Drill roughing?

Mastercam has a roughing technique that I don't remember seeing in
hobby-scale CAM software. It drills out material. I've seen the
machinists using that (pre-roughing?) in deep and/or narrow cavities.

When would I use such a technique, what are the tradeoffs and is it
somthing that is machine-dependent? I.e. would it be reasonable to try on
a Sherline CNC mill?

Thanks,

Randy

Randy Gordon-Gilmore ,----.___________ ______________ _________________
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