Workholding Rotary Systems

Aug. 7, 2007
Two new rotary units deliver high-speed precision positioning, and their rugged designs promise long life.

Hardinge's DD200 rotary has high speed, high torque and high precision positioning.

The new DD200 DirectDrive Rotary system from Hardinge Inc. ( is a gearless high-speed, high-torque model with precision positioning and repeatability. The company said these features make it well suited for parts that require accurate angular positioning, as well as for high-speed, high-accuracy contouring applications. The direct-drive design eliminates backlash, providing high servo stiffness and rapid and accurate bidirectional response with repeatability of ±2 arc/sec. The DD200 unit is engineered for precision-part industries including aerospace, automotive, autosport, defense, medical, mold and die, electronics and energy/oil sectors.

Additional features of the DD200 include:
• Up to 2,100 degreesper-second indexing speed for increased productivity
• Wraparound torque motor for a smaller foot print
• Management of heat dissipation to maintain stability of the center line of the spindle to maximize process capability
• 4th-axis integration supported by Fanuc and Heidenhain allowing operators to take advantage of maximum machine capability including "lookahead" programming for high speed machining
• Semi 4th-axis operation using Hardinge's standalone Servo Control for use on CNC machines that can't support "pole position detect"
• Includes a 10-in. (254 mm) slotted face plate for ease of clamping on a generous surface
• A flexible collet-ready spindle that allows quick changeover from collets, expanding collets, step chucks, power chucks and face plates without an adapter

The DD200 has a small footprint due to its directdrive, rare-earth, frameless permanent-magnet torque motor that wraps around the spindle, eliminating the need for a separate motor extension. A high resolution ±0.077 arc/sec encoder is mounted directly to the spindle enabling ±3 arc/sec system accuracy for accurate positioning.

Lyndex-Nikken Inc. ( said the new 5AX-200II CNC Rotary Table performs with high accuracy and the fastest rotating and tilting speeds in the industry while providing high brake torque. The system's wear resistance, rigidity and rapid speeds are the result of its carbide worm system.

The carbide worm system uses a carbide worm screw and ion nitrided worm wheel, rather than a conventional bronze or bronze alloy actuation mechanism. When compared with standard bronze worm gears, the 5AX-200II CNC Rotary Table has an up to eight times reduction in friction and wear to drastically reduce backlash. The worm screw consists of a less brittle V-grade form of carbide, while the worm gear is ion nitrided to a depth of 0.1 mm and an external surface hardness of 68 Rc.These properties, as well as a steel way hardened to 58-60 Rc, enhance system rigidity and longevity.

The 5AX-200II allows for the machining of five sides of a workpiece, making it good for medical and aerospace 5-axis work.

The faceplate diameter of this rotary table is 200 mm and maximum work load is 176 lb. Various options are available to meet workholding, fixturing and chucking requirements.