<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=iso-8859-1"><meta name=Generator content="Microsoft Word 14 (filtered medium)"><style></style></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1>Hi William:<o:p></o:p><o:p> </o:p>You are correct that boards don’t crown evenly, and this is particularly true of older boards which can often have that sine curve we have come to know and love. And these distortions can be great or small depending on the board and its condition. Yes, I have moved the gauge along the length of the rib and do get different readings. So if I am planning on taking more than one reading, I make a little dot mark on the panel where I want to take my measure again, and place the foot there the next time. <o:p></o:p><o:p> </o:p>I am comfortable with that limitation, because I believe that it still allows me to take the readings that I need with enough consistency to achieve meaningful accuracy as conditions change – such as loading and unloading boards. <o:p></o:p><o:p> </o:p>By the way, Jude has made the gauge of varying lengths. One of the difficulties of a longer gauge is positioning it to get it in place because it is rigid. <o:p></o:p><o:p> </o:p>That’s why I have been sawing off and removing all the beams. Makes things a hell of a lot easier. J<o:p></o:p><o:p> </o:p>Will<o:p></o:p><o:p> </o:p>From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On Behalf Of William Monroe Sent: Wednesday, June 22, 2011 9:56 PM To: pianotech@ptg.org Subject: Re: [pianotech] Soundboard Analysis<o:p></o:p><o:p> </o:p>Hi Will,<o:p></o:p><div><o:p> </o:p></div><div>One issue I have with the Crownulator is that boards do not necessarily (necessarily don't?) crown in a nice even radius.  Rather, they tend to be variably crowned.  I doubt that's news to you, so I'm posing this more as a question of whether or not you are comfortable with that limitation, and with working around it using Jude's gauge.  I'm sure you've probably taken readings at various placements along a particular rib  - what does that tell you?<o:p></o:p></div><div><o:p> </o:p></div><div>Thanks for the insight.<o:p></o:p></div><div><o:p> </o:p></div><div>William R. Monroe<o:p></o:p></div><div><o:p> </o:p></div><div>  <o:p></o:p><div>On Wed, Jun 22, 2011 at 7:17 PM, Encore Pianos <<a href="mailto:encorepianos@metrocast.net">encorepianos@metrocast.net</a>> wrote:<o:p></o:p><div><div>Hi David:<o:p></o:p> <o:p></o:p>I’m going to throw in my 1 ½ cents here for what it’s worth to you and others.  I do some things a little different than you do.<o:p></o:p> <o:p></o:p>Let me start by saying that I think there are better ways to measure crown than the method you describe.  I used to measure by way of the string method more or less as you do.  It’s slow, awkward, and probably not terribly precise.  <o:p></o:p> <o:p></o:p>About a year ago, I bought a Crownulator from Jude Reveley.  It is made up of a 1 ‘ long steel bar accurately flattened on one side.  In its center is a hole through which passes the moveable foot of a dial gauge.  You lay the bar square on the panel next to the rib.  As long as there is positive bearing, the dial gauge foot will move a distance that will be measured on the dial.  It’s a mirror image reading, so if the gauge is reading .080 (of a full circle of .100), this means that you have .020 of crown over that 1’ span.  There is a formula by which you can drop the numbers in and calculate the crown for the rib.<o:p></o:p> <o:p></o:p>I use it when putting in new boards too.  After the board is glued in and otherwise ready to go for stringing, I take a crown reading on as many ribs as I can get at and record those measurements.  When setting bearing, drive the board down and take crown readings til I get my target of 50% deflection.  Record those measures.  Then string and tune the piano, measure crown again and see how well I guessed in the process<o:p></o:p> <o:p></o:p>I think you would find the Crownulator significantly more accurate, quicker, and far easier to use.  <o:p></o:p>SNIP<o:p></o:p>Will Truitt<o:p></o:p> <o:p></o:p><o:p> </o:p></div></div></div></div></div></body></html>