[CAUT] Capstans to Tray

[Keith Roberts]

Fred,
One thing I tried when the screw had bit into the wire too much and it
wouldn't stay where I wanted was to pull the damper and run a file across
the bad spot. It suddenly becomes obvious; I mean the bad spot highlights
itself. Sometimes you might want to dress the end of the screw. It can have
a cam like action or edge that cuts into the wire and twists the wire as the
screw is tightened.

Keith Roberts



On 3/24/07, Fred Sturm <fssturm at unm.edu> wrote:
>
> Hi Ric,
>    Yes, I've fooled with a bean bag. Actually made myself one and put a
> bit
> of sand in it instead of beans, though you want to go thin and light with
> sand (it can get so heavy it will compress the felt too much, and force
> the
> trichords down farther than they will normally seat). But sand set the bag
> more inertly and evenly on the damper heads, to my way of thinking.
>    Bottom line, though, I decided I didn't like it. It _seems_ like it
> would give more even control, but it doesn't, at least at a fine level.
> Better to just deal with the actual weight of the dampers, and sensitive
> fingertips. If you have all the wires loose, and all the levers resting on
> the tray or jig, just tightening them with a light touch where they lie
> gives me as good a starting point as with the bag on top, better most
> often.
>    Kawai techs have a technique similar to Yamahas (though I think the
> capstans are on the tray - I don't do enough to remember between all the
> Asian variants), but they do use them after that initial straightedge set
> up
> for minor tweaking. We're talking up to a quarter turn, probably less.
> Which
> is far more efficient than loosening the screw, moving the damper wire
> that
> miniscule little bit, tightening, the having to twist/align, then find you
>
> moved a wee bit too much or not enough, repeat. If the wires are new and
> the
> screws haven't been over-tightened by somebody, it goes pretty well, but
> if
> there are dents and bends from the screw, well, many's the time I wish
> there
> was a capstan to turn for that last bit.
> Regards,
> Fred Sturm
> University of New Mexico
>
>
> On 3/24/07 7:10 PM, "RicB" <ricb at pianostemmer.no> wrote:
>
> > Hi Fred..
> >
> > Yes. Getting the levers at even height is the immediate goal here (what
> > you refer to below).  That and making sure this height yields proper key
> > lift timing.  We used their aluminum straight edge tool for key leveling
>
> > on the underside of the levers to get a straight line, adjusting
> > capstans as necessary. But whatever gets you there...  BTW the Spurlock
> > bean bag idea looks kinda interesting... has anyone tried one of these ?
>
> >
> > Cheers
> > RicB
> >
> >
> >    But I think I now see that what you do is set samples (only
> tightening
> >   those wires, the others all being loose), then raise the lift tray
> >   to meet
> >   the samples (and block it in place), then adjust all the other
> capstans,
> >   which are resting on the lift tray, so that the bottoms of the
> >   underlevers
> >   are in line with the straightedge (the capstans are raising - or
> >   lowering -
> >   their respective levers to be in line, with the lift tray as the
> >   "gauge" or
> >   base, and the samples as the reference). Now you tighten all the other
> >   wires, and proceed with standard twisting, tweaking and whatnot.
> >
> >
>
>
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