Pin flexing/bending/twisting

[Dave Davis]

Ron N & RicB,

Thanks for the input. I'll look at it from a forensics point of view. I think there is an old pinblock in the shop that didn't get burned in campfires this summer.

Dave Davis


----- Original Message ----
From: Dave Davis dave at davispiano.com
> Has anyone done a study of the negative effects that occur to a tuning 
> pin or the pinblock while tuning? I service a new-ish 7' Bosendorfer for 
> a Boeing engineer, who is a hobbist with older uprights and we've been 
> discussing the rigors the pin endures while being twisted and flexed, 
> and also the affect on the pinblock.
>  
> Dave Davis, RPT
> Renton, WA

<From: Ron Nossaman <rnossaman at cox.net>
Depends on what you mean by a "study". Sans committee, the 
effect on the pin will be inconsequential, and the effect on 
the block will be nearly so. By far, the greatest damage to 
the pinblock (not done at instillation) occurs with humidity 
swings over time.
Ron N

<From: RicB>
I dont think there has been any formal study.  But you dont need to look 
much further then your first set of removed pins to see what can happen. 
Pins bent, grooves often worn flat... then there is this tendancy for 
the holes to develope a kind of glaze-ing resulting in jerky pins.  I've 
heard it speculated on that this can have something to do with tuning 
styles. You could put some psuedo-math/physics on the table and look 
very coarsly at the kinds of stress levels that happen under different 
kinds of twisting forces from the tuning hammer.... but I think it would 
be difficult to conclude anything certain one way or the other.  But it 
might be fun !

Cheers
RicB



     > Has anyone done a study of the negative effects that occur to a
    tuning
     > pin or the pinblock while tuning? I service a new-ish 7'
    Bosendorfer for
     > a Boeing engineer, who is a hobbist with older uprights and we've
    been
     > discussing the rigors the pin endures while being twisted and
    flexed,
     > and also the affect on the pinblock.
     >  
     > Dave Davis, RPT
     > Renton, WA
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