When the load must go where it is told — low backlash, high stiffness, repeatable index — the drive is a planetary set on a servo loop. Harmonic and hollow rotary tables stay off this page until they are confirmed stock lines.
Planetary reducers on servo loops. Backlash class quoted from engineering. Harmonic gear reducers (strain wave gearing) and hollow rotary actuators are listed in the classification and stay off this page until they are confirmed stock lines. Named robot OEMs wait on written approval.
Challenge. Hold index under cut; fail-safe on power loss.
Solution. Planetary for stiff torque; brake. RV self-lock as the slow, heavy alternative. Positioning and repeat figures wait on a measured protocol.
Planetary gear reducers → · Worm gear reducers (RV series) →
Challenge. Process accuracy tracks backlash and repeatability on laser and marking tables.
Solution. Planetary reducer (arc-min class from engineering) + servo closed loop; stiff output shaft under load.