Re: How to do circular milling in Bobcad 18?

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:

>
>
> 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

Thanks John... I guess bobcad is pretty simple. Some others will
automatically generate toolpaths with cutter comp.