How to refurbish plotter pens?

[emanuel stiebler]

On 2019-01-19 04:57, Mattis Lind via cctalk wrote:

> So I concluded that the best option is to make a new pen holder plunger
> which could take standard ball point refill. The Pilot  BRFV-10M seemed to
> be very common refill and would probably work well if I had another pen
> holder. I asked around and found a guy with a lathe that made one for me.
> Unfortunately it wasn't working immediately. I hadn't thought of certain
> mechanical properties of the mechanism.

I did something like that 20 years ago for my HP plotters. Back then, I
found some ball points, which had a pressurized cartridge, so you could
draw pretty quick lines ;-)

Yes, I did it with an aluminum holder, today, I would probably ask
somebody to 3d print some plastic piece, to reduce the weight of the
moving part

> Then I had a problem that the pen stayed in the up position. Most likely
> held by some kind of remaining magnetism that could withstand the force of
> the spring. A couple of M3 washers was used to reduce the contact area
> between the pen holder plunger and the top lid which made it work.
> 
> http://i.imgur.com/PRGUa9U.jpg

You're not planing on getting this through TSA?
;-)

> And in action:
> 
> https://i.makeagif.com/save/QCDG_W


Pretty COOL !!!

> controlled by a quick and dirty PDP-11 program :
> https://github.com/MattisLind/pdp11-plot

One day I have to set up gcc for my pdp11 ...

Cheers!