What is the difference between G02 and G03, and how do they define circular interpolation in CNC programming?

G02 and G03 are G-codes used in CNC programming to define circular interpolation, which means moving the cutting tool along a circular path. The key difference between G02 and G03 is the direction of the arc. G02 specifies clockwise circular interpolation, while G03 specifies counter-clockwise circular interpolation. When using G02 or G03, you need to specify the endpoint of the arc and the location of the arc's center. The endpoint is specified using X, Y, and Z coordinates, just like in linear interpolation (G01). The arc center can be specified in two ways: using I, J, and K parameters, or using the R parameter. If using I, J, and K, they represent the incremental distances from the starting point of the arc to the center of the arc along the X, Y, and Z axes, respectively. If using the R parameter, it represents the radius of the arc. The CNC control system uses this information to calculate the toolpath along the circular arc. For example, G02 X2.0 Y1.0 I1.0 J0.0 would move the tool in a clockwise arc to the point X2.0 Y1.0, with the arc's center located 1 inch away from the starting point along the X-axis (I1.0) and 0 inches away along the Y-axis (J0.0). Similarly, G03 X2.0 Y1.0 R1.414 would move the tool in a counter-clockwise arc to the point X2.0 Y1.0 with a radius of 1.414 inches. The correct selection of G02 or G03 is crucial for machining circular features accurately. Choosing the wrong code will result in the tool moving in the opposite direction, creating an incorrect shape.