post pitch-raise creep?

[Mark Schecter]

Hi, John.

I have a theory for why it goes sharp when you press. You are adding 
tension to the speaking length in excess of the friction under the capo, 
and therefore the tension between the capo and the tuning pin is 
increased. When you release the pressure on the speaking length, the 
excess tension on the pin side of the capo pulls the string high, and 
the friction under the capo prevents the two segments from completely 
equalizing without further encouragement. And, voila.

My guess as to why the same thing doesn't happen in the agraffe sections 
is that the understring felt adds more friction between the agraffe and 
the tuning pin, and you are not applying enough additional tension to 
the speaking length to overcome it, so the segment does not store 
additional tension, even though some may have tried to sneak through.

Just a guess, though.

-Mark Schecter

John M. Formsma wrote:
> That's interesting, Don. I was fooling around with the method for setting
> the string using a hammer shank. I noticed that there was a certain point at
> which pressing harder on the string made it go sharp, but this was only in
> the top treble sections. That corresponds with your observation about
> pounding hard. (Except that deflecting the string with the shank results in
> downward movement whereas the hammer striking it results in upward movement
> (in grands anyway).)
> 
> Hmmm...not sure just what this means. I need more data. More brains wouldn't
> hurt either. ;-)
> 
> John Formsma
> 
>> -----Original Message-----
>> From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On
>> Behalf Of Don
>> Sent: Tuesday, July 11, 2006 7:41 AM
>> To: Pianotech List
>> Subject: Re: post pitch-raise creep?
>>
>> Hi all,
>>
>> I used to experience "post pitch raise creep" when I was in the "hit it
>> harder than anyone else ever will" pounder camp. I've since joined
>> "pounders annyomous" and now get splendid results tuning at mp to mf.
>>
>> Regards,
>> Don Rose, B.Mus., A.M.U.S., A.MUS., R.P.T.
>> Non calor sed umor est qui nobis incommodat
>>
>> mailto:pianotuna at yahoo.com	http://us.geocities.com/drpt1948/
>>
>> 3004 Grant Rd. REGINA, SK, S4S 5G7
>> 306-539-0716 or 1-888-29t-uner
> 
> 
>