19 Jan
2019
19 Jan
'19
5:52 a.m.
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!