About Checking

[William R. Monroe]

The tail shape is right on (thanks Renner).  I had the Renner shop do the
shaping, arcing, roughing bit.  I'm not ready to tackle hanging hammers yet,
so I had them hang a set for me on new shanks, flanges, with all the prep
work, leaving me to concentrate on regulation stuff.  Any other ideas from
the "list" as to what would cause this checking problem?

William R. Monroe
Madison, WI
Assoc.
----- Original Message ----- 
From: "David Ilvedson" <ilvey@sbcglobal.net>
To: <pianotech@ptg.org>
Sent: Monday, November 08, 2004 9:55 PM
Subject: RE: About Checking


> Go to http://ptg.org/    Click pianotech archives and search hammer
checking.   Make sure your hammer tail shape is right...i.e.  a 2&1/2 to 3
inch radius.   Do the tails come down flat and then angle sharply in at
about 25 degrees?  Wrong shape=poor checking.  The simpliest thing to do
when you have existing hammers to deal with is take ruler or better yet a
protractor and look at what circle with a 3 " radius looks like.    That
curvature shape is what you are after, what the shape of your hammer should
look like from the side.   Clamp a section of hammers up on a block so they
are above the backchecks and you won't put undue stress on the centers.
Take a drill with a sanding disk and 60 sandpaper.   If you carefully run
along the hammer tails you can duplicate that shape and make a BIG
difference in checking.    1st even out the ins and outs of the hammer tails
coming from poorer hammer hanging, then start bringing down the angle,
smoothing it out.
>
> David I.
>
>
> ----- Original message ---------------------------------------->
> From: "William R. Monroe" <A440WRMPiano@tm.net>
> To: Pianotech <pianotech@ptg.org>
> Received: Mon, 8 Nov 2004 20:11:55 -0600
> Subject: About Checking
>
> >Hi List,
>
> >I've a small grand that I'm regulating (mine) and I'm struggling with
> >checking.  Just finished regulation, and everything works well except
> >checking.  Checking is nice and even throughout from a medium blow on up
at
> >15mm.  I've double checked things like:  repetition spring tension -
> >definitely not too strong; escapement - jack is clearing knuckle
> >sufficiently; backcheck height and angle seem right.  I guess my thoughts
> >now lean towards, maybe backchecks are too low?  I can get checking on a
> >soft blow by decreasing the checking height from 15mm to about 8 or 9,
but I
> >just don't like it that close.  Thoughts? and Thanks.
>
> >William R. Monroe
> >Madison, WI
> >Assoc.
>
>
> >_______________________________________________
> >pianotech list info: https://www.moypiano.com/resources/#archives
>
> _______________________________________________
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>