Fanuc A06B-0162-B775#0008 AC Servo Motor — αM6/3000, Keyed Shaft, 24V Brake, A64 Encoder

Product Overview

Part Number: A06B-0162-B775#0008

Alternate Part Number: A06B-0162-B775#7008

Also Searched As: A06B0162B775, FANUC A06B-0162-B775#0008, Fanuc A06B0162B7750008

Motor Model: αM6/3000

Series: Fanuc Original Alpha M Series

Classification: Fanuc Alpha M Series AC Brushless Servo Motor — 1.4 kW, 3,000 rpm, Straight Shaft with Keyway, 24V Spring-Applied Brake, A64 Incremental Encoder, IP65 | Discontinued by Manufacturer

Technical Specifications

Discontinued — What That Means for Sourcing

The A06B-0162-B775#0008 is discontinued by the original manufacturer. Fanuc no longer produces this part. For the many CNC machine tools and Fanuc robots still running the αM series in production environments worldwide, that fact creates a sourcing reality that every maintenance team managing these machines needs to plan around.

Discontinued status does not mean the motor is unobtainable. It means that aftermarket stock, exchange programs, and repair services are now the primary supply channels — not the OEM. Qualified servo motor distributors and repair facilities stock rebuilt and exchange units. The αM6/3000 motor body is well understood by experienced repair shops, and the failure modes — bearing wear, winding insulation degradation, A64 encoder deterioration, brake solenoid failure — are all serviceable at the component level.

What discontinued status does mean, practically: lead times on replacement units can be longer than for current-production motors, availability varies by region and time, and the price premium for good-condition units in the aftermarket reflects the reduced supply. Facilities running machines with this motor are well-advised to keep at least one exchange unit in inventory rather than relying on just-in-time sourcing when a failure occurs. A machine down while waiting for an αM6/3000 from the aftermarket is a production cost that a $2,000–3,000 spare on the shelf eliminates.

The #0008 and #7008 Suffixes — Same Motor, Different Nameplate

A frequent source of confusion in sourcing this motor: the #0008 and #7008 are the same physical motor. The suffix digit in Fanuc's original alpha motor numbering conveys two things: shaft configuration and encoder details in the last digits, and in the leading digit, the nameplate variation. The 7xxx series designates GE Fanuc branded nameplates — the North American market variant produced during the GE Fanuc joint venture period. The 0xxx series is the standard Fanuc nameplate. Both carry identical motor windings, identical shaft geometry, identical brake configuration, and identical A64 encoder. They are interchangeable as replacements for each other without any electrical or mechanical modification.

When searching for this part, both part numbers will appear in supplier catalogues. Either is the correct replacement for a machine currently fitted with the other.

αM Series: The Context This Motor Belongs In

The αM designation identifies a mid-generation update within Fanuc's original alpha servo platform — released after the base alpha series (α1/3000, α2/3000, α6/3000, etc.) to address specific application requirements, particularly Fanuc robot joint drives and certain machine tool applications where the standard alpha motor body's inertia characteristics did not optimally match the load dynamics.

The αM6/3000 at 1.4 kW and 3,000 rpm occupies a specific position in this family — more capable than the compact αM2/3000 and αM2.5/3000 robot joint motors, smaller than the αM9/3000 and larger variants. Applications where the αM6 was specified include medium joint drives on Fanuc industrial robots, primary feed axis drives on compact CNC machine tools with Fanuc Series 0 or 16 controls, and specific auxiliary axis applications where the αM body's torque-inertia characteristics suited the mechanical design better than a standard alpha motor of equivalent output.

The motor runs on 144V AC at 200Hz from a 200V amplifier supply — the electrical characteristics of the original Fanuc alpha SVU amplifier platform. This is emphatically not the 200V / 133Hz of the larger α22/2000 or α30/2000 motors, nor the higher voltage of HV variants. The 144V / 200Hz combination is specific to this motor frame and its matched amplifier module.

24V Spring-Applied Brake: Safety Engineering You Can Count On

The B775 suffix positions this motor in the braked variant of the αM6/3000 series, and the brake specification — 24V spring-applied — is the defining safety element that governs where this motor can and cannot safely be substituted.

