Key Bushing Clearance/Friction, was: Key mortise correction

[Farrell]

Thanks Roger. I thought you might have some sort of fancy method of measuring the clearance of an existing keypin. I'm doing just about the same thing that you do - I use the brass cauls from Pianotek when I ease a set of keys. They also sell a little power regulator - forget what they call it - a reostat maybe - to control the temperature of the iron. You can dial in the perfect temperature - not too hot and not too cool. For lubrication I take a pipe cleaner, fold it over a couple times to increase it's thickness, dip it into the vat of powdered teflon and insert the pipe cleaner into the mortise and rub the teflon into the bushing. I've done this on a few very-high-use (cruise ship piano bar - talk about abuse!) Yamaha C3s with excellent long-lasting results.

Terry Farrell
  ----- Original Message ----- 
  Ric is right' it is touchy, feely kind of thing if using key easing pliers.   How ever I use accurate brass cauls mounted in a 40watt soldering iron. For American made pianos .147" for the balance rail, and .150 for the front rail.
  Japanese pianos. .135" BR and .137" for the front rail.  Available from Pianotech.
  Do not let the iron get too hot.  The tool will lay the nap of the felt down very nicely.
  A thin coat of Protech grease  wiped on to the pins will make the bushing friction come down to the 1-2gm range.

  Regards Roger


    --- Farrell <mfarrel2 at tampabay.rr.com> wrote:

    > Two questions: How do you go about measuring key
    > bushing clearance? And how much key friction does
    > these specs commonly yield?
    > 
    > Terry Farrell
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