Super Precision Indexing

The Hardinge DD100 high-speed, direct-drive Super-Precision rotary table is a high-speed parts positioner with ± 3 arcsecond accuracy and 4 arcsecond repeatability.

The Hardinge DD100 high-speed, direct-drive Super-Precision rotary table is a high-speed parts positioner with ± 3 arcsecond accuracy and 4 arcsecond repeatability. The direct-drive rotary tables are ideal for the aerospace and medical industries requiring super-precision parts. The positioner also works well for drill and tap and laser processing. The DD100 is capable of spindle speeds as high as 4,200 degrees-per-second and as much as 600-rpm continuous rotation. That’s more than 10 times faster than a gear-driven indexer. The A2-4 spindle nose accepts standard 5C tooling, when used with a collet closer, to provide high-precision gripping of many part shapes, sizes and materials. 5C gripping options include collets, expanding collets, step chucks for larger part diameters, jaw chucks and fixture plates.

Hardinge direct-drive rotary tables have a surprisingly simple design consisting of a housing, bearings, encoder and spindle. There are far fewer parts and no gears to wear. A rare earth, permanent-magnet DC torque motor is wrapped around the spindle and operates with a programmed gear ratio of one-to-one. The encoder is mounted directly to the spindle to provide super-precision position feedback. Direct-drive technology has proven to be a more efficient way to convert electrical energy directly into mechanical motion. The cross-roller spindle bearing is permanently lubricated for life. Because the direct-drive torque motor has no mechanical gearing, there is no backlash. And since there is no backlash, bidirectional movement can be made without the need to compensate for backlash error. Hardinge systems guarantee a maximum runout of 0.0002 TIR.

The standard DD100 rotary package uses the Hardinge direct-drive all-digital servo control and can be used with most any machine. However, the unit is most productive as a true fourth-axis. In this case, the unit is directly connected to the machine, fully operating with the other axes.