Spring-applied brakes are fail-safe by design. The spring engages the brake disc mechanically whenever the brake coil is not energised — which means any loss of power, for any reason, results in an automatically held shaft. No control logic required, no CNC command needed, no amplifier active. Power off, spring on, shaft held. The coil must be energised to release the brake and allow shaft rotation, which means the motor shaft is mechanically braked as the default state and only rotates when deliberately and actively released.

At 1.4 kW and the applications the αM6/3000 serves — Fanuc robot joint drives and CNC machine tool vertical axis applications — the gravitational load that the brake must hold at servo-off is real. A robot arm joint that allows the arm to fall when the controller powers down creates safety hazards. A vertical quill axis that descends onto the workpiece at shutdown creates damage. The 24V spring brake on this motor is the mechanism that prevents both outcomes.

When replacing this motor, the brake wiring must be correctly reconnected and verified before returning the machine or robot to operation. Confirm brake engagement (shaft held, coil de-energised) and brake release (shaft free, 24V applied) before running any program. On Fanuc robots, confirm that the arm holds position correctly through a controlled power-down cycle after replacement. On CNC machine tools, verify the vertical axis does not move when the servo is intentionally disabled.

Straight Shaft with Keyway: Secure Coupling on a Legacy Platform

Every A06B-0162-B775#0008 carries a straight shaft with a machined keyway — the coupling interface that the machine or robot was built around, and the one that must be replicated exactly in any replacement.

The straight-plus-key configuration at 1.4 kW transmits torque through positive mechanical key engagement, preventing coupling slip under the reversing loads that occur during direction changes in servo axis positioning cycles. On a robot joint that changes direction thousands of times per shift, a purely friction-clamped coupling degrades progressively — the keyed configuration provides long-term torque transmission security without service attention.

For replacement, the transfer procedure is straightforward: remove the coupling hub from the failed motor using a proper gear puller applied against the hub face, inspect the key and keyway for fretting or deformation, fit the new motor with the key engaged correctly in both shaft and hub keyways, and secure the hub axially with the retention fastener torqued to specification. The alignment geometry repeats automatically because the straight shaft does not require the axial draw force and engagement precision of a taper shaft — the hub simply fits onto the shaft and the key registers the angular position.

A64 Incremental Encoder: Homing Required, Amplifier Generation Locked

The A64 on the A06B-0162-B775#0008 is a 64,000-count-per-revolution incremental encoder using the parallel encoder signal interface of the original Fanuc alpha platform. Two operational realities follow from this specification that every maintenance team running this motor must understand.

First: homing is required on every power-up. The A64 does not retain shaft position through power-off. When the CNC or robot controller powers on, every A64-equipped axis has no position data until it executes a reference-return (homing) movement to find its reference marker. On a CNC machine tool, this is the programmed reference-return cycle in the machine startup sequence. On a Fanuc robot, this is the mastering or zero-return procedure. Both are standard operating procedures for original alpha series equipment and are already built into the machine's startup sequence.

Second: this encoder is incompatible with αi series amplifiers. The A64 uses the original alpha platform's parallel encoder interface. Fanuc αi series amplifiers (αiSV) expect the serial encoder protocol of αiS and αiF motors. The two interfaces are electrically and logically different at the connector and protocol level — there is no parameter setting that makes an αiSV read an A64 encoder. The A06B-0162-B775#0008 requires an original Fanuc alpha SVU amplifier and cannot be substituted into an αi amplifier system without replacing both the motor and the amplifier as a matched pair.

At 64,000 counts per revolution, the A64 provides adequate position loop resolution for the applications it was designed for. On a medium robot joint or a CNC feed axis with a typical ball screw pitch, this resolution supports the positioning accuracy requirements these applications demand.

A06B-0162 Series: Variant Reference

All variants in the A06B-0162 series share the αM6/3000 motor body — 1.4 kW, 3,000 rpm, 144V, 6A. Shaft type, brake, and encoder distinguish the variants.

The B775 is the straight-keyed-shaft braked A64 configuration — the specific combination required for vertical axis and robot joint applications where a keyed coupling hub is already installed on the machine and gravitational load holding at servo-off is mandatory.

Amplifier and CNC Compatibility

The A06B-0162-B775#0008 requires an original Fanuc alpha series SVU amplifier — the first-generation alpha servo drive, not the αi generation. Compatible CNC platforms include Fanuc Series 0, 15, 16, and 18 on the original alpha amplifier generation, and Fanuc robot controllers from the same era.

