Lowell Downbearing Gauge

[Roger Jolly]

Hi Avery,
         The great advantage of the compound gauge, is that it can measure
bridge roll, and not just net bearing, the job is lot easier if you use
both the 3 legged dial gauge and the compound gauge in tandem.
  If you have zero bridge roll, then 2 degrees deflection in the extreme
treble sections going to 1.5 degrees in the centre and bass. This
translates to about .025" in the treble and about .015" in the centre
section. Make your dial gauge measurements at the mid point of the bridge
pins for consistancy. By setting the end strings of each section you can
use the Jon Page taut line principal, to set the bearing of the rest as
your strings. Make sure you firmly seat the strings as you go as it will
give you the maximum consistency with little or no corrections when the
piano is at pitch. Another tip is that it is easier to tap a string down
when at pitch than to raise them. I made up a simple tool, just drill a
hole, clearance size of the hitch pin, in a piece of bar. When you tap the
string down it will be level on both sides of the pin.
  If you have bridge roll, Upward deflection on the bridge from the
speaking length, then the sound board should be checked for bearing, and
the bridge should be sanded down to correct, but that is whole new can of
worms.
  Hope this helps
Roger





At 02:41 PM 7/9/98 -0500, you wrote:
>List,
>
>   Is there anyone around right now that has experience using the Lowell
>Gauge? I got one to restring the Baldwin L and I'm having trouble
>figuring out how to use it.
>   If anyone can help me, contact me privately if you wish, as this
>probably isn't a subject of widespread interest.
>   If the address shows up as a link in your program, just click on it.
>Thanks.  mailto:atodd@uh.edu
>
>Avery
>
>
>
Roger Jolly
Balwin Yamaha Piano Centres.
Saskatoon/Regina.
Canada.