Homebrew PCBs

Hi Stefan,

Then I will add that scratching method is not worth anybody's time 
unless they are imprisoned. Mike

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
> On Thu, 27 Jan 2005 15:07:12 -0000, onenastyviper  
> <oneNastyViper@h...> wrote:
> 
> >
> > Hi, I have recently rescued a HP 7475A plotter and I am looking at
> > converting it to handle pcb scratch etching (I think the 
mechanism is
> > nowhere near strong for milling).
> > My question is do any members have any good links or files on 
scratch
> > etching?
> > I am thinking either direct copper-scratching (styluses??) or
> > scratching though an etch-resist and etching the board as normal.
> > Has anybody tried this?
> > What type of results did they get on track resolution??
> > regards, PK
> 
> 
> track resolution with a OHP pen (staedtler) was bad, here.
> couldn't even get a trace between DIL pins, and the width is 
inconsistent  
> because it depends on how fast the pen moves.
> 
> I never tried scratching a resist, but my suspicions are that it 
has  
> similar drawbacks as milling in terms of speed and result.
> 
> As for tt we takled about, i think a old printer at ebay is cheap 
enough  
> not to bother with the plotter method.
> I'm not one of the usual nay sayers (hi mike ;-) ) but i have tried 
it and  
> have had bad results. Problems seemed unresolveable so i abandoned 
the  
> method.
> Now the weakest link on bbc is about to begin, so i'll leave it at 
that.
> 
> ST