1890s WNG Action Geometry

[gordon stelter]

I'm kind of baffled that an 1890's Knabe would have a
WN&G action. All the Knabes I've ever seen have Knabe
actions, or AMPICO actions. I'm not doubting you, but
are you sure it's original?
     Thump

--- Overs Pianos <sec at overspianos.com.au> wrote:

> >Phil Bondi and I dove into an 1890s WNG action from
> a 6' 4" Knabe 
> >today to try and straighten out some basic action
> geometry. We 
> >haven't got all the kinks worked out yet, but we
> seem to be getting 
> >there. With only a large capstan move and removal
> of a couple leads, 
> >we went from an action ratio of over 6.0 down to
> 4.9. DWs went from 
> >60+ to 50 and less (I know, too light) and BW in
> the 36 to 40g 
> >range. We have a lot of work to do yet, but it
> seems the capstan 
> >move described below has gotten us into the right
> ball park anyway.
> >
> >Most notable was a very large capstan move that we
> will likely keep 
> >(unless someone so kindly informs us of a potential
> problem the 
> >change might induce). The photo below shows the
> original capstan in 
> >the background. The forward key had its capstan
> moved 10mm forward 
> >and 11mm lower. The middle key had its capstan
> moved 13mm forward 
> >and 12mm lower. The second photo shows the modified
> wippen 
> >heel. These lower positions put the capstan right
> on the magic line 
> >at half blow. The capstan/wippen heel interface
> went from a 
> >traveling, grinding, sliding affair and a note with
> 17g friction to 
> >a perfectly interfacing union with no apparent
> sliding and a note 
> >with 9g friction. We were amazed at the improvement
> in friction and 
> >interface movement.
> >
> >This strikes me as a rather drastic capstan move.
> Has anyone else 
> >run across an action that needed such a large
> capstan move?
> 
> Yes.
> 
> >  As our action ratio is down to 4.9 and key ratio
> is down around 4.8 
> >with the 10mm forward capstan migration, we may
> move it back just a 
> >few millimeters. But still it seems large. Is there
> some hidden 
> >pitfall I'm not seeing?
> 
> I doubt it.
> 
> >  Comments?
> >
> >Terry Farrell
> 
> It seems to me that you guys are heading in the
> right direction with 
> this action. The balance pin lines must be set
> further back towards 
> the key fronts than usual with this keyboard, to
> require such a 
> positioning of the capstans. However, if the jack
> clears the roller 
> sufficiently with the key dip and hammer blow
> distance that your 
> looking for, it doesn't matter where the
> capstan/heel location falls 
> relative to the wippen body (but it must be on the
> line of centres at 
> half blow, which you have already addressed). The
> regulation 
> parameters are all that matters. The down/up weight
> figures you quote 
> prove that the setup you've come up with is going to
> yield a good 
> result. Look forward to hearing what you end up with
> in final figures.
> 
> As a postscript, we had a wonderful time in the US,
> at Rochester and 
> later in Boston. I hope to write a report-post on
> our trip very soon 
> for the list. Some of you have emailed me since our
> return to Sydney 
> and I haven't got around to replying yet, for which
> I apologise. Will 
> attend to this also very soon.
> 
> Best regards,
> Ron O.
> -- 
> OVERS PIANOS - SYDNEY
>     Grand Piano Manufacturers
> _______________________
> 
> Web http://overspianos.com.au
> mailto:ron at overspianos.com.au
> _______________________


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