Hi,?
many of the holes I mill are 3.2mm diameter and bigger, ie they leave a little divot....so what, it still works.
I hold the PCB blank down with double sided tape and the little divot mostly stays in place, but even if it comes loose
it presents no problems. I did three 6mm diameter holes today without problem.
Craig
toggle quoted message
Show quoted text
Hi John,
as of my point of view, this feature would be highly appreciated.
In the past (and obviously still...) I drill holes on the CNC mill all with the 1 mm drill bit I use for through hole parts and lastly take the board to my drill press and drill the final diameter with a borer of fitting diameter.
I cannot follow Art Eckstein on leaving the dot in the middle of bigger holes alone.
Thinking of something bigger, let's say a 10 mm hole, using the mentioned 1,5 mm endmill, the remaining dot will probably interact in some way with the endmill.
So I would prefer digging into the board beginning in the middle and carving outwards (you proposed this as "sort-of center-out strategy").
There exists a german tool named Estlcam. This tool already has this feature implemented (for standard milling jobs) and it performs well in milling holes and planes. From there I know, that the the answer to your question:
What about increasing the diameter if concentric holes or multiple passes are used?
should be "not more than 45% to prevent remainders on some curvatures". Perhaps this is not true for circles only? Don't know.
--
Harald
_____________________
