Homebrew PCBs

Hi John,

I hadn't got the feed down to a calculation like that!  I just made some
shorts cuts at slow speed to see what they'd look like.  My first board
attempts will be with a Dremel!  Later, I'll possibly get an air-driven
tool, if warranted.  My PCB mill project is based on stuff I've
collected from surplus.  Some ways w/ zero-backlash (I think)
leadscrews, some small steppers, some drivers (either MaxNC's board, or
a set like Gecko's).  I just need the time to get it together (and the
design keeps on getting upgraded as I find new deals in surplus)!

Alan  KM6VV


crankorgan wrote:
> 
> Alan,
>      Mechanical Etching bits can only move  .0004 to .0006" per
> revolution of the spindle. This limits the machines that can make
> circuit boards. I always get a laugh when I see an adapter to hold
> a Dremel in a Bridgeport. A ton of power but not enough speed to
> engrave or mill circuit boards. PCBMills run 15,000 to 30,000 rpms.
>      If you search the internet you will see a few test boards that
> are milled. I have only seen a few real boards that are milled. There
> is alot of talk about using dental bits. I use a bit that was
> designed for milling circuit boards. The best you can hope for is 800
> inches of copper per bit. People ask me about milling 12" by 12"
> boards all the time. Good luck with that idea. Even a few traces on
> a 12" by 12" board will add up to 800 inches very quickly. A 12"
> trace is really 24" long.
> 
>                                         John