[Arm-netbook] video of laptop casework demo available

[Luke Kenneth Casson Leighton]

On Mon, May 4, 2015 at 6:00 PM, Luke Kenneth Casson Leighton
<lkcl at lkcl.net> wrote:

>> I imagine that this would be adapted to more scalable processes once
>> prototyped, however, which would infuriatingly eliminate some of the precision
>> issues experienced during prototyping. Or would you first go through an
>> iteration or two of higher-specification 3D printing first?
>
>  right.  ok, the plan is as follows:
>
>  * phase 1: get 3d printed parts working (as +ves)
>  * phase 2: split all parts into two -ves
>  * each 1/2 part will be subtracted from a "block"
>  * this "block" will fit inside a metal container
>  * the two 1/2 -ve parts will be fitted inside the metal container
>  * low-viscosity injection mold plastic will be used to create a prototype part

 so *right from the start* i have to design each part so that it can
*either* be 3d-printed (as a +ve part) or that it can be split into
two -ve halves.

 these two halves will fit together, creating an inner space that can
be filled with molten plastic... *but*, the tricky part is that it has
to be possible to remove the two halves without destroying the plastic
inside it.

 so, having an inner space that goes round a corner is not possible to
do, because at least one of the halves of the mold will be stuck.  the
two halves have to come out of the plastic *straight* - no overhangs
are allowed.

i don't entirely know if this is ok, but i am counting on it being
possible to pull one of the mold halves out at one end first, followed
by the other.  the reason is because i have some screw-holes and
insets which i am *hoping* will not be destroyed or damaged when one
half of the mold is pulled away from the plastic.

... we shall have to see!

l.