Re: [CAD_CAM_EDM_DRO] Newbie: G Code Programming Question

Hi George,

For normal coordinate location (for us hobbyists), the LL corner is a
good choice. This is quite often the way the part is drawn.
Occasionally, as for cylinder end covers, the center works out good.
I'd start out at the LL corner. If necessary, the other corners can be
used as well. If I use my vice aligned with the Y axis, I like to touch
off on the fixed jaw, which is aligned with the X axis, and in the
rear. Just don't forget which axis the drawing is made to. Bad things
happen if the coordinate "frames" don't match!

For tool radius compensation, first draw the part outline, then an
"offset" around the part is drawn. Programs like Vector CAD/CAM or
similar make this easy. Perhaps your CAD software has this. The offset
should be 1/2 the dia of the tool.

HTH

Alan KM6VV


gglines1 wrote:

>
> I'm just starting to CNC program in G-codes. I'm uing MillMaster
> Pro for Windows by Microkinetics on a mill/drill.
>
> My software doesn't have tool radius compensation and I'm looking
> for advice on how to approach programming toolpaths. I hope I can
> explain this clearly. I'm finding calculating the cutter waypoints
> tough.
>
> Should I CENTER the spindle on the workpiece origin (0,0) or the
> EDGE of the end mill on the workpiece origin 0,0? For example, let's
> say I have a 1" x 1" (I'll ignore Z) workpiece with a 3/4" end
> mill. If I set the center of the spindle (using absolute mode) on
> 0,0 (front left corner of workpiece), then I have to reposition the
> spindle by -.375 in both X and Y or half the distance of the cutter
> to get to the edge of the workpiece. The second way I could do it
> is to move the cutter to X-.375 Y-3.75 and then initalize that point
> as the origin (0,0).
>
> Any suggestions on which way to approach this?
>
> Many thanks,
>
> George
>
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