Lowell guage

[Carl Meyer]

Ron, I'm asking you this question since you are largely responsible for
encouraging me to get carried away (according to some) in modifying this
Emerson piano for the vertical hitch pins.  I saved this post about the
Lowell gauge.

My plans are to string the plain wires, bring it up to about one step flat
and then adjust the down bearing.  What angle in the different sections
should I shoot for under those conditions?
It's easier to adjust before installing the bass strings.  Then I'll string
the bass and do likewise.

 Your recommendations and comments welcomed.  Thanks.

Carl Meyer  Assoc. PTG
Santa Clara, California
cmpiano@attbi.com



----- Original Message -----
From: "Ron Nossaman" <RNossaman@KSCABLE.com>
To: <pianotech@ptg.org>
Sent: Friday, October 12, 2001 3:22 PM
Subject: Re: Lowell guage


> >Hi list,
> > Does anyone still have the original lowell downbearing gauge
> >instructions ,  that tell what the scale markings are supposed to be
> >calibrated to?    For fun I went to the Baldwin class at Sparks and the
> >Baldwin people disagreed with Mr. Lowell as to the actual degrees that
> >the bubble markings corresponded to.  But I can't find my notes,
> >soooooo...............
> >
> >Thanks
> >
> >Dale Fox
>
>
>
> Here you go Dale, Tom sent me this some time back.
>
>
> In brief, the thousandths of an inch quantities represented by the linear
> increments (division lines) on the gauge are the rise or fall (vertical
> dimension) per inch of length of piano string. So, to give an example, if
> your rear string length
> was 3" and your gauge measurement was .009", then the difference in
elevation
> between the top of the bridge (a reference at zero), and the rear string
> rest would be 3" x .009" or .027". Very simple math. These dimensions can
> be converted to degrees of angle by multiplying 1/6 degree times the
number
> of division lines the bubble has crossed. Crossing six division lines
would
> mean 1 full degree of string angle. More simple math. To determine the
lbs.
> pressure
> from the net downbearing measurement multiply the net bearing in
thousandths
> of an inch by the tension of the string. For example, a string of 200 lbs
> tension, deflected by the bridge so that a net downbearing measurement of
> .018" (1 degree) is created, will produce a downbearing pressure of 3.6
lbs.
> (200 x .018). More simple math. Incidentally, the bridge is pushing up at
> the string 3.6 lbs. at the same time the string is pushing down on the
bridge,
> thus creating a static equilibrium, like a depressed spring. An
> understanding of trigonometry is unnecessary, but can't hurt anyone.
>
>
> Ron N