KIM Uno /PiDP-11 plans...

Mike Ross tmfdmike at
Fri Oct 23 04:40:28 CDT 2015

On Fri, Oct 23, 2015 at 10:26 PM, Alexandre Souza
<alexandre.tabajara at> wrote:
>>> But a 11/70 replica needs two physical 'cosmetic elements': proper
>>> switches, and the white bezel/frame. The switches *seem* to be feasible to
>>> produce cheaply (I will know in a month with PDP-8/I switches...). The white
>>> bezel though brings me into unknown territory. 3D CAD (based on Museum
>>> Measurements), then injection molding or vacuum forming. Or any technique to
>>> produce a plastic object in medium quantities. All I know so far is that
>>> it's very feasible - and much cheaper to do than just a few years ago.
>    Jumping on the metro (since I'm so young) running:
>    Can't it be 3D printed? Or done with vacuum forming? Resin molding?
>    Are you talking the white bezel on this photo?
>    It can be done easily:
>    - You can do it in a 3D prusa-something printer, if you divide it in
> printable blocks, and glue it afterwards.
>    - You can easily do that in Vacuum Forming. Since I never saw a 11/70 in
> front of me, I don't know the size/hardness requeirements, but I believe it
> is feasible
>    - You can create a cast mold in some material and use liquid resin (epoxy
> comes to mind since it doesn't shrink/expand on cure). Probably it would
> need a two-part positive/negative mold. Easily done if I had the original
> part on hand
>    - I haven't seen all the details, but I believe it can be 3D-cut into a
> suitable CNC machine, in wood or plastic.

Actually, thinking about it, there are two approaches, and they're both valid:

1. Take a lot of trouble, spend a lot of money, and produce as close a
replica of the original as possible.
2. Do what he did with the PiDP-8/I; something 'close enough' which is
reasonably accurate and evokes the original very nicely, but doesn't
even pretend to be a precise replica.

I don't think it even *needs* a bezel IF option 2. is selected. Print
a different perspex, add a few more switches, paint them purple
instead of brown, add a couple of rotary switches... put it in a
wooden box again. Job done very simply.

But whether it's 1. or 2. I don't see any strong argument for NOT
making it full-size. But we can all talk about it; he's the poor
bugger who actually has to do the work :-)
'No greater love hath a man than he lay down his life for his brother.
Not for millions, not for glory, not for fame.
For one person, in the dark, where no one will ever know or see.'

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