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BoLFeb10-12

Table of Contents


inharmonicity and tension (Stephen Birkett)

----- Original Message -----
From: Stephen Birkett <birketts@wright.aps.uoguelph.ca>
To: <pianotech@ptg.org>
Sent: Saturday, February 10, 2001 8:24 PM
Subject: inharmonicity

Someone asked about inharmonicity and tension:

Inharmonicity is not linked to tension per se. In practical piano terms,
for a plain wire string, assuming the frequency remains the same, the only
design parameters you would change that influence inharmonicity would be
length or diameter...tension follows along accordingly, but tension and
inharmonicty can be independently adjusted.

Inharmonicity is proportional to the ratio of diameter ^2 to the speaking
length^4, i.e. the inharmonicity factor B is
  
  B ~ d^2/L^4

By choosing different combinations of d and L, you can:

1. reduce tension and raise inharmonicity
2. reduce tension and lower inharmonicity
3. increase tension and raise inharmonicity
4. increase tension and lower inharmonicity
5. reduce tension without altering inharmonicity
6. increase tension without altering inharmonicity

You see the futility of trying to relate tension and inharmoncity,
n'est-ce pas?

Stephen

Stephen Birkett Fortepianos
Authentic Reproductions of 18th and 19th Century Pianos
464 Winchester Drive
Waterloo, Ontario
Canada N2T 1K5
tel: 519-885-2228
mailto: birketts@wright.aps.uoguelph.ca

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Toy Pianos (John Musselwhite)

I just watched a story on "ABC World News Tonight" About a huge rising
cult of "toy piano" players. What we're talking about here are those
little things that have the tiny hammers which hit steel bars. There is
actually a concert coming up at Carnage Hall that will feature a toy
piano... no lie!! (I wonder who will get to be the technician). They
interviewed several "serious" toy pianists and also showed the factory
in which these things are built. Any takers?

Rob Goodale, RPT
Las Vegas, NV
..............................................
If I may relate a toy piano story, about ten years ago at the University of
Calgary we were treated to the premiere of a work for *four* toy pianos
composed by Windsor Viney, now at the U. of Waterloo, ON. I imagine the
piano they are using in the Carnegie concert would be similar to the pianos
used in the Calgary concert. I received the four pianos and the original
score as a gift from Mr. Viney so perhaps I could describe them.

These particular toy pianos were made in Japan and have 32 chromatic keys
beginning at C5. Their grand-shaped cases are made from luan plywood and
are finished with white polyester. The legs are hard plastic and screw on.
They stand 18 inches high with the legs on, are 15.5 inches wide and 13.5
inches in length. Included with each one was some simple music and a
plastic "bench". The pianos were a "special order" item and cost about $80
each ten years ago so they were fairly expensive toys.

One of them failed to stand up to "concert use", though it made it
through rehearsals and at least one performance of the work. Two others
are in my possession and one was on display at the last Banff PNW regional.
One of them, along with the original score, has been donated to the Chinook
Keyboard Centre (Calgary's excellent piano museum and home of the Garlick
Collection) in its original box complete with accessories. It is hoped that
someday they may be reunited for another performance of the work or made
available to other composers interested in working with toy pianos.

Glad to see toy pianos hitting the "Big Time"!

                 John
John Musselwhite, RPT - Calgary, Alberta Canada
http://www.musselwhite.com http://canadianpianopage.com/calgary
email: john@musselwhite.com http://www.mp3.com/fatbottom

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Cleaning Balance Rail Pins (John Meulendijks)

----- Original Message -----
From: John Meulendijks <jmjmeulendijks@planet.nl>
To: <pianotech@ptg.org>
Sent: Sunday, February 11, 2001 7:45 AM
Subject: Re: Noisy Yamaha action

To introduce my self:

I am a piano-technician/ certified piano tuner working in the Netherlands,
Tilburg. Member of the VVPN/ Europiano. It seems nice to me to join your
list, reading over some subjects.

A way of cleaning that I use on the bottom part of a balance pin (most of
the times when it is oxidated, or even rusty is draping a piece of rope (I
use cotton (plaited/ braided) dipped in copper cleaning fluid) Of course be
careful not to spill on the wooden balance rail. I drape it round it once and
use the loose ends to go back and forward etc. Get it thoroughly clean
afterwards. To leave no residues. (a new piece of clean cotton rope)
If I would like to readjust the balance whole, I would steam it very
shortly, let it dry by itself (takes time!!!) before I just push in a reamer
(conical) up to 3.6 mm cross section. to make the perfect fit.

