[CAUT] Touchweight, etc.

[Chris Solliday]

Jim is right on here Bob, geometry first, then friction, then touchweight is
the effective order of events but nevertheless I stand by my last post that
the biggest bang for the buck in this type of work will be in marrying the
strike weight to the ratio.  Chris Solliday
----- Original Message ----- 
From: "James Ellis" <claviers@nxs.net>
To: <caut@ptg.org>
Sent: Sunday, July 31, 2005 4:05 PM
Subject: [CAUT] Touchweight, etc.


> I have been reading some recent posts on touchweight and related subjects,
> and I detect much confusion that would be impossible for me to clear up in
> a single post on this list.  I'll just make a few general statements.
>
> In Bob Hull's latest post, his measurements indicate reasonably even
strike
> weight, although it might be a tiny bit heavy in the high treble.
> Down-weight, up-weight, and balance-weight are all over the map.  I don't
> see a column of numbers for the friction component, but I suspect that's
> where the problem is.
>
> Here's how I do it:
>
> I deal with the friction first.  Keys first, absolutely, before anything
> else, then the various action centers.  There is no sense fretting with
> action centers if the keys are binding.  To do a thorough job checking the
> keys, the stack must of off.  You will find things you can't find if the
> stack is on.  After you have the keys all in good shape, deal with the
> action centers.  Don't overlook mundane things like rep levers rubbing on
> adjacent knuckles, and stuff like that.
>
> If the hammer weight taper it reasonably even, the strike weight will be
> also.  If that's the case, and unless someone has been messing with the
> action geometry, and it looks to be in order, I weigh off for balance
> weight, with perhaps a little give and take here and there if there is
> reason to do so.  Friction will go up and down as the relative humidity
> changes, and so will down-weight and up-weight, but balance-weight will
> stay the same.
>
> If the friction component is fairly even; if the strike weight taper is
> smooth, and if the action geomerty has not been screwed up, the other
> measurements will fall right into place.
>
> Unfortunately, I find cases where capstans have been moved around, and
> other things done to the action, when that was not the problem in the
first
> place.  It's very doubtful that an S&S D has the capstans in the wrong
> place, but if that is the case, it's a major problem.  Being poorly
aligned
> with wippen heels is more common.  I would do some very careful checking
> before I started messing with the action geometry of a premium-quality
> grand, but I would do it, and have done it, when I have found such a
> problem - which isn't very often.
>
> More often than not, the problems I find are those that come from the fact
> that somewhere along they way - at the factory or somewhere else - someone
> did a weigh-off while uneven frection was still present.  When that
> happens, you may end up with fairly even down-weight, but everything else
> will be all over the map.
>
> That's the way I do it, and unless someone has screwed up the action
> geometry, or it was flawed in the first palce, it works every time.
>
> Sincerely, Jim Ellis
>
>
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