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<DIV><FONT face=Arial size=2>Hello List,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I'm writing an article about regulating pianos when
you don't have specifications. I'll paste in the simple nuts and bolts of
it below. I'd appreciate your feedback. I know there are some setup
caveats and pitfalls, and some other considerations, but rather than lay all of
them out, I thought I'd wait and hear from you guys about what you see as strong
points, weak points, yeah buts, and any other considerations.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Anyway, here's a simple rough draft:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt">No Regulation Specs?<SPAN
style="mso-spacerun: yes"> </SPAN>Regulate by action ratio analysis!</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"> <?xml:namespace prefix = o
ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt">What if you had no regulation
specs, or the specs you had were not working out.<SPAN
style="mso-spacerun: yes"> </SPAN>Wouldn’t it be great if there was a way
that you could come up with workable specs in minutes?<SPAN
style="mso-spacerun: yes"> </SPAN>Specs that you could custom design
depending on your performance priorities?</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"> <o:p></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt">I got to thinking that if you
knew what the action ratio was on a piano, you could just do the math and come
up with a workable set of specs to regulate it with.<SPAN
style="mso-spacerun: yes"> </SPAN>By making algebraic equations of the
variables, you could even customize a regulation based on what your priorities
were, be it key dip or blow distance.</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"> <o:p></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt">Here’s how it works:<SPAN
style="mso-spacerun: yes"> </SPAN>First you determine what the action
ratio is by measuring how much the hammer moves compared to how much the key
moves.<SPAN style="mso-spacerun: yes"> </SPAN>(Mechanical Action Ratio, or
MAR) You’ll need to move the key LESS than letoff and eliminate lost motion
first, so you can directly measure the hammer movement that results from key
movement.<SPAN style="mso-spacerun: yes"> </SPAN>Now say you move the key
down ¼” and the hammer moves 1 ¼”.<SPAN style="mso-spacerun: yes">
</SPAN>You divide the hammer movement by the key movement and discover an action
ratio of 5:1.<SPAN style="mso-spacerun: yes"> </SPAN>With this number, you
can now determine regulation specs for blow distance, key dip, letoff and
aftertouch.</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"> <o:p></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt">Let’s just say you want something
typical like a 3/8” key dip, 1/8” letoff, and .050” aftertouch.<SPAN
style="mso-spacerun: yes"> </SPAN>(Later I’ll show the equations for
solving for different variables)<SPAN style="mso-spacerun: yes">
</SPAN>Given the 3/8” key dip (.375”) and the .050” aftertouch, we subtract
aftertouch from key dip and know then that we have .325” of useable key dip to
move the hammer.<SPAN style="mso-spacerun: yes"> </SPAN>How far will it
move?<SPAN style="mso-spacerun: yes"> </SPAN>It will move 5xs the amount
of keydip.<SPAN style="mso-spacerun: yes"> </SPAN>5 x .325” = 1.625”.<SPAN
style="mso-spacerun: yes"> </SPAN>But that’s not the hammer blow distance,
because we haven’t accounted for letoff.<SPAN style="mso-spacerun: yes">
</SPAN>If we want 1/8” (.125”) letoff, we need to ADD that to the hammer travel
of 1.625”, so the blow distance is then 1.75”, or 1 ¾”.</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"> <o:p></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt">OK, let’s make that work out
algebraicly. </P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"> <o:p></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt">Key travel<SPAN
style="mso-spacerun: yes"> </SPAN>= Kt</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt">Hammer travel = Ht</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt">Action Ratio = Ar</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"> <o:p></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt">Blow Distance = Bd</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt">Key Dip = Kd</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt">Aftertouch = At</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt">Letoff = Lo</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"> <o:p></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt">Equation 1:<SPAN
style="mso-spacerun: yes"> </SPAN>Determine Action Ratio</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="mso-tab-count: 1">
</SPAN>Ht/Kt = Ar</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"> <o:p></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt">Equation 2: Determine Blow
Distance<SPAN style="mso-spacerun: yes"> </SPAN>(you pick key dip,
aftertouch and letoff specs, as in the above example)</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="mso-tab-count: 1">
</SPAN>Bd = [(Kd – At) x Ar] + Lo</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"> <o:p></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt">Equation 3:<SPAN
style="mso-spacerun: yes"> </SPAN>Determine Key Dip<SPAN
style="mso-spacerun: yes"> </SPAN>(you pick blow distance, aftertouch, and
letoff)</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="mso-tab-count: 1">
</SPAN>Step one: determine Hammer Travel<SPAN style="mso-spacerun: yes">
</SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt 0.5in; TEXT-INDENT: 0.5in">Bd – Lo
= Ht</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="mso-tab-count: 1">
</SPAN>Step two: determine Key Travel for that hammer travel</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt 0.5in; TEXT-INDENT: 0.5in">Ht/Ar =
Kt</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="mso-tab-count: 1">
</SPAN>Step three: add desired aftertouch to Key Travel to get Key Dip.</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="mso-tab-count: 1">
</SPAN><SPAN
style="mso-tab-count: 1">
</SPAN>Kt + At = Kd</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="mso-tab-count: 1">
</SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="mso-tab-count: 1"></SPAN> </P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="mso-tab-count: 1"><FONT face=Arial size=2></FONT></SPAN> </P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="mso-tab-count: 1"><FONT face=Arial size=2>OK, Lemme know whatcha
think!</FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="mso-tab-count: 1"><FONT face=Arial size=2></FONT></SPAN> </P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="mso-tab-count: 1"><FONT face=Arial size=2>John Dorr, RPT (<---
brand NEW RPT, but I love writing this!)</FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="mso-tab-count: 1"><FONT face=Arial size=2>Helena, MT</FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"> <o:p></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"> <o:p></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"> <o:p></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"> <o:p></o:p></P></DIV>
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