The Eye of CNC Machines — Grating Ruler Explained

Added: 2026-05-23

[00:00:00]Often referred to as the eye of the machine tool, the grating ruler is an indispensable component used in high-end [music] CNC machines. It uses optical principles and moire fringe technology to measure extremely small position changes with very high accuracy. In machine tools, its main [music] job is position monitoring. It watches whether the axis accurately moves to the position required by the CNC system. If the actual position deviates from the target, the grating ruler feeds this error back and the CNC corrects the axis position. For CNC machines, having a grating ruler or not makes a huge difference. Without a grating ruler, the system is semi-closed loop control.

[00:00:39]Equipped with a grating ruler, the system achieves full closed-loop [music] control. Full closed-loop control can further eliminate backlash and lead screw errors, greatly improving machining accuracy and yield [music] rate. This benefit is especially evident in used machines or large machine tools.

[00:00:54][music] So, does your machine tool have a grating ruler? If you want to upgrade motion control, sensors, [music] or CNC peripherals, visit ato.com for professional solutions.