time by easing the hole from the 
>inside.

I posted the picture of the Kirkman key thinking you might like to 
comment on it.  Why do you think they went to the extra trouble of 
making them like this?  Things don't always behave as first 
appearances would suggest and I think Kirkman knew what they were 
doing.

JD