Abstract: A multi-axis manipulator in the form of a robotic arm includes a safety disc (41) and safety collar (42) at one or more of the pivoting joints (14, 17, 19, 21, 23) thereof. The disc and collar define a small running clearance in normal use, but make contact in the event of excessive wear or failure of the rotary bearing at the respective joint. An inspection window (48) permits the running clearance to be checked, and the collar may comprise a caliper brake.