Homebrew PCBs

Here is a board I did four weeks back. Three UniPolar choppers
using a L297-Tip120s and some logic diodes. Circuit worked but it was
to noisy.  

http://crankorgan.com/Kchop.JPG



--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@g...> wrote:
>
> If it were efficient, why isn't the industry using it?
> It takes ages compared to etching.
> 
> About laser milling, yes, it's done these days. check with google.
they  
> see the reflection change when the copper is gone i think.
> Would be fantastic to have such a machine, but if i could afford one
i'd  
> have people doing PCBs for me not the other way around.
> I suspect EDM is the closest we could get for a while, but i have no
time  
> at all to look into that this year.
> (About the drivers, i'll finish a job this weekend and then i'm all
yours,  
> thanks)
> 
> ST
> 
> 
> On Fri, 09 Dec 2005 00:05:22 +0100, lcdpublishing  
> <lcdpublishing@y...> wrote:
> 
> > I just thought of something else regarding efficiency. Even though I
> >
> > don't make a lot of circuit boards, I have been etching two, and
> >
> > even, three boards at the same time.  This is very efficient and is
> >
> > only limitted by the size of the etching tank.
> >
> >
> > Having been in shops of one type or another my entire adult life, I
> >
> > probably have been exposed to more toxins than I care to think
> >
> > about. So, fear of: acids, projectiles, and dust isn't an issue for
> >
> > me - been there done that sort of thing I guess.  Frankly, I am much
> >
> > more fearful of the dumb girl in the car in front of me talking on
> >
> > the cell phone and not paying attention to driving ;-(
> >
> >
> > A while ago I did read that article you mentioned, and you are
> >
> > right, they were not very positive at all about milling.
> >
> >
> > Hmmm, makes me think of another possiblity though - laser etching?
> >
> > I know there are lasers that can focus their "cutting depth" which
> >
> > might allow for cutting through the copper and not the substrate.  I
> >
> > would have to guess that this sort of laser would require a bit of
> >
> > power though.
> >
> >
> > Chris
> >
>