Homebrew PCBs

> Using 1 oz. copper board I can burn a 1 mil dot with one pulse and
> finish an entire 8 x 11 inch board in under 45 minutes.
>

I see.

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.  
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.
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.).



>
>
> At this moment I'm just happy to have the basic setup working and
> producing boards!  There will be time enough for refinement after I
> get it debugged.

I really need to see pictures. pleeeaaasssee ;-)


>
>
> I agree but right now I want to "crawl before I walk"  Right now I'm
> working storing the results of a 1000 dot per inch black and white
> scan in the controller.
>

Yea that are only small details, the mechanic/electric setup works, and  
that is great.
How the software is done is a minor point. Of course milling isolation  
paths directly would be faster than raster but time isn't really an issue  
at the moment.
Also, the software is easily tinkered with later on.

> I was thinking of using a tapered tube with needle in it's center to
> dispense solder paste ( or One Shot Sign Painters enamel? ) in
> controllable amounts.  Maybe later ;D
>

I thought about a paste syringe with pneumatic dispenser. But later is the  
right word.

ST