---------------------- multipart/alternative attachment In a message dated 2/18/2006 9:26:00 A.M. Pacific Standard Time, rnossaman@cox.net writes: Dale wrote > Ok Now I,lm confused. If were only trying to support only 400 to 600 > lbs. of down bearing force as Del inferred recently or whatever one > calculates this to be, then what's all the fuss about. My loading of new boards these days is typically half again over 600 lbs. Ron, so you are saying a 900 lb bearing load is probably an in the ball park average plus or minus for various sizes of pianos & string scale tensions. Then my comment a couple weeks ago about bearing being 1000 lbs or more depending on who you ask wasn't that far off this figure even though Del disagreed with that as being "excessive." >It's not that > much of a load. I've never seen ribs sheer, break or explode under > bearing. I've seen compression crowned boards with fat crown & > bearing after 40 , 50 , 60 years or more that sounded wonderful & the > ribs still intact & of course others that didn't. Ron Wrote------- No, the ribs don't usually explode, but I have seen broken ribs in the high end two or three times. In this part of the country, it's rare to find old compression crowned boards with decent crown and bearing. Dale wrote---In our area we see it fairly commonly up to about as old as 60 years. But these survived in the bay or on the coast where temperate climates are the rule. The ribs do other things in these boards like straighten out when the > crown deflates but a stiff spruce crowned rib with nice tight straight > grain & a laminated rib in my mind will do just about the same thing for > as long as we want them to if designed to handle the appropriate loads. > And they will do it for a tremendously long time reliably. I like the > whole laminated rib thing & all & there pretty in a techno sense too but > I'm just throwing out the question is it overkill? > Flame suit on & feelin onry today > Dale Could be. Laminating costs me time to glue them up, but saves me time to cut them out. It uses spruce with grain angles and color defects that would otherwise not be usable in belly work, so it's good conservation of materials. I like that part a lot, but then I'm still laminating bridges from salvaged maple racquetball court flooring. All that appeals to me as well. Hey maple is maple. I'm still making bridge caps from an upright that was made from solid beautiful maple ...every last piece In fact, at the cost of a little extra time, I can build up ribs over two or three clamping's, that use up the shorter cutoffs that would otherwise be trash, on the rib bottoms where the feathering would cut away and waste good wood anyway. See photo. I also found it bothersome to bend, clamp, and try to rip ribs to depth accurately with solid ribs, especially the tighter radii in the treble. With laminated, it's simple, accurate, and more easily controllable. I admit it's tough to curve a 12 inch rib to a 20 ft. radius & have thought about doing it differently As far as performance goes once they're in the piano, I doubt there's much difference. Zzzzaaactly what I'm thinking. Nice picture. Says a lot Dale Ron N ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/c4/90/a3/57/attachment.htm ---------------------- multipart/alternative attachment--
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