Why?

[Roger Jolly]

Hi David,
         The test that I use is as follows, hold shank and flange
horizontal, the flange should NOT fall under it's own weight, add the
flange screw and the flange will fall in a smooth but steady manner. Comes
out to four swings.
 So much energy is absorbed in the centre pin/flange bushing, so why are we
so suprised when we change a centre pin and find the tone changes so much.
 Not too long ago I changed a centre pin for what I thought was one weak
note on a Yamaha CF the tone came back with such force that I ended up
changing all the pins in the killer octave. WOW what a diffference. The
tone thickened out and became quite focused. It was an eye opener to
measure the changes in sustain time of the harmonics.
 For about a year I have been removing a few hammers to test for friction
of centre pins prior to voicing, and I feel it has made a big difference to
the quality of jobs that I have been doing. Depending on money I at least
do the critical areas, killer octave and bass/tenor break.
 Start checking I'm sure you will be suprised.
Regards Roger


At 08:56 PM 6/3/99 -0700, you wrote:
>Roger,
>
>Yes, yes, yes...now what kind pinning friction do you go for.  If 
>I'm using a swingtest I like 5 to 6.  Rick Baldassin is really in 
>to tighter pinning claiming the same things you are talking 
>about.  Firmer pinning means a more controlled attack on the 
>string i.e. less wobble.  Obviously if one side is looser than 
>the other you will get wobbly but if both sides are to loose 
>you'll get wobble.
>
>David Ilvedson, RPT
>
>Date sent:      	Thu, 03 Jun 1999 19:08:26
>To:             	pianotech@ptg.org
>From:           	Roger Jolly <baldyam@sk.sympatico.ca>
>Subject:        	Re: Why?
>Send reply to:  	pianotech@ptg.org
>
>> Hi Richard,
>>              I just knew some one would pick up on that statement, I'm
>> smiling.
>> If you have had the opportunity to study slow motion films of a travelling
>> hammer you will notice several things,  1. The shank starts to bend before
>> the hammer starts to move. 2. the hammer does not travel straight to the
>> string but tends to wobble like a drunken sailor in flight. This wobble is
>> far more pronounced on the angled hammers.
>>  I have just completed a test on a Yamaha U1 about 20 years old that was
>> showing the phasing problem at the bass tenor break. Hammers were well
>> traveled and nicely mated to the strings as well as evenly voiced. Both non
>> speaking lengths of the strings were braided to remove this item from the
>> equasion, the strings were seated to the bridges, and the bridge pins were
>> lightly tapped to eliminate false beats.
>>  Problem was still there, and I had duplicated John Woodrow's problem. I
>> then changed the centre pins, Making sure that about same amount of
>> friction was on each side of the flange yoke.  Yureka!!! the problem
>> disappeared.
>>  I think what is happening, is that with a slightly loose pin the flight of
>> the hammer is much more erratic, causing it to strike one string before the
>> other, therefore giving the phasing effect.
>>  I change a lot of centre pins in the killer octave region of grands prior
>> to voicing, and can hear the changes in harmonic structure long before the
>> centre pin starts to give the classic audiable click.  Down at the
>> bass/tenor break there is so much going on sound wise, that I have never
>> previously thought to check.
>>  Another thought for the reason on noticing it more on angled hammers is
>> that the weight not evenly distributed down the centre line of the shank,
>> adding to the wobbly flight pattern.
>>  Hope this sheds some light on your question.
>> regards Roger
>> 
>>  
>> 
>> 
>> 
>> At 11:09 AM 5/9/99 +0200, you wrote:
>> >
>> >
>> >Roger Jolly wrote:
>> >
>> >>
>> >> Similar instability can be noticed at the bass/tenor break, with the
>> >> addition of phasing due to the critical nature of angled hammers.
>> >> I'm sure others will add more reasons, but I would think this is the
>> >> primary cause.
>> >> Regards roger
>> >
>> >I'd like to hear more about this phasing in relation to angled hammers..
>> >
>> >Richard Brekne
>> >Sydneskleiven 1
>> >5010 Bergen, Norway
>> >
>> >E-mail Richard Brekne
>> >Richard Brekne Website
>> >
>> >
>> >>
>> >>
>> >> At 05:41 PM 5/8/99 -0400, you wrote:
>> >> >I am wondering who can provide a definitive answer to the question
of why
>> >> most
>> >> >pianos seem to go out of tune the most at the treble break.  I have
heard
>> >> >several versions of answers, and would like to hear from the best.
I am
>> >> new to
>> >> >the List, and inquiring minds just have to know!    Clark Sprague
>> Greenwich,
>> >> >Ohio
>> >> >
>> >> >
>> >> Roger Jolly
>> >> Balwin Yamaha Piano Centres.
>> >> Saskatoon/Regina.
>> >> Canada.
>> >
>> >Attachment Converted: "c:\eudora\attach\ReWhy.htm"
>> >
>> Roger Jolly
>> Balwin Yamaha Piano Centres.
>> Saskatoon/Regina.
>> Canada.
>> 
>
>
>David Ilvedson, RPT
>Pacifica, CA
>ilvey@jps.net
>
Roger Jolly
Balwin Yamaha Piano Centres.
Saskatoon/Regina.
Canada.