So with my current settings do you think it will it cut a smooth arc useing
2 1/2 profiling ? 

Chris

In most CAM systems you can specify the segment length, this will then make the flats smaller or larger.

If you can just re-program VM to mill you a circle then it will output a G02/3 and the out side will then be smooth.

To mill a circle is very easy :-

(MILL 1.5 O/D BOSS WITH .375 DIA END MILL)

G20 G17 G80 G90
M6 T1
G43 H1
S1750 M3

G00 X.9375 Y0             (MOVE TO START)
Z0                               (MOVE TO TOP OF JOB)
G03 I-.9375 Z-.01 F5.    (MILL A CIRCLE AND MOVE DOWN .010")
G00 Z1.
M30

Graham.

Thanks for your help!!!

Once again about helical/spiral. Is there any developments on this way? Why is it so difficult is theare some imitations i pulsing engine can it be dun with G100? The reason I'm asking is the method of outputting helix as segments does not work very well in real life creating series of small movements lead to vibrations especially on servo driven machine's ( I use Melservo J2 ) even top of the range ones with is critical for mould making. I was about to try G100 with kind of similar to standard Mitsubishi controller what is your opinion is it worth spend money and time on? Thanks