[Arm-netbook] microdesktop casework as DXF files for laser-cutting

[Tor, the Marqueteur]

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/
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