Forgot the link to the calculator for changing wood dimensions in changing climates:
http://owic.oregonstate.edu/wood-shrinkswell-estimator Tor On 21/03/17 17:56, Tor, the Marqueteur wrote: > On 21/03/17 17:07, Normand Chamberland wrote: > ...snip... >> On the manufacturing side, I wonder if it may be a good idea to check the >> real thickness of the 3mm plywood boards. Due to manufacturing >> tolerances, materials provided in sheets are often thinner than their >> nominal thickness be it for plywood, plastics etc. > > Good point. Also, with plywood, the thickness /will/ change in different > climates. Length and width should stay pretty stable, enough that I > wouldn't consider worrying about anything other than perhaps two spaced > solder joints directly being pushed/pulled by the case. > > Taking quartersawn Birch (approximately correct for rotary cut hardwood > plywood, going from an air conditioned desert conditions (70F, 10%RH) to > an open tropical environment (80F, 90%RH), one could expect the case to > swell .06" (or about 1/16") per inch of thickness. > >> >> As for the screws, difficult to evaluate from a couple of pictures but >> they seem to be M3 socket head, black oxide, with hex nuts at the bottom >> (possibly 2 per screw) with some kind of either plastic or vinyl cap. >> Nickel plated screws would be better IMHO (considering the hex nuts are >> either nickel or zinc) and not prone to rust like black oxyde screws, but >> they might be difficult to source and more expensive. > > IME, (US based) zinc plate is usually easy to come by and fairly cheap. > The nice HW that really won't rust and is expensive is SS. > > Tor > >> >> Cheers, >> >> Normand >> > -- Tor Chantara http://www.fineartmarquetry.com/ GPG Key: 2BE1 426E 34EA D253 D583 9DE4 B866 0375 134B 48FB *Be wary of unsigned emails* Stop spying: http://www.resetthenet.org/
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