The weekend before last, I picked up a Gould 5010 electrostatic printer/plotter along with
some PDP8 gear.
The technology is interesting. It writes an electrostatic charge directly on the paper,
and develops with a liquid toner "fountain" as the paper exits the machine.
Mechanically, it's quite simple, with just a single stepper motor to advance the paper
and a pump to recirculate the toner. According to some patents I found on the web which
appear to match the configuration of the write head, the pins are activated by a clever
coincident-current addressing scheme that avoids the need to dedicate a driver to each
pin.
The product line was eventually bought by Calcomp, which continued to manufacture
electrostatic plotters into the 90's. A successor company still provides paper and
toner for some models, but the 5010 is not mentioned on the website, and I have no idea
whether supplies made for the newer models will work in the 5010.
The printer looks reasonably good on the outside. Internally, there are a few rusted
places that could use cleaning and repainting, but it doesn't look like it's
structurally or functionally compromised in that respect. The vinyl tubing for the toner
circulation, on the other hand, has turned brittle and most of it is missing, and it looks
like there has been some toner leakage/spillage at some time in the past. Most
distressingly, the electrostatic write head is gunked up and/or corroded, and I suspect it
is no good. The printer is a free-standing unit, but not particularly heavy. Two guys
lifted it into the back of a minivan without difficulty.
Before I strip this thing for parts (it has a couple of nice power supplies, among
others), is there any interest in it? Does anyone else have such a printer and need
parts?
--Bill