[CAUT] Capstans to Tray

[Fred Sturm]

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.
> 
>