Zero setting the rotatory B axis in the tool

1. Clamp long centre point (125mm) into spindle.
2. Allow dial gauge (90 increments offset by z) to touch the tool close to the clamping-in point.
3. Move machine up in positive Z position. When the tool stands straight, there must be no noteworthy deviation recognizable on the dial gauge (a 0.1 degree angular error produces a 0.1745 mm position error in the case of a 100 mm tool length).