Re: [CAD_CAM_EDM_DRO] How to do circular milling in Bobcad 18?

dspinnett wrote:

>HI, I'm trying to figure out which cam software to get.
>I'm playing with Bobcad 18, and I can't figure out how to mill out a
>simple circle.
>
>Bascially, I just want to be able to cut a 2" hole in some stock
>with an end mill. I want to ramp into the cut, rough it out then
>take a full depth (.5) finish pass.
>
>Any advice? I don't see an option for circular cutting anywhere. The
>closest I see is pocketing, but thats not quite right.
>
>

The basic operation is you draw the circle, then create an offset from that
arc by the radius of the end mill. You then go to the cam side and tell
it you want to cut a chain, you point to the beginning of the arc, and the
direction you want to cut, and then either point to the end of the arc
or hit esc, and it should generate the G-code to cut that circle. If you
want to make a rough cut slightly inside the final cut, you need to draw
another offset line inside the first offset, cut that first, then cut the
final pass.

I don't use Bobcad/CAM for simple stuff like this, it doesn't need CAD,
and I have better trepanning algorithms.

I don't think Bobcad knows "trepanning", cutting shapes into sheet metal
so that the "blank" can just drop out.

You might look at some of my programs at
http://jelinux.pico-systems.com/gcode.html

check "Make Ring" for the program to trepan out a round hole. it makes
a series of
circular passes at a roughing diameter until the final depth is reached,
then expands to the
final diameter for a finish pass.

Jon