Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, David McNab <david@r...> wrote:
> Hi,
> 
> After successfully getting my CNC rig working for PCB drilling runs
> (updated info/photos at http://www.freenet.org.nz/cnc), I tried using
> the rig to draw etch-resist artwork directly onto the copper surface.
> 
> Following recommendations on other websites, I'm using a Staedtler
> Lumocolor 313 superfine red pen, which is wonderfully etch-resistant,
> dissolves quickly with acetone, writes finer and is more easily
> available and 1/3 the price of 'dedicated etch-resist pens' from
> electronics shops.
> 
> However, the result was not good. Even the 'superfine' variant of this
> pen writes a 0.7-0.9mm line, way too thick for my layouts. Also, with
> the relatively slow speed of my CNC transport, the pen tends to bleed
> out to a thicker line.
> 
> I notice from some pcb sites that some people rip the guts from the pen
> and insert the ink-bearing felt into a plotter pen. That might be an
> option, but such pens might be hard to get given that plotters are no
> longer in vogue.
> 
> I've thought of mutilating a Staedtler 0.1mm black felt-tip pen, pulling
> out the black felt tank, running the pen dry, then inserting the red
> lumocolor in its place. But I thought I'd ask here before destroying
> $7-$10 worth of pens.
> 
> Are there any simple ways to get this pen to deliver a thin (<0.4mm)
> line? Or should I stick to the thermal toner transfer which I've already
> got working?
> 
> -- 
> Cheers
> David


David< I have pulled apart the pens you have listed and squashed the
ink out using a pair of pliers.
I have used a staedtler pen and modified holder to suit a Roland pen
plotter, the pen tip is very small I can't remember the pen number off
the top of my head but I will find it if you need it. The pens are
still available in Australia so should be all right everywhere else.
Philip