Action Geometry

Richard Brekne Richard.Brekne@grieg.uib.no
Thu, 28 Sep 2000 19:08:25 +0200


Case Study.. just got an action in for rebuild. Its going to need new
hammers and rollers (knuckles), action felt, bushings, centers (maybe new
hammershanks). Its a J.L. Duysen serial number 12517 which the owner says
was built in 1913.

Couple things of note.. ivoriers are white as can be and still shinning
brightly. No cracks anywhere to be seen in the soundboard / bridge /
pinblock. Its a three quarter plate with the pin block completely exposed..
just a three extensions of the plate ...er...whateryacallem...grin..
struts..! thats it..:) to hold the thing down. Its at A436 and hasnt been
tuned for 11 years.

OK... nough of all that. Its the action I am first and formost concerned
with. This is strange indeed. Its very heavy..clunckly heavy. The spread is
wide.. about 5 mm at note 88 and about 2 mm at note 1. Cant move the
whippen rail in much or the front/top of the whippens will start hanging on
the hammer rail. This looks like a great chance to start getting really
familiar with some basic action redesign..  :):)

I'll get my stanwood measure kit out fromt the UiB tommorrow and get some
basic samples measured and also measure some action part distances. Rollers
for example look like they are a long way from the hammer centers.

Anyways I'll get all this up and posted by Saturday and see what you all
think about this puppy. Would be fun to do this job along side of the
advice and counsel of the esteemed and emminently learned subscribers of
this list...:)

--
Richard Brekne
RPT, N.P.T.F.
Bergen, Norway





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