Re: [CAD_CAM_EDM_DRO] Technique for parting a part

Rob wrote:

> While I'm still very much a newbie, I have a question I just can't
> seem to figure out.
>
> If you start with a billet of say aluminum and you want to cut out a
> part, what are the stratagies for removing the part from the excess
> stock material? Should I program my NC code to cut all the way
> through into some scrap material?

Usually, you start off using other machines (bandsaws, for instance)
to cut a workpiece off the stock, leaving just enough extra to correct
for uneven cuts. Sometimes, especially when making many parts, you
can come up with a strategy to mount a long bar in the vise, mill out
the part and separate it from the stock, and then advance the bar for
the next piece. But, usually, a mill is much slower and more wasteful
of material than a saw.

> Also - how about cutting 2 sides of a part? Would you generate NC
> code to cut the first side, then flip the part and run NC code to
> cut the other side?

This is a pretty common practice. I usually hold work in a vise directly.
Sometimes, like when the entire perimiter of a part needs to be cut to
some tricky shape, I bolt the workpiece to a sacrificial fixture or
"scab plate" that is clamped in the vise, so that the workpiece is
held above the vise, and 5 sides can be machined. The less times
you have to remount a part, the more accurate it is likely to be.
(Also, the fewer chances for mistakes.)

Jon