[pianotech] Pully keys

[John Delacour]

I've ended up doing this job using the Schaff tool and the hornbeam 
wrest-plate bushings, and, if I don't count the time spent working 
out the job, it is quick, accurate and efficacious.

The plate bushings are slightly larger than the socket made by the 
tool and have a 2mm pilot bore running about half way down.  To 
reduce the diameter I stuck a dolly wire in a Dremel type tool, runed 
the onto the end and drew them across a sheet of abrasive paper -- a 
few seconds work to get a perfect interference fit.

I set the tool to cut the socket to a depth of a full 3mm, just to 
clear the end of the original balance hole and make visible the 1/4 
inch drilling beyond.  I then brushed the bushing with hot animal 
glue and tapped it home in the socket, pilot hole down because that 
end is chamfered.

Then, with the key upside down in the vice, I cut the protruding 
dowel flush with the line of the key using a Japanese saw and then a 
paring chisel to reveal the pilot hole ready for drilling out with a 
3.6mm drill and burnishing with an awl.

I'll post pictures of the process in the next few days.  It looks so 
far like a solid and durable job.  I have yet to lay the keys, but I 
am not too anxious because, as I said before, the pilot shank on the 
tool aligns itself to the _sides_ of the hole and slight pressure 
towards the back of the key when starting the milling-out prevents 
any influence from the crushed side.  Will Truit's idea is good but 
time-consuming and --I hope I don't have to eat the word! -- 
superfluous.

When I look at the keys I'd give equal blame for the oval holes to 
Steinway/Kluge for bad design, prima donnas for daft playing and 
previous technicians for rough removal and replacement of the keys.

On the old Steinways and most good pianos the balance pins are angled 
backwards to enable the key to be removed by first raising the front 
and then gently lifting off by the chase (button).  Already in 1916 
Wolfenden was complaining that some makers had stopped this practice, 
and he was right to complain.  Clumsy and thoughtless technicians are 
in the great majority and the angling of the balance pins can 
certainly minimize the damage they can do to the keys while making 
things easier also for the minority.

JD