"pulley" keys

[Lance Lafargue]

Hey Del,
Maybe I'm confused about the goal and the ideal key/pin relationship.
Shouldn't the very bottom of the hole be _slightly_ larger than the pin?
Essentially what you are doing with a traditional tool is forming a V where
the base of the V is slightly larger than the hole.  I am just coming in
from the bottom and exactly doing that leaving the upper portion alone.  And
_if the upper portion is not effecting the key_, wouldn't that be the most
accurate way?  Thanks,

Lance Lafargue, RPT
Mandeville, LA
New Orleans Chapter, PTG
lancelafargue@bellsouth.net



-----Original Message-----
From: owner-pianotech@ptg.org [mailto:owner-pianotech@ptg.org]On Behalf
Of Delwin D Fandrich
Sent: Tuesday, January 02, 2001 9:40 AM
To: pianotech@ptg.org
Subject: Re: "pulley" keys



----- Original Message -----
From: "Lance Lafargue" <lancelafargue@bellsouth.net>
To: <pianotech@ptg.org>
Cc: <hsrosen@gate.net>
Sent: January 02, 2001 6:56 AM
Subject: RE: "pulley" keys


> Hey Howard, remember me?
> As I do an entire set I can never get them all perfectly consistent.  So,
I
> carry a $40 large/complete set (from Harbor Freight, cheap Korean set) of
> drill bits with me, (lettered, #, etc) and a micrometer.  I mic the key
pin
> and us a drill bit a couple/few thousands on an inch larger than the pin.
I
> chuck the drill bit in a T handle UPSIDE DOWN or CHUCK SIDE OUT/CUTTING
END
> IN THE CHUCK of T handle, and just go through the set from the bottom.
I'm
> careful about entering straight.  I can do a set in just maybe 3-5 minutes
> and know that they are exactly the same for my purpose.  In Louisiana's
> humidity, I do this on almost every action I regulate or do any
substantial
> work on.  I've never had anyone tell me why this is a bad idea....Maybe
now?
> Regards,
>
> Lance Lafargue, RPT
> Mandeville, LA
> New Orleans Chapter, PTG
> lancelafargue@bellsouth.net
> -------------------------------------------------------------

Well, it's not a really great idea, Lance.

Today's tight center rail hole is tomarrow's loose fit. Once the wood is
removed, it is pretty much gone forever. Then you will have 'pulley keys.'

The definition of 'pulley keys,' by the way, is the key with a slightly
oversized center pin hole, allowing it to 'pull' back and forth slightly.
While this is not much of a problem in a vertical unless it gets pretty bad,
in a grand it can get a bit more messy, up to and including an erratic
backcheck line.

With tight key center rail pin holes, you're still best off working from the
top and compressing the wood fibers just slightly with the appropriate tool.
With practice, you'll get consistent enough.

Regards,

Del