[CAUT] stack fit to keyframe

[Bob Hohf]

Thanks for the kind words, Ric.  "Action Elevations" appeared in the May,
June, August, and September 2000 issues of the Journal.  The main point of
the series was that for a given balance rail elevation, there is a single
optimum string height for an action.  I will be teaching the topic as a
class for the first time at the Chicago School on Nov. 10.  It will be part
of an all-day seminar including "Stress and Resonance" and "Keyweights and
Touch".

Bob Hohf

> -----Original Message-----
> From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org]On Behalf Of Ric
> Brekne
> Sent: Sunday, September 10, 2006 6:46 AM
> To: caut at ptg.org
> Subject: [CAUT] stack fit to keyframe
>
>
> At 1:49 pm -0700 9/9/06, David Ilvedson wrote:
>
> Jd offers a very good reply here.  I might throw in that Bob Hohf wrote
> an excellent article series a couple three years back. Action Elevations
> I think it was called.
>
> Its well worth reading.
>
> Cheers
> Ric B
>
>  >When I come across a grand action stack that doesn't fit flush to
>  >the keyframe, I have typically thought the keyframe should
>  >beÊshimmed to fit...
>  >
>  >What I'm concerned about:   This action/keyframe is perfectly mated
>  >to the keybed as it is...I'm wondering if I might not change
>  >something not necessarily for the better...????
>
> Any shimming or shaving you do is unlikely to change the mating of
> the key-frame to the key-bottom.  The main question is whether the
> line of the hammer-centres (and of the lever-centres) is straight and
> parallel to the key-bottom, or the underside of the wrestplank, which
> ought to amount to the same thing.  Then there is the question of the
> height of the hammer-centre line, the differential boring of the
> hammer-heads etc.  It is quite easy to get things wrong unless the
> whole geometry of the action and the strings is taken into account
> and the best makers are not guaranteed to get it right in the first
> place once the drawing board fades into history.  I recently had to
> make significant adjustments to a Hamburg Steinway of 1923 which can
> never have been properly set up.
>
> JD
>