Re: [CAD_CAM_EDM_DRO] Laser "route" Printed Circuit Boards

Danny Miller wrote:

> But a raster is probably gonna be really, really slow.
>

If you used steppers, and went Zig, stop, zag, then back again, yes.
But, a spinning drum can process a lot of pixels quickly. I have a
raster laser
photoplotter I built about 14 years ago. The drum spins at 600 RPM, and it
exposes 1000 dots/inch and 1000 raster lines/inch. So, it lays down
0.6" per
minute of pattern, up to the full circumference of the drum, which handles
up to 20". Since the drum never slows down until you are done, you only
lose
the time to come around and start the next line. The carriage steps
over during
that time.

So, even at one MILLION pixels per square inch, it can lay down a 6" square
picture in 10 minutes, no matter how complex. I use this machine to write
photomasters for PCB etching, solder stencils and panel labels. Now,
the pixels are
5 us long under the laser, so you'd probably have to slow down a bit to
actually
burn copper foil off a substrate. But, I bet with the 3 mil wire that
Roger spoke of
using, such a machine (maybe with a smaller drum) might not be much slower.

Jon