<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:x="urn:schemas-microsoft-com:office:excel" 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=us-ascii"><meta name=Generator content="Microsoft Word 12 (filtered medium)"><style></style></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1>I’ll have to look at the tool.  It sounds interesting and useful.  I haven’t found the string method to be particularly difficult or inaccurate, at least for my purposes.  I can get a reading easily to the .25 mm with a simple graduated wedge gauge and combined with bearing readings above a change in the crown can be calculated and then verified as the tension either increases or decreases.  <o:p></o:p><o:p> </o:p>The exact amount of crown that exists on new boards once I’ve made them is not really something I worry too much about.  I’ll check it, but if it’s a little different than I anticipated that’s not really a big concern.  There’s always some variation from what was anticipated and what is actually delivered.  When stringing the piano I rely pretty much solely on downbearing measurements to track what’s happening to the board as I’m more concerned with how it’s loaded than how the exact amount of crown I have.   I do track the loading pretty carefully topside with a  Lowell Gauge.  <o:p></o:p><o:p> </o:p>The purpose of my posting those numbers was for those who don’t necessarily take these kinds of measurements or try and calculate how an old board might react in order to determine whether the board is useable or not.  Not everyone does, I find.  You clearly do and your method with this tool is certainly fine.  I’ve found the string method works quite well and haven’t found it burdensome.  As Ron mentioned, it can tell you things that the gauge can’t as easily or quickly, like the overall shape.  On old boards I use the amount of crown combined with downbearing measurements during teardown to determine if I will be able to load the board adequately and where it is that I might be concerned with overloading the board and pushing it through positive crown.  On old boards I don’t have a problem with squashing them flat or close to it but I don’t want to go beyond.  With crown and downbearing readings during teardown you can determine if you enough crown to adequately load the board.  If you need 700 lbs under normal circumstances but can only load the board with 250 lbs before pushing things past flat then you have a problem.  If the cushion I have there has to be measured in thousandths of an inch then I’m probably changing the board.  This is a fairly simple method to make that determination and doesn’t require any fancy gauges.  Still, I might contact Jude and buy one if he’s offering them.  I’m always interested in new devices.  <o:p></o:p><o:p> </o:p>BTW make sure are aware of humidity levels before you take measurements.  We didn’t mention that but you’ll certainly get different results at 70% as compared with 30%.  <o:p></o:p><o:p> </o:p><div>David Love<o:p></o:p>www.davidlovepianos.com<o:p></o:p></div><o:p> </o:p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On Behalf Of Encore Pianos Sent: Thursday, June 23, 2011 2:52 AM To: pianotech@ptg.org Subject: Re: [pianotech] Soundboard Analysis<o:p></o:p></div></div><o:p> </o:p>Hi David:  <o:p></o:p><o:p> </o:p>If you reread my post you will see that all the readings are taken with the board glued in and at the various stages of the process working up to and including stringing, tuning, and loading the board.  I can throw the  gauge on the panel when it is ribbed and out to be worked on, but I don’t think that is of as much value as the in piano readings.<o:p></o:p><o:p> </o:p>I do use it to analyze boards prior to teardown.  Certainly when I am doing an estimate I take it with me and can take readings on every rib I can get to, along with bearing readings on the topside.  And once the piano is in the shop, do all this as part of the teardown process, particularly if I am going to be using the old board again.  <o:p></o:p><o:p> </o:p>You are correct that in some places the access will be more difficult or impossible, particularly in the high treble where things get much more  crowded.  The beams can be in the way in other places.  Sometimes I shift the location to one side or the other to avoid the beam, but generally try to center it under the treble bridge.  You may have better access with your string in the problem areas.  Otherwise, it is no more difficult than laying on the floor, reaching up with gauge in hand and setting it next to the rib, and taking a reading with sufficient light.  That takes only a few seconds to do.  In those places it is easier and faster.<o:p></o:p><o:p> </o:p>As I said earlier, it will not measure negative crown, but neither does the string.  A straight edge won’t give you a measure, but will tell you that it is negative.<o:p></o:p><o:p> </o:p>Will<o:p></o:p><o:p> </o:p><o:p> </o:p></div></body></html>