<!doctype html public "-//W3C//DTD W3 HTML//EN">
<html><head><style type="text/css"><!--
blockquote, dl, ul, ol, li { padding-top: 0 ; padding-bottom: 0 }
--></style><title>Re: Lowell Component Downbearing
Gauge</title></head><body>
<div>At 9:28 am -0500 14/5/07, David Skolnik wrote:</div>
<div><br></div>
<blockquote type="cite" cite>...Dale's gauge seems to have a
comparable vulnerability in its 'blindness' to the bridge surface and
the anomalies that can be introduced. For example...a bridge
surface which angles upward (creating "negative front
bearing"), then has the string return to a point exactly on a
line with the extended straight line of the sounding length of the
string, would show no bearing, yet it would be present, albeit in a
distorted form.</blockquote>
<div><br></div>
<div>Hello David,</div>
<div><br></div>
<div>Do you mean something like this, where the pin is held in contact
with the bridge only by the downdraft from the angled front pin?
If so, then without the pin there would be no angle and thus no
downbearing. As it is, the forces are acting to pull up the
front of the bridge and push down the back, which results in a moment
about the centre of the bridge top and no net downbearing. Surely this
is not a well piano.</div>
<div><br></div>
<div><br></div>
<div align="center"><img
src="cid:p0624083fc26e77d86d3f@[10.0.0.1].1.0"></div>
<blockquote type="cite" cite> The Lowell would show that
information, however, without the additional information from an
Erwin-style tool, it would be difficult to determine the
net-effect.<br>
</blockquote>
<blockquote type="cite" cite>Would you be satisfies with Lowell gauge
with a better vial, wider distance range, with magnetic feet? What
would it's shortcomings be at that point? besides price?</blockquote>
<div><br></div>
<div>I can only judge the Lowell tool from reading the patent and
looking at the accompanying drawings, since I haven't seen one or even
a photo of one. To me it looks and sounds far too complicated
and fiddly and thus, since it is not built as a precision instrument
with a price to match, prone to error. A far simpler and more
robust tool can, I am sure, do a better job and return more precise
results more quickly. I can't really work out the point of the
bubble vial at all, since all the measurements are relative if we are
considering only downbearing.</div>
<div><br></div>
<div>All that is needed in principle is a rigid bar or tube with two
legs slidable on it and one non-sliding leg at one end whose height
can be adjusted by means of a screw fixed to a dial. Supposing
the screw to have a pitch of 1 mm. and the dial to be 32 mm. in
diameter with 100 marks spaced at 1mm round the perimeter, then each
millimetre on the dial will indicate 1/100 mm., or even more accuracy
could be got with a finer thread. The measurements can then
easily be used to calculate the angle and the downbearing. Such
a tool can be made extremely light, strong and durable and the only
calibration it requires is to zero the dial when all three points are
touching a perfectly flat surface.</div>
<div><br></div>
<div>I have no interest in depreciating the Lowell tool and I might
change my mind if I actually had one to play with and get the feel of,
but in all design I like the utmost simplicity combined with great
ease of use and excellent function.</div>
<div><br></div>
<div>JD</div>
<div><br></div>
<div><br></div>
<div><br></div>
<div><br></div>
<div><br></div>
</body>
</html>