---------------------- multipart/mixed attachment >I'm trying to apply some science to my soundboard rib making and I am >looking for "tables of static values for the Resisting Moment (W) and the >Moment of Inertia (I) for all the possible cross sections of sugarpine and >spruce (DIN 1052 Class I will suffice). Resisting moment for a rectangular cross section is half the height times bending stress in extreme fiber in pounds per square inch whatever that may be and for whatever reason you need it. MOI (I) for a rectangular cross section is 1/12*width*height^3. Used in various beam deflection formulas with the modulus of elasticity for whatever material you're using, to calculate deflection under load. E for spruce=1570000, sugar pine=1200000 >What is the formula for converting pounds/inch squared to kg/cm squared? lb/in^2 *0.0703067=kg/cm^2 >Given a right angle connected to the outside of an arc of a circle, how do >you prove the circle is 60'? (I made a jig for crowning ribs that is >adjustable and I want to calibrate it. radius=(4*crownheight^2+riblength^2)/(8*crownheight) I think that's got it. Ron N ---------------------- multipart/mixed attachment --- Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.545 / Virus Database: 339 - Release Date: 11/27/2003 ---------------------- multipart/mixed attachment--
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