"Jon Elson" wrote in message
...
Ignoramus24043 wrote:

2) Implementing a cut along an arbitrary shape, with several passes if
necessary

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.
The generally suggested method is to ramp down while performing the cut,
rather than plunging in Z and then moving in XY. I have already converted
my "treprect" program that plunged first, then cut around the rectangular
shape, then made a finish pass at full depth. The new version, which I
haven't gotten up on my web page yet ramps down on the first side of each
level.
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.
If it is not a simple circle, oval or rectangle, then it may be better to
plan the whole thing on a CAD system. Bobcad/CAM, one of the lower-level
packages, will do this pretty much automatically. You give the pocket
outline, the depth, and set some parameters such as the step-over and
plunge increment, and have it draw an offset line to compensate for the
tool radius, and it will carve out the interior of the pattern
automatically. Pretty much any CAM system ought to be able to do the
same.

Dudn't dat Mach controller program do all this?
These are all standard routines in any Haas/fadal, etc.

If doing a curve with an underlying analytic function, that function can be
straightforwardly done in a macro, without the need for cad or cam.
Fadal supplies such a macro for an ellipse. I think it has to be done
quadrant by quadrant, but no biggie.
I've done such a macro for fishmouth chamfering.
--
EA

Jon