Multifunction Machine’s Stability Eases Superabrasive Grinding

Fives’ Cranfield Precision TTG concept is a multifunctional machine featuring a highly stiff, thermally stable foundation for a range of machining processes. While conventional machine tool platforms use stacked linear axes as the primary motion control system, this machine range coordinates two rotary axes and a short linear axis in a “Twin Turret” design. The TTG100 model handles workpieces as large as 100 mm in diameter, while the TTG400 handles workpieces as large as 400 mm in diameter.

A combination of rotary and linear axes produces relative motion (both position and angle) between tool and workpiece over a working area, providing advantages of stiffness and thermal stability. The machine base comprises two rotary, highly damped hydrostatic bearings that resist machining forces. The “Twin Turret” design includes a non-contacting labyrinth seal, making the machine base almost immune to distortions caused by the heat generated from the constantly changing coolant return path as the grinding wheel carriage moves along the linear axis, the company says.

This design provides a common platform for multiple machine configurations and processes, including OD, ID and profile grinding; milling; polishing; hard and diamond turning; dicing, and in-situ metrology. The machine’s stiff and stable machine design is intended to provide the accuracy required in universal grinding of conventional parts held in a chuck or faceplate using aluminum oxide or superabrasives.