| A machine tool is provided with a toolsetting probe mounted on a bed or table, and a workpiece-sensing probe which can be mounted in a movable spindle. Both probes are calibrated by using them to make measurements against each other. The arbitrary length of the workpiece-sensing probe is used to calibrate the toolsetting probe, rather than using a pre-calibrated artefact of known length mounted in the spindle. A stylus disc of the toolsetting probe has a pre-calibrated size or dimension, and the workpiece-sensing probe is calibrated with respect to that. This obviates the need for skilful manual calibration procedures using pre-calibrated artefacts and manual measurement tools. |
