Counter Clockwise Arc Feed Move.
G03 is the counterpart of G02 command and is used to move the CNC machine along an arc in a counter-clockwise direction. It is used to perform circular interpolation counter-clockwise. The G03 command is used in the same way as the G02 command, with the same parameters (X, Y, Z, I, J, K, and F) used to specify the end point, center point, and feed rate of the motion respectively.
For example, G03 X10 Y5 Z0 I0 J0 K1 F100 would move the tool in a counter-clockwise arc, with the center of the arc at coordinates (0,0), ending at coordinates (10,5), at a feed rate of 100 units per minute.
Arc can be in 3 different planes, depending of G17, G18 or G19 modal state.
If motion in direction of rotation axis is specified then helical motion is generated.
Arc is specified in center format using IJK words or in radius format using R word.
Center format – arc center is defined with IJ (in XY plane), KI (in ZX plane) or JK (in YZ plane) words.
In incremental arc distance mode (G91.1) arc center is set as offset from start position.
In absolute arc distance mode (G90.1) arc center is set as distance from zero position.
Radius format – arc is defined with arc radius. This format is depreciated because it can in certain conditions produce cuts that are out of tolerances.
Number of rotations can be set with optional P word. If, for example, P3 is set then we have two full circles before final arc.
G03 <X..W @^> <IJK> <P> G03 <X..W @^> <R> <P>
% G21 G90 G91.1 G8 G17 G00 X0 Y0 Z0 G00 X30 G02 Z60 I-30 J0 P2 G02 Z120 I-30 J0 P2 G02 X-30 Z165 I-30 J0 P2 G01 X30 Y120 Z180 G03 Z120 I-30 J0 P2 G03 Z60 I-30 J0 P2 G03 Z0 I-30 J0 P2 G19 G00 X30 Y120 Z0 G03 X90 J0 K30 P2 G03 X150 J0 K30 P2 G03 X165 Y90 Z30 J0 K30 G18 G00 X165 Y90 Z30 G02 Y30 Z30 K0 I30 P2 G19 G00 X165 Y30 Z30 G02 X97.5 J-30 K0 P2 G02 X37.5 J-30 K0 P2 %