FANUC A20B-2003-0311 Spindle Motor Encoder PCB

The FANUC A20B-2003-0311 Spindle Motor Encoder PCB is a spindle motor encoder PCB that provides precise feedback on spindle speed and position for Fanuc CNC systems, using a magnetic or incremental encoder (model dependent) to generate pulse signals to the controller. It is mounted internally on the spindle motor or encoder assembly, enabling tight synchronization between spindle rotation and axis movement, which is essential for accurate threading, rigid tapping, and coordinated motion in automated machining. This component is designed for Fanuc CNC controllers (16i, 18i, 21i and similar) and delivers pulse feedback to the CNC controller to maintain precise spindle positioning and speed control. It is commonly available new, surplus, or refurbished and is considered a legacy/discontinued component, often used in repairs, replacements, or restoration of older Fanuc systems. Common replacements include Fanuc A20B-2003-0311/01A, A20B-2003-0310, and A20B-2002-0300.