Steinmeyer-FMD’s multi-axis air bearing gantry system is achieving speed accuracy with the help of Renishaw’s Tonic optical incremental encoder. Precision engineering precision optics company, Steinmeyer-FMD, has introduced the linear-axis gantry system for applications requiring ultra-high precision. Applications include laser machines, dispensing systems, inspection systems, pick-and- place machines gene chip production equipment.
The motion system consists of an XY stage utilising air bearings a conventional ball-screw-driven Z table, with the Tonic optical linear encoder providing incremental position feedback on all linear axes.
The motor concept is based on a wear- noise-less drive operating at very high speeds. Depending on the application, the XYZ design can be fitted with A B axes adapted to the required load, speed accuracy. Smooth velocity control is achieved as the Tonic encoder incorporates dynamic signal processing within the read head, providing an ultra-low sub-divisional error (SDE) for improved signal purity. The 0.5nm RMS jitter fine resolution result in an encoder that provides improved positional stability good low-speed velocity control.
Long-term operational reliability is said to be assured with the Tonic encoder’s filtering optics, which are now enhanced by Auto Gain Control (AGC) for signals that can withstdust, scratches light oils on the scale. The compact Tonic encoder is also available with a variety of high-accuracy linear rotary scales, 1nm 2nm resolution versions have recently been added to the range.
Tonic incremental encoders offer the features of a 20 micron pitch encoder, such as low cost of ownership dirt immunity, as well as achieving noise levels of much finer pitch encoders. The Steinmeyer-FMD stages are custom solutions optimised with regard to the required conditions.
XY specifications include: travel to 600mm x 600mm, positional accuracy to 10 microns, positioning repeatability of +/-1 micron, plus straightness flatness of one micron over the full travel range. Both X Y stages are driven by iron-less, electrodynamic linear motors with maximum acceleration of 10m/s2 XY velocity of 1,000mm/s.
Position feedback from the Tonic incremental encoder has a resolution of 50nm on the XY stage a positional accuracy of 10 microns on the Z-axis. Tonic incremental encoders are backed by a global support network are WEEE RoHS compliant.