In the 3-point method, which direction should be the last save point when setting the TOOL frame?

The last save point in the 3-point method when setting the TOOL frame should be from the Y direction. This approach is critical because the Y direction typically allows for the establishment of a stable orientation relative to the tool's working surface. By defining the last point in the Y direction, you ensure that the tool's position is accurately defined with respect to the workpiece.

The importance of this method lies in its ability to establish a reference frame that considers the orientation of the tool in a meaningful way, allowing for precise movements. Using the Y direction as the last point helps in creating a consistent basis for subsequent calculations and positions, reflecting the tool's alignment to the workpiece effectively.

In contrast, focusing on the X or Z direction may not provide a sufficient reference for establishing the tool’s frame in all cases, as these axes can lead to ambiguities in orientation and may not fully consider the nuances of the tool's placement during operation. The diagonal approach, while useful in some contexts, does not provide the same level of precision for establishing the final orientation of the tool. Thus, opting for the Y direction not only aligns with best practices but enhances overall accuracy in robotic operations.