Lowell guage

[Paul]

Thanks, Ron. I needed it, too!

Paul Chick
----- Original Message -----
From: Ron Nossaman <RNossaman@KSCABLE.com>
To: <pianotech@ptg.org>
Sent: Friday, October 12, 2001 6:22 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
>