On 2010-07-22, DoN. Nichols wrote:
On 2010-07-22, Ignoramus24043 wrote:
I had a little light bulb go off in my head.

I think that I know what to do.

I will have functions that could combine different machining notions
together.

For example, say, I have a steel plate. I could make a circular cut
through it. If the plate is thick or hard, I may need to do it in
several passes, with plunging.

Even better is to ramp down as you circle. Plunging requires a
center-cutting mill. The ramp does not as you get slightly deeper as
you progress.

Great point.

Okay so far.

This really involves two separate concepts:

1) Generating the shape of the cut (circular, in this example)
and
2) Implementing a cut along an arbitrary shape, with several passes if
necessary

Also consider cutter compensation -- telling the CNC machine
what diameter cutter you are using, and which side of the cutter you are
using, and it generates a tool path to produce the shape you want -- or
complains if the drawing calls for a tighter radius in the pocket than
your mill can actually produce. Of course, you don't hit this
particular problem when cutting the outside of a rectangle.

you mean inside rectangle?

If I can do these two tasks separately, then I have a lot of
flexibility, as I could easily cut a square shaped hole in plate, egg
shaped, etc.

But if you don't separate (in time) the tasks, you can do the
ramp down instead.

Same applies to "milling out a deep pocket along an arbitrary shape".
Generating a shape is one thing, and removing material inside it (in
possibly several layers) is another.

This kind of approach, has potential for some very fun results.

Indeed so.

I will first try to just learn G codes, I think, but I started
experimenting with better way of writing those scripts. Basically a
CAM library in perl.

But I think that before running, I need to learn to walk, so, I will
practice using G-Codes in a non-idiosyncratic manner.

i


i