Relates to a carrier (1) for positioning objects (5), which are oriented in the Z direction of a coordinate system, in relation to laboratory articles. Z rods (12) comprise a Z guide (43), on a cage (10) carrying the individual drive wheel (17), on which the Z rod (12) is guided in the Z direction. Each drive wheel (17) comprises a section (41), which is tailored to the cross-section of the profiled rod (18) of the Z drive of the carrier (1), individually driven by a motor, on which the drive wheel (17) is seated so it is not rotatable and is displaceable by sliding in the Y direction. The carrier (1) is characterized in that the attack faces (40) of the profiled rods (18) for driving a drive wheel are larger than the attack faces of a profiled rod having a square cross-section but having equally large radius.