if you move X & Y at the same time you are moving in a plane not linear.

bill

Hi Bill

My interpretation is that the axis are moving in such a way that they generate a straight line between 2 point (linear), that straight line may be at an angle to all three axis but it is still the machines attempt at moving in a straight line.

For example this code from previous post

g1 x-.655 y.165 z-.060 a15 f5.0

Is still generating a linear interpolation it is only the fact that the A axis is a rotary axis that you get a non linear path and that IMHO is not the code doing this but the mechanical attribute of the rotary table; the same way a lathe generates a cylinder from a single point cutting tool and a linear movement.

Where as the code below does seem to be generating a non linear path that is non reliant on the mechanical generation of the path. The only caveat is that it is not using the 4th axis and the axis of rotation must be in a normal relationship to either the X, Y, or Z axis.

==============

G0 G49 G40 G17 G80 G50 G90

M6 T0 (TOOL DIA. 10)

G21 (mm)

M03 S0

G64

G00 G43 H0 Z1

X14.5 Y-5.75

G00 Z-2

G01 G42 P5 X8.75 F30

G02 X3 Y0 R5.75

G03 X-3 Y0 R3 Z-1.5

G03 X3 Y0 R3 Z-1

G03 X-3 Y0 R3 Z-0.5

G03 X3 Y0 R3 Z0

G03 X-3 Y0 R3 Z0.5

G02 X-8.75 Y-5.75 R5.75

G01 G40 X-14.5

G00 Z1

M5 M9

M30

=============

Are my conclusions correct?

Brian