Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

Alan,

All of these circuit board laminates are very abrasive so you should
always use carbide cutting tools. Use a spindle speed around 25,000
rpm to get a good cut. Slower speeds can be used but cut back on the
feed rate. I have always used .093" and .125" cutters in both CNC and
manual pin routers with good success. The bits seem to be shot after
about 100 feet of cutting. No matter which material we were cutting
there was always the fine dust and never any chips. Our machines were
equipped with vacuum extraction systems so it wasn't too bad but even
with a vacuum system the dust was still a mess.

If you are working with CEM-1 why not try scribing a line and then
snapping the laminate on this scored line. You will be surprised at
how clean of a break you will get. This works great as long as all of
the cuts are straight lines. You could even try one of those ceramic
tile cutters to put in the score line and then snap the edges off.

Tom