no hammer rise

[Dean May]

    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 

 

 

1/8 inch is a generous drop. I like to set for minimal drop. Seems to me
like every time I used to have trouble getting hammers to rise either my
drop was lower than I thought it was or the checking was too high. 

 

Did you bench regulate or in the piano? If on the bench I'd be very suspect
of your settings, particularly letoff and drop (unless you use the Spurlock
tool illustrated below). 

 

Set your letoff on a sample note in the piano- C4 would be a good one. Set
it to the thickness of the string, or about 1 mm (it helps sometimes to
shine a flashlight across the strings. Pull the action and reset the drop on
that C4. Hold down B3 so you can have a visual reference. Set the drop
within 1 mm (1/32") of your let off. Now check your hammer rise.

 

 

I really like the Spurlock regulating jig. Set the letoff on the end notes
of each section, then it's a snap to do the rest and letoff on the bench.
http://www.spurlocktools.com/id24.htm

 

You set the height of the jig so the end notes just barely click against the
rail at let off. Then set every other note in the section so they also just
barely click.

 

For drop hold the key down and turn the screw up until the hammer barely
comes off the jig rail. That is drop set to the letoff height. Turn screw
down slightly so hammer is back on rail and your drop is now set to just
below letoff (assuming you have key dip set on the bench to match what it is
in the piano). 

 

let-off jig in use

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

let-off jig

 

 

 

 

 

 

 

 

 

 

 

 

 

(pictures from Spurlock's website)

 

 

 

 

Pull the jig, rough in checking and repetition spring tension and that
section is well on the way to being regulated. 

Dean

Dean May             cell 812.239.3359 

PianoRebuilders.com   812.235.5272 

Terre Haute IN  47802

 

  _____  

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of David Nereson
Sent: Friday, June 13, 2008 2:18 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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