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