A treble in trouble

[Roger Jolly]

At 11:30 AM 10/28/97 -0500, A440A@aol.com wrote:
>Greetings all,  can we talk about this?  
>Nice intro.
           I agree with most of what Ed and Del have posted, excessive over
pitch I would question, particularly in the bass.
 However I can add 2cents worth that may help. I have a 1" wide 6" long
piece of maple 1/4" thick. Piano at 20cents above pitch after 3rd chipping.
Rub the strings 6or7 times from the underside up to the pressure bars or
aggraf makes a world of difference, I think it helps to set the bend, it
sure drops the pitch.
Next take a hammer shank at 45 degrees and repeat the rub at the bridge pins.
Due to the stiffness of the wire these bends take time to form, common
sense has to be used as to how much deflection pressure that is used.
  I also like to squeeze the string pair with parallel pliers coming off
the plate hitch pin. In general more problems show up with string security,
levelling, and termination than we would care to admit to.
regards
rogerjolly
>Del writes:
>>And to a certain extent strings can be
>>"pre-stretched" a bit by rolling them or pressing them--temporarily
>stretching
>>them well above their normal pitch--as is the
>>practice of some factories and rebuilders. These practices can all >help to
>improve initial tuning stability. 
>
>     I agree, however, these practises can overstretch a lot of strings.
> There is a limit of tension a  wire will accept without deformation, when
>surpassed, you usually have a tonally deficient string, ( at least I do,
>after maybe, a chipping "accident".).  Stretching strings "well above" their
>normal pitch by rolling is asking for excessive stretching.  I think
>factories suffer from some of this, judging by the amount of false strings in
>some domestic instruments. 
>     Is it not worth considering to do the second chipping by pulling all the
>unwound strings, one by one, a semitone sharp, before dropping down to
>perhaps 15 cents sharp?   This  increase, governed by ear, not upper body
>strength,   assures all strings have the slack pulled out of the backstrings,
>hitch pin loops, etc. , and at the same time, assures that you will not
>deform any strings.  If you combine the details of settling all the string
>bends when you have it this sharp,  the piano can be amazingly stable in
>weeks.  
>     The bass strings (IMHO), should have their hitch pin coils settled at
>the hitch pin loops after they are up to pitch.  Do this by lightly grasping,
>(with small pliars, no need for a lot of force here....), the tight windings
>of the hitch pin loop.  Give it a side to side wiggle, while listening to the
>note.  It is not uncommon to hear  year-old bass stringing drop 10 cents with
>just this little stress relief applied to the hitchpin coils.  You can save
>time by relieving them now.  The loop should be flattened against the sides
>of the hitch pin first, though.       Try it, you'll like it.  
>     
>>However, in the end strings are going to stretch under tension at an
>>exponential rate. And it  takes time under
>>tension for the stretch rate to decrease
>>enough so that the piano will hold its pitch reasonably well for more >than
>a couple of months.
>
>     Ok, Del knows more than I do on this, so I am scared to just up an
>disagree here, but I have come to believe that the deformation required of
>the wire at every bend along its length is by far the most important factor
>in determining the stability of the wire's tension.  How much stretch is
>there in the straight portion of the string?
>     After stringing, and chipping once or twice, the process of settling
>seems to be one relieving the bends.  I once found a string that had been
>moved over to make up a "neighbor",  when a string broke.  When I put it back
>on the correct bridge pins, it acted like a new string for six months, even
>though it had been  under tension for years. 
>    For what it's worth/ This morning I tuned a 1 year old Model L.  It has
>been tuned four times in the last year:  the pitch raises required at each of
>these is as follows, 20 cents, 12 cents, 8 cents, 0 cents(today).
>Regards to all, 
>Ed Foote 
>Precision Piano Works
>Nashville, Tn 
>
>hmmm,  (he mutters off to the  shop to look at the new stringing.  plunk,
>plunk, twist, tap, nudge, squint, tune, tune, tap, twist............). 
>
>
Roger Jolly
University of Saskatchewan
Dept. of Music.