The URS-B Series provides precision 360° continuous motion in a low profile package. They meet the requirements of numerous research and industrial applications and some are directly compatible with Newport's VP (URS75B), XM, GTS, ILS (URS100B), IMS (URS100B and URS150B) and other series of linear stages. URS-B rotation stages are available in two versions:The URS75BCC to URS150BCC DC-motor versions features an ultra-high resolution 8,000 cts/rev rotary encoder with index pulse for precision homing and is the recommended choice for applications requiring accurate bi-directional positioning. For the tightest position control, the rotary encoder is mounted directly on the worm screw. This eliminates most of the possible error sources associated with indirect read feedback devices. The high-torque of some DC motor versions provides the highest dynamic speed range and allows for rotating speeds up to 80 °/s. The URS50BCC DC-version is our smallest version and its motor encoder feature provides a very compact and easy to integrate version which can go up to 20 °/s with 100 N maximum load capacity.The stepper motor version is a more economical version for less demanding applications. When used with motion controllers with high micro-step capability, like the XPS or ESP301, low noise operation and very small incremental motions are guaranteed. The stepper motor versions do not use encoder feedback, but reach a position by the number of commanded steps and micro-steps. For this purpose, the stepper motor is directly attached to the worm screw using a proprietary bellows coupling that has a high torsional stiffness, eliminating the need for a gear or belt drive. The high output torque of the stepper motor minimizes the risk of lost steps and provides good linearity between commanded microsteps and the actual motion of the stage.Furthermore, except for the URS50B stages, all other versions feature adjustable limit switches to prevent over travel.All URS-B rotation stages feature a proprietary ball bearing to provides a low-profile compact stage with exceptional stiffness, high reliability and outstanding wobble and eccentricity. The tilted worm screw arrangement allows for 4 symmetric mounting holes as compared to other designs that only feature 2 or 3 mounting holes. This enables the URS-B stages to provide better support of higher or off-centered loads. Additionally, the flexible preloading system for the worm gear was improved to guarantee a backlash-free operation with an MTBF of 20,000 hours.The URS is available in vacuum compatible versions to 10e-6hPa. See the URS75BPPV6 .