Reverse Torque tuning pins & reverse crown

[David Skolnik]

Hi Dale -
I posted this question to both lists and had a reply from Don Mannino 
on CAUT that explained it quite succinctly, so, without prior 
clearance, heeeeeeeer's DON!

>Reverse Torque Tuning Pins is a marketing term (read, misnomer) for the
>concept of 'cutting' the threads into the tuning pins after plating, as
>opposed to rolling the threads into the pins or plating over the threads
>after cutting.  This cutting process causes the threaded portion of the
>pins to be slightly rough in one direction, but smooth in the other.
>The rough surface increases the pin torque in the pitch lowering
>direction (counter-clockwise), but it is smooth in the pitch raising
>direction (clockwise).  The result is that the effort in turning the
>pins is closer to being the same up or down in pitch, because the
>variation in torque is the opposite of the string tension.
>
>The relative benefit for tuning feel is, of course, a trade-off with
>longevity, as the rough pin does tend to chew at the wood a bit.  Since
>our actual rotation during tuning is small it's not much of an issue,
>but when changing strings it certainly can be.

Thank you Don.  (Who remembers Lawrence Welk?)

Dean - what do you or anyone else know about reverse crown boards, as 
a design parameter, as opposed to a bad hair day.  Perzina is 
apparently using this method in their uprights.  I spoke with one 
gentleman from the West Coast company that is distributing them - 
Piano Empire - but he is not an engineer.  I might be able to find 
out more if I get to MARC.  The one piano of their's that I heard 
sounded good, but I'm having trouble conceptualizing the principles.


regards -
David Skolnik







At 11:18 PM 4/5/2007, you wrote:
>   Hi David
>   What you mean reverse torque pin ? Reverse crown boards I 
> know.  Reverse torque pins I do not. grin.
>   Dale
>List(s) -
>Can anyone tell me about or direct me to information about reversed
>torque tuning pins and the use of reverse crown soundboards?   Thanks
>
>David Skolnik
>Hastings on Hudson, NY
>
>
>
>Dale Erwin--Piano Restorations
>4721 Parker rd
>Modesto, Ca. 95357
>Shop 209-577-8397
>Web site <http://www.erwinspiano.com/>http://www.Erwinspiano.com
>Restoration & Sales of
>Steinway & Sons & other fine pianos.
>" Soundboards by Design"
>
>
>
>
>----------
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