kicad-developers team mailing list archive

[Cirilo Bernardo <cirilo_bernardo@xxxxxxxxx>]

----- Original Message -----

> From: Øyvind Aabling <Oyvind.Aabling@xxxxxxx>
> To: Andreas Beutling <andreas@xxxxxxxxxxxx>
> Cc: KiCad Developers <kicad-developers@xxxxxxxxxxxxxxxxxxx>
> Sent: Tuesday, February 5, 2013 2:20 AM
> Subject: Re: [Kicad-developers] HPGL
> 
[snip]
> 
> Hi Andreas.
> 
> Have I understood this correctly: You're using
> a pen plotter to print directly on the PCB ?
> 
> Is this the etch pattern or the silkscreen,
> and which type(s) of pen(s) are you using ?
> 
> I have a Roland DPX-3300 Drafting Plotter (ISO-A1/ANSI-D size !),
> so I tried some years ago to transfer the etch pattern using the plotter,
> but gave up, as I couldn't find any pens that worked reliably :-(
> 
> Either the ink wasn't etch (or even water) proof, the tip
> couldn't withstand the abrasive copper surface, or it was
> too wide, or the ink dried too quickly (causing clogging
> when crossing already drawn lines), or all of the above ...
> 
> One thing I _did_ get working though, was to coat the entire board with
> etch-resist ink, then scratch away the unwanted ink using the plotter.
> I used the sharp tip from a pair of compasses/dividers, mounted
> in a piece of "pen-shaped" aluminum (turned on a lathe).
> 
> Øyvind.
> 


When I did that sort of thing 15 years ago the pen I used was the type used for stencil work - it was a short steel tube (you can get various sizes) with a steel plug. I can't remember what ink I used now - it was a pretty thick ink meant for old drum recorders but it was also water resistant when dry.  I think I used a 0,8mm pen - too small and it clogs or you scrape off previously drawn parts of the track because the plotting is too slow, too big and you lose all the drill holes. It took a lot of experimentation way back then - a few inks, diluted or undiluted, etc. I just did all the tests by hand rather than with a plotter and when I had nice clean lines I tried it on the plotter.

 I can't even find these pens anymore since I can't remember the manufacturer, but I suspect some of the good quality drafting pens will also work - I prefer the short pens because you just put in a few drops of ink then wash them out afterwards.

- Cirilo