Rockwell Automation 8520 9/Series CNC Lathe User Manual

Page 347

Chapter 13

Coordinate Control

13-5

Usually, workpieces on CNC lathes are cylindrical. The control allows
workpiece dimensions programming as either radius or diameter values.

G08 places the control in diameter programming mode. This mode

remains active until cancelled by a G07.

G07 places the control in radius programming mode. This mode remains

active until cancelled by a G08.

Either G08 or G07 can be selected by your system installer in AMP to be

the active mode at power-up. The currently active G-code can be

displayed by selecting the status screen. See section 8.1.

If program execution branches to a subprogram that changes to radius or

diameter mode, the control always reverts to the mode of the calling

program when subprogram execution is completed.

Example 13.3

Diameter/Radius Programming

Assume X is the diameter axis

Diameter Programming Mode (G08)

Radius Programming Mode (G07)

Incremental

G90G00X0Z35;
G91G01F.1X12;
Z-10
G02Z-4X8I4;
G01Z-15;

G90G00X0Z35;
G91G01F.1X6;
Z-10
G02Z-4X4I4;
G01Z-15;

Absolute

G90G00X0Z35;
G01F.1X12;
Z25;
G02Z21X20I4;
G01Z6;

G90G00X0Z35;
G01F.1X6;
Z25;
G02Z21X10I4;
G01Z6;

13.4

Radius/Diameter Modes

(G07, G08)