no hammer rise

[Will Truitt]

Hi David:

 

If my memory serves me, you said in an earlier post that this was a Kohler
and Campbell, which would make it a Samick product.  When you go back to the
piano, I would take string height measurements, hammer center pin height,
and calculate what the hammer bore should be.   Then compare that to the
hammer bore that you measure off the hammer itself.  Years ago I was
regulating a small Samick grand that just didn’t want to regulate right.
The hammer bore was off by about ¼”.   A tell tale sign of this kind of
trouble will be that, when you have set the blow distance to roughly the
factory spec, the knuckle core and the jack don’t line up in that straight
line we all like to see.  

 

It’s never a bad idea for any regulation job you are doing on a “new to you”
customer piano to do a quick and dirty hammer bore distance check prior to
beginning your regulation sequence.  It helps you avoid the creeping
“There’s something rotten in Denmark “ feeling that is then followed by
“Oh, s..t”, when you realize that you are 2/3 of the way through the job and
the piano’s geometry problems have painted you into a corner.  When you have
hammer bore distances that are gonzo like the above, the only solution is a
new set of properly bored hammers, which means your labors have been wasted.


 

When at let off, check to see what the distance from the bottom of the
hammer tail to the top of the back check is.  If the bottom of the tail is a
half mile above the top of the back check, that’s another warning sign.  

 

Will Truitt

 

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of David Nereson
Sent: Friday, June 13, 2008 1:18 AM
To: Pianotech List
Subject: no hammer rise

 

Thanks for all the responses.  The action has been completely regulated and
everything is as it should be except the hammer rise.  

    Got busy all the sudden and haven't had time to double-check the things
in your responses (I don't have the piano in my shop), but will soon.

    I'm quite certain that neither the hammers nor rep. levers are pinned
too tightly, and I know the drop is only 1/8" or less.  Even when the rep.
springs are compressed to their max. (made strongest), there's still no
rise.  

    I'll have to check the backchecks again, but I know checking distance is
in the right neighborhood.  

    Thanks.  

    --David Nereson, RPT 

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