One Accurate Measurement is Worth 1000 Expert Opinions

The Six Degrees of Freedom

Machine Tool Motions that can cause Positioning Errors

Machine tools with just 3 axes of movement can exhibit 18 individual motion errors (6 per axis), plus square between each pair of axes, for a total of 21 potential errors in machine tool motion.

Calibrating machine tools with lasers allows detection of these errors so they can be corrected and compensated, thereby reducing scrap and rework and increasing machine productivity.

As a machine tool table moves along its ways, it experiences motions from a number of degrees of freedom. This motion can result in inaccurate machine positioning along the axis of linear displacement. (see the figure below)

The six degrees of freedom are:

  1. Linear Positioning
  2. Pitch
  3. Yaw
  4. Roll
  5. Side to Side Straightness (Horizontal)
  6. Up and Down Straightness (Vertical)

To fully analyze a machine's positioning accuracy, the six possible positioning errors on each of threee axes and square between axes must be measured.