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

[Luke Kenneth Casson Leighton]

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crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68


On Wed, Mar 29, 2017 at 11:34 PM, Mark Van den Borre <mark at lusis.eu> wrote:
> Hello Luke, list,
>
> This is work by Normand, FreeCAD expert and kickstarter backer:
>
> http://glasno.st/microdesktop_model2_normandc3.fcstd
> http://glasno.st/microdesktop_layers_v1.dxf

 ha!  cool!  looks really good.  i love the curves on the corners and
the edges, if that shape can be retained i think it'll look absolutely
stunning.  also i notice you filled the gap over the top of the
VGA-DCjack which i missed that possibility, well spotted.

 ok, so you recall, i mentioned that it's quite tricky, more than i
had imagined it would be?  the arrangement you've made, norman:

 * the PCB will fall out of the casework (both ways, forwards and backwards).
 * it will also lift upwards by about... 1mm, rattling around.
 * the middle layers also need to be split into separate halves.
right now, the components are in the way.
 * the layer below the PCB (with a cutout for the micro-sd card) will
be in direct contact with the PCB, preventing heat dissipation
 * also you notice the cut-away in the corner of the PCB underneath
the eject button for the PCMCIA holder? the idea there is to put a
small recess (which we have to think how not to interfere with the
aesthetics) that will make it easier to eject.
 * layers 5 and 6 really should be hollow, so that there's a chance
for air to circulate

 also, a decision needs to be made whether to line up layer 2's "high
edge" with the top of the PCB or whether to line it up with the
*bottom* of the PCB, ass you've done.  the way i've tried it, you end
up with one less piece of plywood.  but the way i've tried it, layer 2
will need to be 4mm thick.  i'm still leaning towards that

 one other consideration, should there be ventilation holes drilled in
the top and bottom, for air circulation?  people might wish to
overclock these things and there should be room for them to put an
ultra-slim fan inside, as well as electronics (access to the 20-pin
header).

 on the crude technique i'm using, images microdesktop_1.png and
microdesktop_2.png are here:
 http://hands.com/~lkcl/eoma/tablet/3dcase

 also the 9-or-so DXF files which are crudely put together with
pyopenscad are also there.

l.