[pianotech] Action Ratio Measuring redux

[David Love]

Which action measurements did you use?

David Love
www.davidlovepianos.com


-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Brown, David
Sent: Friday, September 28, 2012 4:42 AM
To: pianotech at ptg.org
Subject: [pianotech] Action Ratio Measuring redux

All-

Sent this yesterday with attached photos, but no luck. Here is the message-

Well , here are results from a new Renner action model. After measuring the
action parts themselves , I ended up with several different possible
combinations depending on which measurements I used. So.. I figured, let's
see what displacement gives me, and then which combinations of numbers
roughly equal what I got with displacement. I include some photos of that
set up. Not the actual measuring, just an idea of what the set up looked
like. Ed Foote's idea of a needle in the hammer worked very well. I got 37
mm of hammer travel for 5.875 mm of dip giving me a ratio of 6.297, or 6.3.
Using  combinations of action measurements, the closest I could come was
either 6.49 or 6.10 , right on either side of the displacement, but still
not close enough.Add them up and divide by two gives me 6.3., but that
seemed like fudging.

Entirely too much time spent on this today, but very informative. I will
continue this on a B action scheduled for a new keyset and parts at the end
of this semester.Big thanks to all who shared and helped.

Best-

David

David C. Brown RPT
Piano Technician
Division of Music
Meadows School of the Arts
Southern Methodist University
Dallas Texas 1-214-768-3976