[pianotech] key ends and damper timing

[David Love]

The important part is that they pick up the dampers at the same time which
(more importantly) means that the damper shut off with the keys will be
timed uniformly.  The final position of the key ends at the end of the
stroke and uniform clearance at the upstop rail is much less important if
you have to choose.  Assuming all the other regulation specs are checked
first and that everything is in order especially with respect to the key
height relationship between sharps and naturals (perhaps a big if), I would
shim the key ends so that when you put on the key end felt they are all the
same height when the keys are at rest.  That will insure that the damper/key
pick up and shut off will be in sync.   

 

 

 

David Love

www.davidlovepianos.com

 

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Gene Nelson
Sent: Sunday, May 31, 2009 3:03 PM
To: pianotech at ptg.org
Subject: [pianotech] key ends and damper timing

 

Hello list,

After leveling keys and setting dip accurately and doing some regulation I
went to the key ends to begin the process of taking location marks for a new
back action.

Striped off the old key end felt and found that the key ends of the sharps
are less in elevation from the key bed than the naturals. Did not notice
this before striping off the key end felt but was not really paying
attention and the felt was badly worn anyway. 

At full key dip they become much closer to equal elevation from the key bed
- that is in the bass. As the keys get shorter in the tenor and high tenor
sections the key ends are much closer together at rest and the sharp will
lift higher in elevation than the naturals.

The factory must have done this??

The question is - what is the best option for damper timing.

1: I could fully dip all keys and trim the key ends so that they are all the
same elevation from the keyed. This will allow a nice unstop rail
adjustment.

The down side is that the damper lift levers will have different lost motion
with the key ends.

Appears to me that if the sharps pick up the lift lever slightly different
than the naturals it may not be so noticeable if it was consistent.

2: I could leave it the way it is and the damper levers will generally get
picked up at around half key travel but sharps and naturals at full key dip
will have their dampers at different elevations making the unstop rail
higher than desired.

Someone at the factory had something in mind and I am missing it.

Any help would be appreciated.

Gene

 

 

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