Abstract: A method and apparatus for scanning an object (10) with a surface measurement probe (26) mounted on a coordinate positioning machine (24). Translational movement of the coordinate positioning machine (24) is used to move the probe along an at least part nominally spiral path about an axis (14) which intersects the object (10). The servo direction vector (16) for the probe (26) is directed nominally towards the axis (14) of the at least part nominally spiral path. The servo direction vector (16) for the probe is at an angle to said axis (14) of the nominally spiral path and at an angle to a plane perpendicular to said axis of the at least part nominally spiral path, which enables scanning of surfaces both parallel and perpendicular to the axis without the probe slipping off the surface of the object.