What is the purpose of the G43 command in CNC milling?

The G43 command in CNC milling is specifically used to activate the cutter height offset, which is crucial for compensating the tool length during the machining process. When a tool is called to the workpiece, its actual length may vary due to different tool sizes or types. By using the G43 command, the machine can reference a pre-set tool length offset stored in the control system. This allows the CNC machine to accurately position the tool at the correct height above the workpiece, ensuring that machining operations are performed at the intended depth.

This capability is essential for maintaining precision in machining, especially when using multiple tools of varying lengths in a program. By setting the cutter height offset, operators can avoid errors and inconsistencies that could arise from manually inputting the tool lengths, ultimately leading to better surface finishes and dimensional accuracy in the machined parts.