Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@g...> wrote:

Hi Stefan ( sorry about misspelling your name before -- must be brain
fade induced by the summer heat ),


 
> Just this minute i did a small experiment. I built the very simple
supply  
> shown in the link you gave for light edm work.
> Connected it up and used a manually moved pointy steel screw as
electrode.
> 
> i can definitely see that work is all i have to say. With this you
could  
> draw your PCBs by hand. Of course i got mighty rough edges with
moving the  
> electrode by hand, but i could mill slots in the copper with no
problems.

The higher pulse rate and lower current power supply yields a MUCH
smoother cut.

  
> I kind of feared it might mill away all copper around tiny residual
 
> particles, so that they remain there, but it seems it cleans the
copper  
> clear off in neat circles.
> I'm pretty much convinced it will work for me in a cnc setup.
> I can even see it useful as a "electric milling wand" to do touchup
work  
> or cutting sripboard or even manually cutting very simple boards. It
is  
> much faster and cleaner than scratching, as it doesn't affect the
epoxy.  
> The water is a drawback though.


In what way?  It keeps the elctrode from burning and washes out the
particles.  

> Very rewarding experiment, recommended for everyone.
> 
> (Here the URL again:  
> <http://cscott.net/Projects/FabClass/final/edesign1.html#schematic>
"A  
> simple circuit", stay under 30V if you want to touch the eletrode.).
> 
>
> I really need to see pictures. pleeeaaasssee ;-)
> 
>


I'll get right on it after the 4th.  Promise ;D


Curt