> > The benifit of mechanical etching is no chemicals.
> > the down side is the expensive cutters that wear out quickly.
>
> I have the impression that this is more of a problem with some
board materials
> than others, is that the case?
Yes, FR-4 is the most common and easiest to get. Seems no one knows
were to get boards as the question on here rarely gets an answer.
But the phenolic boards are much gentler on the cutters, but it does
not really matter if you can't get the darn things.
>
> > A dull cutter will raise a burr on the copper and dependong on
your
> > hold-down method, will or will not effect the rest of the board.
>
> I haven't yet begun to explore the possibilities of various
holddown methods.
> I can think of a few right off the top of my head, those being
simple
> clamps, some kind of a T-slot table (more clamps), or maybe a
vacuum
> holddown setup. What else is there?
Duct tape. No, really.
I have a pair of pins in the table the board slips over them for
alignment and from there the boards is held on the edges with duct
tape.
The drill does not lift the board and mechanical etching is held firm
with the two pins.
>
> > Another plus for the CNC is drilled holes.
>
> Yes, that's a big plus in my opinion. I'd ∗much∗ rather have the
machine do
> that than have to do it myself...
And THAT is why CNC-PCB_design was created !
the non-technical, home brew drilling concept you can build from
stuff laying around to spending $100.00-200.00 in parts.
Dave