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

[Tor, the Marqueteur]

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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