Arc Interpolation

After understanding the functions of G0 and G1, we can now turn to the G2 and G3 commands, which are responsible for circular interpolation in CNC programming.

Think of G2 and G3 as artists drawing perfect circular and arc movements. While G0 and G1 handle linear movements, such as straight lines, G2 and G3 enable the cutting or engraving of circular paths.

The G2 command stands for clockwise circular interpolation (CW). It is like a painter drawing a circle in a clockwise direction, starting at a point and moving along a specified radius to form a precise arc or circle.

G3, on the other hand, is the counterpart to clockwise circular interpolation, namely counterclockwise (CCW) circular interpolation. It is as if the painter moves their brush in the opposite direction to create an arc or circle counterclockwise.

For both G2 and G3, additional parameters such as the start point, end point, and the radius of the circle or arc must be entered into the CNC program. In some cases, the center coordinates of the circle are used instead. These commands also take into account the feed rate (F), which determines how fast the tool moves along the circular path.

In summary, G2 and G3 extend the capabilities of G0 and G1 by enabling more complex and precise shapes beyond simple straight lines. They are essential for manufacturing parts with round or curved features and significantly contribute to the versatility of CNC technology.