Product Details

FANUC A06B-0076-B503 is βiS B12/3000 AC servo motor with keyway shaft and built-in 24V holding brake, belonging to FANUC Beta iS servo series, compatible with βiS servo amplifiers and FANUC 0i-MF, 0i-MF Plus CNC systems. It is the brake-equipped variant of A06B-0076-B203. The integrated power-off electromagnetic brake locks the shaft once power is cut off, preventing vertical Z-axis dropping on heavy-duty vertical machining centers and large mold milling equipment. It adopts 200V three-phase AC power supply, rated speed 3000rpm, delivering higher continuous torque than B8 models for heavy roughing and finishing tasks. The B128iA absolute encoder retains position data after power-off and eliminates homing operation. The keyway shaft is designed for timing belt and pulley transmission, maintaining steady torque output and preventing slippage under heavy cyclic cutting load.

This servo motor integrates stator winding, moderate inertia rotor assembly, B128iA absolute encoder and spring static holding brake inside red-capped aluminum housing. The B128iA absolute encoder transmits high-precision angle feedback to servo amplifier, supporting closed-loop position, speed and torque control. The built-in brake is power-release type, only for static shaft holding instead of dynamic braking during high-speed movement. It matches standard synchronous pulley and gear coupling for belt-driven machine layout. Two separate connectors are arranged at the rear for power cable and encoder cable, following FANUC standard pin definition for convenient wiring and maintenance.

The front shaft sealing structure reaches IP65 protection grade, resisting coolant splashes, cutting oil mist and fine metal dust in CNC workshops. The internal bearing set uses long-life grease lubrication to sustain continuous medium-speed reciprocating cutting cycles. Its moderate rotor inertia balances high torque capacity and stable dynamic response, delivering smooth feed movement for heavy mold roughing and finishing. Users can adjust servo gain, soft limit and brake delay parameters on CNC system to match vertical axis gravity balance and the elastic property of belt transmission.

It serves as a direct replacement spare part for original keyway shaft βiS B12/3000 servo motors suffering from bearing abnormal noise, encoder signal loss, brake slip, shaft wear and winding burnout. Every unit will pass winding insulation test, encoder position reading test, brake holding force verification and servo amplifier matching test before shipment, ensuring stable torque output and reliable static locking performance. Replacing this servo motor can restore heavy-load medium-speed feed axis motion rapidly, avoid machine shutdown caused by cutting interruption and vertical axis sliding. It is widely deployed in heavy vertical milling centers, large mold processing equipment and other belt-driven CNC feed axis applications.