Mysterious blocking notes <"RE: Mysterious blocking notes"@niflheim.rutgers.edu> (Dec 19, 9:14am)

Newton Hunt nhunt@rci.rutgers.edu
Fri, 20 Dec 1996 10:28:59 -0500


There is one thing that bothers me about this piano.  The capstans are lifting
near the back of the cushion.  Check the following:

1.   Use a thread of similar material and check that the drop screws are in a
straight line.  If they are not the action frame is bent or the stack screws
are pulling the frame off of straight.  I have relocated the stack screws to
straighten such a frame.

2.   Check that the capstans are in a straight line.  If not relocate them.

3.   If all is straight then the capstans are mislocated and they should be
moved.  This involves some math, some weights, some measurements and reweighing
the action.

4.   Counting the lead weights in the bass section should indicate something.
If there are more than four there is a geometry problem.

5.   Check for key chucking, especially sideways.  If the key bounces up upon a
ridge on the bearing this could cause excess capstan travel.

6.   Check for loose pinning or screws in the wippen flanges.  If the wippen
relocate itself this could cause the jack toe to a different location of the
let-off button or the knuckle or the capstan and cause regulation to be
different.

7.   I would also check spread action at each section end to see how closely it
conforms to 4.4400".

8.  Check that the wippen center pin is 3.75" above the key bed, the hammer pin
is 5.75 and that the off frame difference is 2.668".

9.  Check that the knuckles are firmly glued into the shanks and that the
hammer flanges are tight to the rail.

10.  Check the pinning of the jack and repitition lever to varify they have not
free lateral movement at the knuckle.

	Newton
	nhunt@rci.rutgers.edu




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