Spring Gauges

[Yardbird47@aol.com]

Micheal Wathen rote (Two Pianos---):
<<The centers were all measured with spring type gauge manufactured
by P.K. Neuses.  I have no information on the accuracy of this
instrument but I believe it to be reasonably accurate.>>

I love these guages. Originally I found the set of three of them (10-0-10,
0-50, 0-150g) in the Jensen Catalog, and told Schad Jr. about them at the '80
Penn State convention. People scoff at them presumably because they don't
cost at least $100. But I took them 10-0-10 to a lab scale reading in .01g
(with optically magnified window), and carefully pressed to spring downawrds
on a block in the middle of the scales platen. (The spring is accurate when
applying pressure normal to the surface, and you need the block, tarred of
course, to allow you room to pivot the guage's frame downwards as you keep
the spring normal to the block.) At each .1g step of the scale I would check
back to see if, interpolating between the guage's .5g increments, I was happy
with the spring's location on th guage's scale. I was quite satisfied.
What I also tried with the 10-0-10 was to relocate the spring's zero point at
one end of the scale, so that I had a 0-10-20 scale. At that point, the
guage's scale lost accuracy in the 10-20g range, not because of any
non-linearity in the spring but because the radii of the scale and that of
the spring's sweep didn't have the same center. So, back to a 10-0-10. Heck,
I already had the 0-50.
The 0-50 could read some damper levers, but not by the time you'd added the
wire,head and felt on top. The 0-150 I was hoping to measure escapement
weight with, but that's a whole 'nother story.

Bill Ballard, RPT   "No one builds the *perfect* piano, you can only
                  NH Chapter                  remove the obstacles to that
perfection during
                                     the building."    ...........LaRoy
Edwards