[dwneumann]

I am trying to use a roughing strategy to cut a straight channel in a piece of rectangular stock using a zig-zag pattern along X axis.
(I specified a 3/8" flat-end cutter, 3/8" channel depth in .020" steps with 50% stepover).

The zig-zag pattern is followed, but the cuts don't go from one end of the work to the other as I would have expected, but rather the tool sometimes plunges somewhere in the middle and then "backtracks" to the edge of the work, changes direction, and cuts to the other edge, then rapids to another starting location not at an edge and starts cutting from there. I've attached photos of the model and the toolpath.

Why the crazy toolpath? Is there a configuration setting that I have forgot to set? Thanks for all suggestions....

[svenakela]

The toolpath isn't crazy at all. First of all, have said it many times, the cutting strategies are made for safe cutting in tough materials such as moulding steel, hardened steel, aged aluminium etc. Cutting edge to edge gives a material engagement that's bad in many perspectives and mainly it lowers the cutter life a lot.
Secondly, if you want to make a cut that gives a precise cutout (e.i. making your model to the toleranced dimensions) a rouging toolpath only is not the way to go. Roughing is roughing, it doesn't touch the material surfaces. If you want to make sure that your model is made to tolerance, you must use another toolpath as well.

If you really want to go edge-to-edge, make a rectangular slightly longer than your cut out and prepare a 2D profiling or pocketing.

/S

[dwneumann]

Thanks for the reply.
I discovered the cause of the odd toolpath... it was ramp angle combined with stock size.
Once I changed the ramp angle to 90 degrees and extended the stock size to model plus cutter radius, the toolpath oddness went away.

[svenakela]

What's the material you're cutting in?