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<DIV><FONT face=Arial size=2><EM>"...with special attention given to key bushing
friction control."</EM></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>What do you recommend for key bushing friction?
Minimal/near-zero without inducing slop? Some number of grams friction? What are
the advantages to having near-zero and having some amount? Thanks.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Terry Farrell</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>----- Original Message ----- </FONT></DIV>
<DIV><FONT face=Arial size=2>> When one studies piano friction weights
(D-U)/2 they find that, with <BR>> uniform flange frictions, on average
the friction weight drops by about 4g <BR>> from bass to treble.
This of course is due to the fact that hammers are <BR>> heavier in the bass
and push the parts together with more force causing <BR>> more friction in
the bass end.<BR>> <BR>> Many of us sort friction with high in the bass
and low in the treble and <BR>> this exaggerates this natural tapering of
friction even more. So what <BR>> you've done is to make friction
weight even less tapered than normal by <BR>> putting the lower friction
hammer flanges in the bass.<BR>> <BR>> One finds that a change of one gram
of rotational friction measured at a <BR>> 32mm radius on the hammer flange a
gram will create a difference in the <BR>> friction weight of about one gram
which means a change of 1g in both down <BR>> and up weight.<BR>> <BR>>
So if your sort yields say one gram rotational in the bass to say 5 grams
<BR>> in the treble then your offsetting the natural decrease of friction
bass to <BR>> treble of 4g with an increase bass to treble of 4g giving a
more or less <BR>> uniform friction weight bass to treble so if the down
weights are weighed <BR>> off to be a uniform level bass to treble the up
weights will be uniform as <BR>> well.<BR>> <BR>> If, in this case, you
sorted with high friction in the bass to low in the <BR>> treble the up
weights in the bass would be much much slower than in the <BR>> treble, with
a uniform down weight.<BR>> <BR>> If your going to sort by friction I
think it makes more sense doing what <BR>> you've done because it creates a
more consistent friction weight bass to <BR>> treble which in turn creates
the possibility to weigh off to a more <BR>> consistent down weight and up
weight bass to treble. I'm sure that many <BR>> pianists would notice
and like that kind of set up.<BR>> <BR>> I actually prefer, in the case of
shanks, to sort by shank strike weight <BR>> then working the flange
frictions to be as uniform as can be from bass to <BR>> treble, with special
attention given to key bushing friction <BR>> control. Friction comes
and goes but weight is pretty constant by <BR>> comparison...<BR>>
<BR>> Whew!<BR>> <BR>> David Stanwood</FONT></DIV></BODY></HTML>