<!doctype html public "-//W3C//DTD W3 HTML//EN"> <html><head><style type="text/css"></style><title>Re: Rib grain orientation</title></head><body> <div>At 11:52 PM -0500 7/12/02, Erwinspiano@aol.com wrote:</div> <div><br></div> <blockquote type="cite" cite><font face="Times New Roman" color="#000000" >           <span ></span>     Honestly I wonder if it matters. I cut up some tight grain& dense old sugar pine stock from material gutted from a old pipe organ. Some of the pieces took on a beautiful tight arc appropriate for some tight radius treble ribs.</font></blockquote> <div><br></div> <div>Sure, but I was wondering if we shouldn't be choosing to cut it with the rays vertical, if there is a choice, to gain the benefit of the slightly higher modulus of elasticity along the line of the ray.</div> <div><br></div> <blockquote type="cite" cite><font face="Times New Roman" color="#000000">     If there was a slight stiffness difference it could be made up in rib thickness.</font></blockquote> <div><br></div> <div>True, but ideally aren't we trying to achieve the highest panel stiffness with the least weight?</div> <div><br></div> <blockquote type="cite" cite><font face="Times New Roman" color="#000000">No big deal. Ask some one in our engineering dept. if the wood strength formulas change for this slight change in orientation. (that would be you).</font></blockquote> <div><br></div> <div>Ron N's post confirmed that there is a minor though measurable improvement in strength along the line of the ray.</div> <div><br></div> <blockquote type="cite" cite><font face="Times New Roman" color="#000000">. . Why would it be benificial to change the grain orientation to have the ray run the other way.I don't follow this.</font></blockquote> <div><br> <br> </div> <div>I put forward the question since I have a large slab of Sitka from which I will be cutting out the rib stock for piano 4. The board is of such a size that I have a choice of grain orientation. The question was intended to see if any others might be sharing my views on this matter.</div> <div><br></div> <div>I agree its a very small point, but sometimes its the minutiae we concern ourselves with. Following on from Ron N's post where he discussed the orientation of the rays in hammer shanks, he was saying that most makers don't seem to regard it as important. Indeed, I have tested hammer shanks for stiffness with and perpendicular to the ray and its only just measurable using a dial guage.</div> <div><br></div> <div>Ron O.</div> <x-sigsep><pre>-- </pre></x-sigsep> <div>_______________________<br> <br> OVERS PIANOS - SYDNEY<br> Grand Piano Manufacturers</div> <div><br></div> <div>Web: http://overspianos.com.au</div> <div>mailto:info@overspianos.com.au</div> <div>_______________________</div> </body> </html>