<div>Oh, I thought the question at hand was whether the cutting of a groove into the bridge would cause a drop in pitch inbetween tunings. Let's see; with a 0.5mm drop of the string inbetween each tuning, the bridge cap would be cut in two in about 8 tunings. </div> <div>I agree with whoever suggested that the resistance of the board would lessen any impact of the groove on tension. </div> <div> </div> <div>Usually when things compact, they do so at a rate of 80% in the first 10% of the overall time frame so the groove lowering the pitch on a regular basis seems to me to be illogical. </div> <div> </div> <div>Keith<br><br> </div> <div><span class="gmail_quote">On 4/30/07, <b class="gmail_sendername">RicB</b> <<a href="mailto:ricb@pianostemmer.no">ricb@pianostemmer.no</a>> wrote:</span> <blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid"> <div bgcolor="#ffffff" text="#000000">Keith, you arent reading the posts close enough.  Sorry.. but John didnt say anything about retuning the piano back to frequency, then figureing tension.  The question at hand is how to calculate a change in frequency for a change in deflection. If you want to retune and calculate tension...then fine.  But thats another matter entirely. <br><br>Ric<br> <blockquote>><br>> No John<br>><br>> He does not just use Pythagoras' theorem just as you did.  And if you stop<br>> up and look closely I am sure you will understand this.  When you change the<br>> deflection you change three things... its length, tension, and frequency. <br>> The new length you can calculate just as you did.  But that leaves you with<br>> two unknowns... the new tension and the new frequency.<br>><br><br><br>No Rick,<br><br>the piano is retuned to the proper frequency after the recalulation of <br>length. Then you have a bunch of things that are not unknown anymore.<br><br>You really don't think a bunch of piano tooners are going to hammer a string<br>0.5mm down into the bridge and not tune the dang thing, do you? <br><br>Keith Roberts<br></blockquote> <div>-- <br><img src="cid:part1.07060501.07040306@pianostemmer.no" border="0"></div></div></blockquote></div><br>