A little bit of an anti-climax. I read the original damper pressures (weight plus springs), and guessed that what I was looking at was the factory's straight line from #1 to #54, with 110+ years of use, plus a rebuilding in the Boston area nearly 50 years ago. What's more, with pressures just a fraction of what the Renner manual calls for, the dampers were working fine. So I decided too disable the springs to see whether their pressure was even necessary. NOT! The tray weight itself would even still return nicely with the coil spring removed (although I did need the leaf spring on the trap lever).
Throughout the system, it passed the pianissimo and fortissimo staccato tests, and the fortissimo test holding the key down for a second so that its return would be from a dead stop. My first chance to try setting spring pressures, and I didn't even get a chance to do it.
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William Ballard RPT
WBPS
Saxtons River VT
802-869-9107
"Our lives contain a thousand springs
and dies if one be gone
Strange that a harp of a thousand strings
should keep in tune so long."
...........Dr. Watts, "The Continental Harmony,1774
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Original Message:
Sent: 12-14-2019 15:00
From: William Ballard
Subject: Damper Underlever Springs, Simplified & Redux
Has anyone done initial measurements for what existed at guidepoints, and seen something like this? #1 should be ~35.
#1: 16.3g
#30 (mid-scale): 16.2g
#54 (end of springs): 12.4
#55 (no spring): 6.0
These confuse me; of three readings which don't make sense, which should I choose to evaluate the other two? #1 @ 50% of conventional, #2 the same as bottom of the scale, or #54 which is double what it should be.
Any ideas on this? I'm just going to do a straight tape from #1 as is through a #54 (to match #55).
TIA
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William Ballard RPT
WBPS
Saxtons River VT
802-869-9107
"Our lives contain a thousand springs
and dies if one be gone
Strange that a harp of a thousand strings
should keep in tune so long."
...........Dr. Watts, "The Continental Harmony,1774
+++++++++++++++++++++
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