Date: Wed, 3 Sep 2014 15:27:32 +0000
From: Jack Rubin <j at ckrubin.us>
To: "Classic Computer List (cctalk at classiccmp.org)"
<cctalk at classiccmp.org>
Subject: Reproduction front panels and switch levers for PDP-8/E and M
Message-ID: <1409758047115.63856 at ckrubin.us>
Content-Type: text/plain; charset="iso-8859-1"
I'm in the process of reproducing front panels for PDP-8/E and/or M
machines, as well as switch levers for these machines and others that use
the same shape but different colors (e.g. 8/L, 11/20).
For the front panels, I'm working with a local (Chicago) silk-screen house
to create the reproductions. At this point (still exploring final
pricing), it looks like unit cost will be about $200 for a run of 5. This
will most likely be a CNC cut acrylic panel (laser probably won't work
because of the angled relief for the key switch) with silk-screen printing
front and back. The panel shape is the same for E and M but the screens
are quite different. I've also got a couple different M variations. Note
that each panel requires five or six screens, including black masking on
the back and transparent red or "frosted" masks for the indicator lights
in addition to the three colors on the front.
I'm not sure about possibly adding a transparent overlay (non-original)
over the front silk screening to protect the final product. Please let me
know your interest and thoughts about a protective overlay.
For the switch levers, "phooky" from the NYC Resistors has done a 3D
rendering -
http://www.thingiverse.com/thing:360853 - and printed
prototype levers and mounting frames. Note that there are three renderings
at the thingverse site - original lever, lever with improved pivot (metal
pin) and bracket for attaching lever to available slide switch. Phooky has
also printed up samples of these objects. The next step is to work on
injection molding the parts. The Resistors have an injection molding setup
and phooky is planning to create a mold using CNC equipment and his 3D
renderings. There are several reasons for moving from 3D printing to
injection molding for these parts. The first two, finish and mechanical
strength, are slowly being addressed by improved printers but the third
reason, color matching, is the critical difference.
The front panel project is in progress and hopefully panels will be
available in a few months.
The switch project is very much exploratory with no promises or dates at
this time.
Comments please!
Jack
I have heard that the reason for making the the pivot in plastic was that
this should brake instead of the switch itself or the PCB in case of an
accident.
I have however restored a couple in my 8/L that was broken by drilling a
hole through and inserted a metal pin. Works fine!
Although I find this very interesting, at least in the levers since they
fit on my 8/L.
/Anders