Study on high efficiency machining with reaction-free Shuttle Unit

Abstract

This paper introduces Shuttle Unit, attachable to an ultra precision milling machine, for high speed machining of micro-grooves and micro-dimples. The shuttle, which is pneumatically supported, is driven by a kind of linear motor at 1.2 m/s, reciprocating three times per second. The reaction of the Shuttle is compensated for by its unique reaction-free structure. This unit can machine 3 grooves in a second. The surface roughness of grooves is 1.0nm Ra. Grooves are fabricated sharply without burrs even in the groove pitch of 0.3 μm. It can also machine 200,000 dimples in 4.5 minutes. The error of each dimple's position is less than 1 μm even though Shuttle's speed is 1.2 m/s. The unit has achieved high efficiency machining and ultra high precision machining at the same time, thus resulting in shortening the machining time of optical parts such as light guiding panel mold and diffraction grating.