[CAUT] Backcheck replacement revisited (was: balancier/wippens report)

[David Skolnik]

Wim -
In theory you could make a case for the wire length effect, as well 
as the difference in spring effect between a straight wire inserted 
on an angle and a wire inserted perpendicular and then bent.  But 
since we're talking about a process which is affected by everything 
we've been discussing, and in fine increments at that, you'd need to 
be able to quantify the difference.  I don't know that you can easily 
test your theory, as you would have to find a way of lengthening the 
wire without raising the check to isolate the effect you 
describe.  You could accomplish that by removing the requisite amount 
of would from the top of the backcheck block on top of the key, but 
then, of course you have to make sure the wire is still adequately 
supported.  Keep in mind that, whatever the length of the knurling, 
or splines, the height of the installed back check is correct 
relative to the hammertails.  Also, length aside, the newer Steinway 
wires are MUCH stiffer than the original ones.  I don't know what the 
Tokiwa wires are like, though I suspect that they, too, are stiffer 
than the originals.

You should consider the rest of what I've written.  Remember, your 
solution also seemed to require that you rough the tails and weaken 
the rep springs to a degree that, as described  "adjusted some 
springs to where the hammer was just barely rising", seems inadequate to me.

But don't rush back just because of this.   We've been in touch with 
Sherry, and she seems willing to help us out.

Regards& enjoy yourself -

David Skolnik




At 02:48 PM 12/24/2006, you wrote:
>In looking at these pictures, I think we might be missing why the
>Tokiwa's checks work better than the Steinway checks. I don't think it
>is the check. I think it is the wire, not how thick it is, but how much
>of it is being allowed to "bend" and catch the tail. Look at the bottom
>of the wire, and you will see that the knurled part of the Steinway
>wire is almost twice as long of as the Tokiwa's. With this much wire
>stuck in the key,and less of it outside, the wire is not allow to give,
>and accept the hammer coming down. That is why, I think, when I raised
>the checks on my D, the hammers were able to check, because there was
>more wire to bend and give. Does this make any sense?
>
>Wim
>
>
>Quoting Israel Stein <custos3 at comcast.net>:
>
> > At 11:00 AM 12/23/2006, caut-request at ptg.org wrote:
> >
> > >Too bad you can't send some pictures.  While not conclusive, it
> > >would be interesting.
> > >
> > >Happy holidays
> > >
> > >David Skolnik
> >
> > Well, I got ambitious and took some pictures. Front view, side view,
> >
> > and side view with the approximate angle when installed in the piano.
> >
> > I hope they are useful. JPG files are attached. Steinway current
> > style - red felt, Tokiwa's old-style Steinway - green felt.
> >
> > Israel Stein
> >
> >
>
>
>Willem Blees, RPT
>Piano Tuner/Technician
>School of Music
>University of Alabama
>Tuscaloosa, AL USA

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