Hi Jon,
I am always eagerly awaiting to see what you come up with next. But, i think there is an accrued error that's built in to your design.
Two Reasons:
First you set the tool on the windings and place the dial onto the top of the core. This gives you a false "zero" and the error get worse as the windings get larger.
Second, by the tool blanketing several strings the individual strings inaccuracies get covered over. Iv'e seen big angle changes from neighbors strings as i'm sure you have too.
Here's my latest and last Lowell type gauge (as i see no way to improve it after 4 modifications). It features a large bubble with 1 degree lines. So easy to read. And i have made several feet for any situation, and the height goes over any capo bar. Its spring loaded so it hugs the adjustment bolt. The bubble has a slightly slower fluid that makes seeing the smallest angles a joy. And its easy to get one at Home Depot.
Regards
-chris
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Chernobieff Piano Restorations
"Where Tone is Key, and Mammoths are not extinct."
865-986-7720 (text only please)
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Original Message:
Sent: 08-03-2022 22:02
From: Benjamin Sanchez
Subject: Down Bearing Gage
That's cool Jon, thanks for sharing!
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Benjamin Sanchez, RPT
Piano Technician / Artisan
(256) 947-9999
www.professional-piano-services.com
Original Message:
Sent: 08-03-2022 11:51
From: Jon Page
Subject: Down Bearing Gage
After a few proto-types, here's what I settled on. I got this idea from John Hartman's (I think) gage, (Rocker Arm).
Using a spreadsheet designed by Alan McCoy; at 80 mm, a half of a degree has an offset of .027". The outer ring markers are set to .027".
I place the gage on the speaking length (DB 1), then move the body of the gage to the front pin and take a reading (DB 2).
I place a shim under the twisted portion to bring the bearing into line.
During this rebuild, washers were placed on the hitch pins to alleviate excessive down bearing. I can micro-adjust this db now.
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Regards,
Jon Page
mailto:jonpage@comcast.net
http://www.pianocapecod.com
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