Kawai heavy action

[David Love]

I wouldn't rule out a geometry change in terms of moving the capstan.  It's
a pretty fast job, faster than installing assist springs, and cleaner than
thinning the hammers.  You can test for results by making a dummy ,movable
capstan out of a cut off capstan, a block of wood, and some two sided tape.
Measure the length of the existing capstan from the top of the key to the
wippen cushion.  Take an old capstan and cut off the threaded portion so
that the overall length is just less than that measured distance.  Drill a
hole in a small thin block of wood (I use a piece of those dividers that
Renner puts in the shankflange boxes) that will accept the cut-off capstan.
You'll still be able to adjust it slightly, but the shortened threaded
portion won't allow you to adjust it very far.  Put the two sided tape
under the block of wood to secure it on top of the key.  Take a capstan out
of one note (I like to use note 40) in which you have measured the balance
weight ((DW + UW)/2), insert the dummy and move it around until you get the
balance weight you want.  Check the regulation.  Take the key out and use
that as your guide for the new position.  Test your new position on a few
other notes in the bass, low tenor and treble.  You'll want to consider
whether you can add some lead as well by measuring the front weight of the
the sample keys against maximum recommended front weights.  After you move
the capstan reweigh the whole keyboard to even things out.  The whole job
is about a days work and you can use the original capstans after plugging
the holes.    

David Love
davidlovepianos@earthlink.net


> [Original Message]
> From: Fred Sturm <fssturm@unm.edu>
> To: <caut@ptg.org>
> Date: 3/18/2004 6:14:21 AM
> Subject: Kawai heavy action
>
> 	I have a customer with a small Kawai grand from the early 80's which has
a 
> very heavy touch weight. In my experience, this is very common among
Kawai 
> grands of that era (especially the ones sold as Howards), and I expect 
> downweights in the area of 65 gm, upweights around 40 gm. I have serviced 
> several, but never has a customer wanted me to do anything about the 
> weight. They've all either liked the heavy weight, or been too cheap to 
> spend a dime. Until now.
> 	This particular customer has developed "wrist problems" (incipient
carpel 
> tunnel?), and is wondering whether to trade pianos or have this one
worked 
> on. So I need to be able to speak with authority and say
> a) I can take care of this problem. It will cost $X. Or,
> b) You are better advised to trade in and get a different piano.
> 	My sense is that $X needs to be in the "up to $500" range. IOW, action 
> geometry changes are probably out of the picture.
> 	So I wonder if any of you have experience in addressing weight issues in 
> small Kawai's of this vintage, and would be willing to share.
Specifically, 
> I'm wondering if a combination of wipp spring adjustment, adding a bit of 
> lead to keys, and tapering hammers is likely to produce acceptable
results. 
> And whether just springs, just lead, or springs and lead would be enough.
> Thanks,
> Fred Sturm
> University of New Mexico
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