Homebrew PCBs

----- Original Message ----- 
From: "joshdewinter" <joshdewinter@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, January 07, 2004 9:54 PM
Subject: [Homebrew_PCBs] Xerox printers?


>
> > I worked for Rank-Xerox UK many years ago.
> >
> > Xerox's first copier was a manually operated 'flat bed' copier,
> with a
> > photoreceptor plate. The plate
> > was charged, then exposed to the image. The image on the plate was
> then
> > developed
> > by cascading developer and toner over it, the toner image on the
> plate was
> > then transferred
> > onto paper and passed through a fuser (a simple radiant heater).
> >
> > Even when automatic copiers like the 914 and 813 were developed
> the flat bed
> > machines were still popular for certain jobs, like making
> prototype PCBs.
> > Instead of transferring the toner image onto paper, the image on
> the plate
> > was transferred directly to the copper surface of a PCB. It was
> then passed
> > through the fuser and then etched. I saw some PCBs made using this
> technique
> > and they were quite good by the standards at the time. I kept
> meaning to try
> > it for myself, but never got round to it.
> >
> > Leon
> > --
> > Leon Heller, G1HSM
> > Email: aqzf13@d...
> > My low-cost Philips LPC210x ARM development system:
> > http://www.geocities.com/leon_heller/lpc2104.html
>
> Hi Leon.
>   This fascinates me.  I too tried to run a PCB straight through the
> office laser printer (yes, trying to get them to buy a new one)... I
> found that the toner didn't stick to the copper...of course, no
> charge would mean the toner particles wouldn't cling to it.
>
> So are these older Xerox copiers still available?  Do they require a
> bunch of now hard to find supplies to operate?

It was about 35 years ago when I last saw any of these machines, so I doubt
if any are still around. The case was made of wood! I suppose you could make
your own from scratch, like Chester Carlson (the inventor of the Xerographic
process) did. The tricky thing is the selenium-coated plate, everything else
is standard optics and electrical stuff. If you look at Carlson's original
patents, you will see exactly how they worked. I think he used a rabbit fur
brush to remove the excess toner from the plate. The developer was 'Ottawa
sand' (uniform particle size) coated in a special resin that held a static
charge.

Leon
--
Leon Heller, G1HSM
Email: aqzf13@...
My low-cost Philips LPC210x ARM development system:
http://www.geocities.com/leon_heller/lpc2104.html