Pinning and Tone

[Don Mannino]

Fred,

Thanks for the interesting report - sounds like they are still doing it
the same as in 1994, when I talked to Michael Mohr about it.  He might
be the one you had lunch with - nice guy.

The glue is a rubbery feeling film which is laminated to the cloth.
Then the pre-glued cloth is pulled through and is heated to activate the
glue.

Don

> -----Original Message-----
> From: fssturm@unm.edu [mailto:fssturm@unm.edu] 
> Sent: Saturday, October 25, 2003 1:31 PM
> To: College and University Technicians
> Subject: RE: Pinning and Tone
> 
> 
>    Thanks for your thoughts on this, Don.
>    Going back to the original question, which had to do with 
> current Steinway 
> production and specs, I'd like to offer a little info I got 
> from the factory this week 
> (just got back from a week long seminar). First, how they 
> produce the parts in 
> the factory. The process is as follows:
> 1) Insert bushing cloth in hole - the cloth has glue on one 
> side, but otherwise is 
> unadulterated bushing felt. (Glue is activated by heat, or 
> maybe microwaves or 
> something. The glue is dry when inserted, somewhat like 
> Renner bushing 
> cloth).
> 2) Insert sizing pin, and set up a fairly large number of 
> parts in a fixture.
> 3) Dip the fixture into a teflon solution (just the 
> protruding bushings - the fixture 
> is designed to have just a small portion exposed).
> 4) Allow to dry.
> 5) Remove sizing pin and pin parts together.
>    That's it. I was careful to ask enough questions to 
> determine that there were no 
> further steps (eg, no burnishing). The teflon solution is not 
> emralon/permalon. It 
> has a solvent that is too volatile for shipping (hence not 
> offered to techs). I 
> examined the fixtures, and found dried teflon residue that 
> felt and acted like thin 
> sheet teflon (broke off a bit and fooled around with it. 
> FWIW, it is white when 
> dry).
>    Current doctrine is that Steinway wants 1 to 3 grams 
> friction, and that the teflon 
> most definitely makes a firmer action center than untreated 
> felt. This from a 
> couple people in technical support and C & A. They say they 
> definitely want the 
> lower friction - that it produces better responding action. 
> This is by design.
>    I must say I was impressed by the action portion of the 
> factory. It has been 
> completely re-tooled and reorganized over the past 15 years. 
> We had lunch with 
> the guy who oversaw that for a period of ten years (and is 
> now in over-all quality 
> control). Very impressive person (I'm bad at names, and 
> promptly forgot it). He 
> was quite open about how bad things were when he started. Worn out 
> machines - out of tolerance, slip shod production methods. 
> That was when they 
> were using Renner parts in B's and D's in production. Now all 
> are made in NYC, 
> and production of parts is enough that they are closer to 
> keeping up with orders 
> from the field.
> 
> Regards,
> Fred Sturm
> University of New Mexico
> 
> Quoting Don Mannino <dmannino@kawaius.com>:
> 
> snip
> > - Too little friction causes no problems in tone at all in and of 
> > itself.  It is only because we are using cloth bushings that low 
> > friction results in poor tone because the hammer is not 
> controlled in
> > its motion well enough.  Please understand me here - if you have a
> > very,
> > very firm bushing that will pin with low friction and still have
> > excellent side control, the tone should be fine.  It is the
> > limitation
> > of using a soft bushing material that forces us to pin with
> > sufficient
> > friction to get the control we need.  It is not the friction itself
> > which gives good tone - it is the firmness of the bushing.
> snip
> > Don Mannino
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