They do? The change in distance from the struts to the bridge when I let off tension corresponded pretty well with the change in downbearing. In other words, the soundboard moved up, the plate didn’t. David Love www.davidlovepianos.com From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of Encore Pianos Sent: Thursday, June 23, 2011 3:06 PM To: pianotech at ptg.org Subject: Re: [pianotech] Soundboard Analysis Now, that’s an explanation further worth exploring. The plate struts certainly rise when tension is added. Some struts have nose bolts to restrain that upward movement, others don’t. Next time you teardown a piano David, measure that upward or downward movement at the same time you are taking your bearing and crown readings. I think it is a better explaination than the one I offered. Will Truitt From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of Albert Picknell Sent: Thursday, June 23, 2011 5:21 PM To: pianotech at ptg.org Subject: Re: [pianotech] Soundboard Analysis --- On Thu, 6/23/11, David Love <davidlovepianos at comcast.net> wrote: When I took pressure off the board by letting down the tension and saw an increase in bearing (soundboard rise) and a change in the distance between the bridge and the struts (which I didn’t include below), and then crawled under to check the crown it was still not positive. *************** The plate drops when you let off tension. Because the string plane is below the plate struts, the struts rise when you put tension on the strings, and drop when you release that tension. It's like stringing/destringing a bow. This would at least partially account for the increase in bearing, as well as the decrease in the distance between the bridge and the plate struts. Cheers, Bert -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://www.moypiano.com/ptg/pianotech.php/attachments/20110623/bc269a65/attachment.htm>
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