Re: Re: CNCPro

>
> Myself, I think I can say never. If a tool needs sharpening, I don't have

the equipment to sharpen it, so I would

> never have the need to compensate.
>

never say never ;-)

The main reason for cutter comp is not tool wear & the use of tooling that
is different from that which was used in the program. The primary reason is
to hold tight tolerances. If for instance you had to mill a slot that had a
+/-.002 inch tolerance. You would be able to cut this by programming with
offset curves in a Bobcad or Vector type of application. The usual way
would be to program the offset curve just larger than the tool radius,
measure the resulting size, then *reprogram* the part with the difference
between the desired size & that actually cut. The reprogramming would
involve drawing another offset curve & regenerating the portion of the
program involved with the slot.

With cutter comp capability, (G41/G42) The tool radius offset would be
changed from +.002 to whatever adjustment was needed to bring the slot to
size, then the same tested program would be rerun. While it is quite easy
to regenerate the entire program, and it will make as accurate of a part,
the chances for error are much greater when using an untested program or
even a regenerated one, vs just re-running one that you have already tested
out.

It is very easy to control turning on and off of cutter comp, by using the
approach and depart function. This generates a teardrop shaped construction
that allows a beginning straight move during which you turn cutter comp on,
and a corresponding straight ending move, during which you turn cutter comp
off. Bobcad allows you to do this manually, and Vector automates the
process.


Best Regards,

Fred Smith
IMService

imserv@...
Phone: 248-486-3600 or 800-386-1670
Fax:248-486-3698