<HTML>In a message dated 12/7/2002 5:58:15 AM Pacific Standard Time, sec@overspianos.com.au writes: <BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">Subj: Re: Rib grain orientation Date: 12/7/2002 5:58:15 AM Pacific Standard Time From: <A HREF="mailto:sec@overspianos.com.au">sec@overspianos.com.au</A> Reply-to: <A HREF="mailto:pianotech@ptg.org">pianotech@ptg.org</A> To: <A HREF="mailto:pianotech@ptg.org">pianotech@ptg.org</A> Sent from the Internet          Ron</BLOCKQUOTE>                 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. The material is stiff and predisposed to this orientation already. It sounds like a good match ehh? I used some already. No worrys.      If there was a slight stiffness difference it could be made up in rib thickness. 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). I doubt  if it requieres a different calculation.   Why would it be benificial to change the grain orientation to have the ray run the other way.I don't follow this.     Regards           Dale <BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px"> Hi all, I have been wondering about the merit (one which seems to be a long standing tradition) in orienting the rib grain such that the growth rings run vertically, to set the medullary rays parallel to the sound board panel. Now I can understand the logic behind this with the CC guys, since they are likely to achieve a higher crown when the panel re-hydrates. However, in the case of rib crowned construction, wouldn't it be advantageous to set the grain in the rib such that the growth rings are horizontal and the medullary rays perpendicular to the sound board panel? I am contemplating setting the rib grain this way for piano no. 004 (both 004 and 005 are now sold before completion, which is quite a relief). Dale, Del and Ron N., and any others who may be using RC construction. What are your thoughts on this matter? By the way, we decided to build the cut-off as a laminated curve (I can't remember if I've mentioned this previously on the list, since I had originally planned to make it from scarfed material). We increased the cut-off rail section size to 50 mm wide by 35 mm deep, using 17 laminates of 2.9 mm thickness. I will try bending it with 4 mm laminates for piano 006. When cutting and drum sanding the laminates at 3 mm it is quite wasteful of wood. I'll get some photos of the buck and cut-off scanned and onto the website soon. Ron O. -- </BLOCKQUOTE> </HTML>