FANUC A06B-0061-B303 βiS 2/4000 Servo Motor with Tapered Shaft and 24V Brake

This configuration is suitable for machine axes that require the motor shaft to be held after controlled motion has stopped and servo power is removed. It must be paired with the correct FANUC amplifier, brake-control circuit and CNC motor parameters.

Verified Motor and Brake Data

• Manufacturer: FANUC
• Part number: A06B-0061-B303
• Motor model: βiS 2/4000
• Rated output: 0.5 kW
• Stall torque: 2 N·m
• Stall current: 3.3 A RMS
• Rated and maximum speed: 4,000 min⁻¹
• Maximum motor torque: 7 N·m
• Shaft: Tapered shaft
• Feedback: βiA128 absolute pulse coder
• Brake type: Built-in holding brake
• Brake supply: 24 VDC ±10%
• Brake holding torque: 3 N·m
• Brake current: 0.9 A

Holding Brake Function

The built-in brake is designed to hold a stationary shaft, including on an appropriately engineered vertical axis. It is not a service brake and should not be repeatedly applied to stop a rotating motor. The servo system must first decelerate and stop the axis before the holding brake engages.

FANUC documentation specifies a 24 VDC brake circuit and advises against sharing the brake supply with the CNC or amplifier control-power supply. The original machine circuit and brake-release sequence should be retained.

Tapered Shaft with B128iA Feedback

The tapered shaft must match the original coupling and machine-side attachment. The βiA128, often written as B128iA in parts listings, supplies absolute rotor-position feedback. Confirm encoder compatibility and backup-battery condition before disconnecting the motor.

B003, B303 and B403 Differences

A06B-0061-B003 has a tapered shaft without a brake. A06B-0061-B303 retains the tapered shaft and adds the 24 VDC holding brake. A06B-0061-B403 combines a straight shaft with a brake. Similar performance ratings do not make these versions mechanically interchangeable.

IP67 Suffix Identification

A06B-0061-B303#0100 is identified separately as the sealed IP67 version. IP67 protection must not be assumed for an unsuffixed A06B-0061-B303. Check the complete number and all modification markings on the original nameplate.

Pre-Order Compatibility Check

Verify the complete FANUC number, tapered shaft, brake requirement, brake supply and connector, βiA128 feedback, mounting dimensions, compatible servo amplifier and CNC parameters before ordering.

100% Tested Supply from REACO CNC

REACO CNC supplies the FANUC A06B-0061-B303 servo motor for machine maintenance and replacement. Every available unit is 100% tested before shipment. Send us the original motor nameplate and connector photos if configuration assistance is required.

Worldwide DHL/UPS/FedEx shipping. Contact REACO CNC for current stock, condition, price and delivery time.