Planmeca ProMax 3D Max with ProTouch Technical Manual page 145

5 Panoramic and 3D calibrations
7. If the centre ball is too narrow, manually move the shoulder arm
forwards.
1. Make sure that the alignment pin is in the hole in the shoulder joint
(1).
2. Loosen the screws of the adjustment plate (2).
3. Move the shoulder arm forwards (3).
Move the arm forwards until the Shoulder value increases by 20 on the
interface:
Technical manual Planmeca ProMax 3D Max 139