---------------------- multipart/alternative attachment In a message dated 11/10/03 7:17:11 AM, mfarrel2@tampabay.rr.com writes: >=20 >=20 >=20 > I've made myself a little pneumatic contraption for laminating ribs. I see= m=20 > to have just about everything worked out for proper function (actually, wo= rks=20 > quite a bit better than I had hoped!)=A0except for some excessive jig flex= . I=20 > have a=A01.5-inch-thick=A0Delignit pinblock incorporated into the jig for=20 > stiffness, but I still=A0seem to be getting several millimeters of flex in= the middle=20 > of the 5-foot long jig when I pressure up. So I think the solution is to p= ut=20 > a couple of=A0angle irons, or steel channels along the length of the jig.=20= This=20 > thing is getting VERY heavy, so I prefer to not use any more steel than=20 > needed. >=20 >=20 I've no science background, but i've made numerous structural steel jigs. My first jigs used steel as a monoblock material, a "one piece big enough to= =20 resist" approach. That is off target. What you want is a little teeny bridge structure. In=20 other words, multiple pieces of steel with lots of triangle shapes for rigid= ity.=20 This way there is not too much mass, but great rigidity. If you don't want t= his=20 large "fab" job, use a steel channel or even an "I" beam, but then it will b= e=20 heavy; I store my big jigs outside and paint them. A necessity after my firs= t=20 14 foot long soundboard jig. BTW don't order steel from your friendly=20 supplier, check the scrapyards for material. You can't pick and choose as mu= ch, but=20 it's way cheaper. You may consider this close to dumpster diving, but It is=20 invaluable to the machine builder. At the scrapyard you don't worry so much=20= about=20 the calculations, just buy way over what you need, and start an outside=20 storage rack area. If you start fab work like this, access a sawzall for cut= s, or a=20 torch. A resinod cutting disc in a tablesaw is a BAD idea. If you have=20 specifics shoot them back, happy to answer from no-training and 12 yrs. of p= ractical=20 experience. Glenn C. ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/5b/c7/6c/9c/attachment.htm ---------------------- multipart/alternative attachment--
This PTG archive page provided courtesy of Moy Piano Service, LLC