[CAUT] Moving capstans

[David Love]

The knuckle tends to be about 4-5 grams per mm.  The capstan is more
difficult because it depends on the overall keylength.  You can make a
dummy capstan out of a cut-off capstan (us a hacksaw) screwed into a
small block of wood.  Set the block on the key and secure it with double
stick tape.  Measure the BW before and after a measured move.  That will
give you a good idea.  Similarly, I would use a sample shank.  Either
pull the hammer off and reglue it or wrap the end of the new shank with
enough solder to duplicate the strikeweight on the original.  Reweigh
before and after and that will give you an idea.  Be sure you measure
closely the original knuckle position and the new one.  Sometimes they
aren't always put on where they say they are.  

David Love
davidlovepianos@comcast.net 

-----Original Message-----
From: caut-bounces@ptg.org [mailto:caut-bounces@ptg.org] On Behalf Of
Alan McCoy
Sent: Tuesday, October 19, 2004 1:28 PM
To: CAUTlist
Subject: [CAUT] Moving capstans

Hi Folks,

I'd like to pick some of your brains about a problem action. I thought
it
might help the discussion to include my spreadsheet, but the list
administrator thought it better to separate the attachment. If you want
to,
please go to http://www.ptg.org:1406/files/20041019125312.xls for the
worksheet.

Is there some way to calculate how much BW will change when moving
either
the knuckle or the capstan? Or does anyone have enough experience/data
for a
rule of thumb for this calculation?

Comments?

Thanks.


-- Alan McCoy, RPT
Piano Technician

Eastern Washington University
119 Music Bldg
Cheney, WA 99004

(509) 359-4627
amccoy@mail.ewu.edu

 


_______________________________________________
caut list info: https://www.moypiano.com/resources/#archives