Renishaw has developed a track-mounting linear encoder scale system that combines ±5µm/m accuracy with the ruggedness of stainless steel and the rapid installation of a carrier-type encoder system. The Fastrack system is aimed at applications requiring high accuracy and easily removable scales.

The system uses two miniature guide rails to hold the low-profile scales that are free to expand at their own rate with almost no hysteresis. The system is suitable for applications where the expansion of the scale must be independent of the machine structure. If damaged, the scale can be removed from the rails and replaced quickly.

The 0.2mm-thick and 8mm-wide scales can be used with Renishaw’s RTLC incremental scale and compact Tonic readhead, or with its new Resolute linear absolute encoder and RTLA absolute scale. In either case, the encoders offer resolutions to 1nm, low sub-divisional errors, and low jitter for smooth velocity control and positional stability.

The self-adhesive guide rails come with sacrificial spacers which are removed when they have been fixed to an axis. The scale is then fed in from either end and glued or clamped to the substrate at a datum point anywhere along the axis. For incremental scale installations, limit magnets and a reference mark selector can also be fitted.

The scales, which are supplied on reels, can be cut-to-length at the point of installation. The system is suitable for large machines that need to be taken apart for transport to their installation site. Separate sections of scale can run across the joins (with gaps of up to 25mm). The scale can be installed, removed and re-installed as many times as needed.