About Checking

[Farrell]

I've observed checking problems when the rep springs were too tight and/or
the jack was not clearing the knuckle.

Terry Farrell

----- Original Message ----- 
From: "William R. Monroe" <A440WRMPiano@tm.net>
To: "Pianotech" <pianotech@ptg.org>
Sent: Tuesday, November 09, 2004 9:41 PM
Subject: Re: About Checking


> Also tried varying the backcheck height, which showed no noticeable
> improvement with either higher or lower backchecks.  Also tried changing
the
> backcheck angle - again no improvement one way or the other, hammers
simply
> will not check on soft blows.
>
> Lost in Wisconsin:
> William R. Monroe
> Madison, WI
> Assoc.
>
>
> ----- Original Message ----- 
> From: "William R. Monroe" <A440WRMPiano@tm.net>
> To: <ilvey@sbcglobal.net>; "Pianotech" <pianotech@ptg.org>
> Sent: Tuesday, November 09, 2004 7:32 PM
> Subject: Re: About Checking
>
>
> > 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.
> > >
> > >
> > > >_______________________________________________
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> > >
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> > >
> >
> >
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> >
>
>
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