System information

SECTION FOUR - PREPARATORY FUNCTIONS (G CODES)
Clockwise and Counterclockwise Directions
The view above is from the positive direction of the Z, Y, or X axis to the negative direction on
XY, XZ, YZ, or ZX plane in a right-hand Cartesian coordinate system.
Method I
Describing an Arc Using Incremental Center
The end point of an arc is specified by address X, Y, or Z and is expressed as an absolute or
incremental value depending on G90 or G91. In incremental, the coordinate of the end point is
related to the start point of the arc. The arc center is defined by I, J, and K for the X, Y, and Z
axes. The numerical value foll by the tool
owing I, J, or K is the distance from the start point to the arc center in X, Y, or Z axes. I, J, and K
are always incremental values independent of G90 and G91.
The sign of I, J, and K depends on the relationship of the center to the start point as shown
below.
Method II
Describing an Arc Using a Radius
When describing an arc using a radius value, there are a number of valid formats. The various
command formats are as follows.
G17 G02 X____ Y____ R____
G18 or X____ Z____ R____
G19 G03 Y____ Z____ R____
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