The DT 58-DC rotary stage from Stein-meyer Inc., Burlington, Mass. (steinmeyer.com), is only 41.5-mm tall and weighs 1.4 kg, but can handle 100-N loads. Positional accuracy is 0.05° and repeatability is 0.03° with a typical surface run out of 20 m. It can move loads at 80°/sec with accelerations of 360°/sec 2 . A preloaded 180:1 worm gear drives the stage and includes a noncontact Hall-sensor reference switch. The unit is equipped with a dc motor and can be outfitted with either a rotary encoder with 500 pulses/rotation or a direct-reading incremental angular encoder with a resolution of 0.0005°.