John Meulendijks

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Strike Weight determining URLs (David Stanwood)

----- Original Message -----
From: David Stanwood <dstanwood@hotmail.com>
To: <pianotech@ptg.org>
Sent: Sunday, February 11, 2001 7:56 AM
Subject: Re: Hammers and Stanwood

Dear Ed,

Strike Weight is a way for measuring hammer weight after the hammer is hung.
  It's a radius-weight measurement like down weight and up weight except it
is applied to the shank/hammer component.

for a drawing of the set-up for strike weight go to:

http://www.stanwoodpiano.com/swsetup.gif

It may also be measured before hanging by measuring Shank Strike Wt:

http://www.stanwoodpiano.com/ss.jpg

Shank Strike Weight plus Hammer Weight equals Strike Weight

When we refer to strike weights being high-medium-low we refer to the zone
delineators I published in the PTG Journal.

Here is a graph for reference:

http://www.stanwoodpiano.com/sw-zones.jpg

required reading for informed conversation that I've written on the subject
of touch weight components:

"Mastering Friction with the Balance Weight System"
PTG Journal - November 1990

"The New Touchweight Metrology"
PTG Journal - June 1996

"Standard Protocols of the New Touchweight Metrology"
PTG Journal - February 2000

"Looking at Grand Pianos Through the Eyes of The New Touchweight Metrology"
PTG Journal - March 2000

"Component TouchWeight Balancing - Blueprint for the Future"
PTG Journal - April 2000

Also,.... shank strike weights usually average around 1.8 grams so if you
want to translate strike weight to hammer weight just subtract 1.8.

So if you have any questions or discussion about touch weight it's important
for you to supply DATA!!!!

Hope that answers your question and raises some new ones....

David C. Stanwood

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Action Bedding (Kevin Ramsey)

----- Original Message -----
From: Kevin E. Ramsey <ramsey@extremezone.com>
To: <pianotech@ptg.org>
Sent: Monday, February 12, 2001 7:42 AM
Subject: Re: action bedding

    Hi, guys, (and gals). I have a little trick that works in conjunction
with the technique that Terry is using that should help. The "lift and tap"
method works once you get the glides close enough to use it, but what do you
do when they're so far out that you can't hear a tap? What I do is to take
one of my business cards and cut it so that it just sits below the lip of
the key fronts. Then, I put it right in front of the center glide and back
the glide out. If the key frame is bowed up, causing the front rail to knock,
you'll see the key go down towards the card. If that's the case, I usually
will back the glides off until I get no movement at the front of the key.
Then, using the card as a gauge, I will lower the glides back down starting
at the center glide and working out. As soon as the glide makes contact with
the keybed, you will see the front of the key start to lift, stop at that
point and go to the next glide bolt. After you do that, you know you're
close, and you can lift up on the stack as you tap on the glide bolts for
the final adjustment. Just takes a couple of minutes, and you don't have to
take the stack off or anything.
    On the new Baldwins, with the glides on the front of the keybed, I back
those completely off, then I bed the balance rail, then I will use paper to
bed the front rails. I still don't have to remove the stack.! Hope this
helps.

...........................................

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Action Bedding (Roger Jolly)

----- Original Message -----
From: jolly roger <baldyam@sk.sympatico.ca>
To: <pianotech@ptg.org>
Sent: Monday, February 12, 2001 10:06 AM
Subject: Re: action bedding


> On the new Baldwins, with the glides on the front of the keybed, I back
>those completely off, then I bed the balance rail, then I will use paper to
>bed the front rails. I still don't have to remove the stack.! Hope this
>helps.

Hi Kevin,
              The Baldwin front rail is supposed to have .020" clearance at
the rear of the front rail.
This is the thickness of most 6" machinist rules.
The fastest procedure is as follows,
1. back out the BR glides.
2. set the front rail glides for .020" clearance and good bedding.
3. use a Jaras key leveller to adjust the BR glides, so the plunger just
starts to move, then back off a hair.

This amount of clearance is needed to make sure the sharps will not cause
the rear of the FR to 'clack'.

Fine tune all adjustments aurally. A 5min job.

Regards Roger
  

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Bronzing Powder sources color (Mark Potter)

----- Original Message -----
From: <bases-loaded@juno.com>
To: <pianotech@ptg.org>
Sent: Monday, February 12, 2001 5:44 PM
Subject: Re: Bronzing powder color

HI Lance -

About two years ago or so the topic of Steinway bronze powder came up on
this list, and someone stated positively that Steinway gets their powder
from Walter Wurdack, and marks up the price ridiculously. I ordered some
from Wurdack, and it does indeed seem to be identical in color to the
stuff I got from Steinway (I still had some on hand). And the price is
extremely good - 1 full lb. for under $20 (as of 1999). At Steinway, $20
won't even buy you 4 oz.

If you want to try them:

Walter Wurdack
4977 Flyer Ave.
St. Louis, MO 63139
314-351-6600

Mark Potter
bases-loaded@juno.com
  


You can also buy aerosol cans of what's called "Steinway Gold" from Wurdack.
  Though it is the same color as the current Steinway plates, it is
different from the vintage gold characteristic of the older Steinways which
is much yellower.

David Love

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