This motor is not compatible with Fanuc αiSV amplifiers (αi generation) or with Fanuc β series drives. The A64 parallel encoder interface, the motor winding voltage (144V), and the motor type parameter set are all specific to the original alpha platform. Any attempt to use this motor with a non-matching amplifier will result in encoder communication failure, parameter mismatch faults, or incorrect motor drive behaviour.

When commissioning a replacement motor, verify that the axis parameters — motor type code, maximum current, and maximum speed — are correctly set for the αM6/3000 specification on the existing amplifier before allowing the axis to run under CNC control.

Typical Applications

Fanuc robot joint drives on original alpha generation robots. Medium-load joint axis drives on first and second generation Fanuc industrial robots where the αM6/3000 body was specified for its torque and inertia characteristics, and the 24V spring brake provides mandatory holding at servo-off on gravity-loaded joints.

CNC machine tool vertical axis and inclined feed drives. Z-axis quill drives, vertical ram feeds, and inclined slide drives on Fanuc Series 0 and 16 controlled machining centres where 1.4 kW rated output matches the axis load and the 24V spring brake provides mechanical safety holding at every servo-off event.

Compact CNC machining centre primary feed axes. X and Y axis drives on small-format machining centres controlled by Fanuc Series 0 or 0M where the αM6/3000 frame size and 3,000 rpm ceiling match the axis mechanical design.

Field replacement on machines still running original alpha amplifiers. Any Fanuc-controlled machine or robot where the original αM6/3000 motor has failed and a like-for-like replacement is required to restore production without converting the drive system to a newer platform.

FAQ

Q1: The #0008 and #7008 suffixes — are these two different motors?

No — they are the same motor. The leading digit of the suffix encodes the nameplate variant: 7xxx indicates a GE Fanuc branded nameplate (North American market), 0xxx is the standard Fanuc nameplate. Motor winding, shaft geometry (straight with keyway), brake configuration (24V spring), encoder (A64), and electrical specifications are identical between the two. Either part number is the correct replacement for the other on any machine.

Q2: This motor is discontinued — is it still obtainable and repairable?

Yes on both counts. The αM6/3000 remains available through the aftermarket — rebuild/exchange units, tested used stock, and repair services are all current options from specialist Fanuc servo motor suppliers. The motor is a well-documented, well-understood platform that qualified repair facilities service routinely. Bearing replacement, winding repair, A64 encoder replacement, and brake service are all performed as standard overhaul items. For facilities running multiple machines with this motor, maintaining a spare in inventory is strongly recommended given that OEM supply is closed and aftermarket lead times vary.

Q3: Does this motor need a homing cycle after every CNC or robot controller power-up?

Yes. The A64 is an incremental encoder with no power-off position retention. Every time the CNC or robot controller powers on, the axis must execute a reference-return (homing) movement to establish the machine or robot coordinate before any programmed motion is possible. This is standard behaviour for all original Fanuc alpha series equipment with A64 encoders — the machine or robot's startup sequence is already programmed to handle it automatically.

Q4: Can this motor be used with a modern Fanuc αiSV amplifier?

No — not without replacing the entire axis drive system. The A64 encoder uses the original alpha parallel encoder interface, which is electrically and logically incompatible with αiSV amplifiers that expect serial encoder protocol. Additionally, the motor winding characteristics differ from αiF/αiS motors. The A06B-0162-B775#0008 must be driven by an original Fanuc alpha SVU amplifier. An upgrade to αi requires replacing both the amplifier module and the motor, along with a full parameter reconfiguration.

Q5: Can a no-brake variant (such as the B575 series) replace this motor if a braked variant is unavailable?

Only after a formal assessment of the axis load conditions — and almost certainly not on any vertical axis or gravity-loaded robot joint. The B775 brake variant was specified specifically because the axis or joint carries a load that would move under gravity at servo-off. Replacing it with a no-brake motor removes the only mechanical safety mechanism that prevents that movement when the amplifier is de-energised. On confirmed horizontal axes with no gravitational component, the assessment may support a no-brake substitution — but this is an engineering determination that requires review of the machine documentation, not a field decision made under time pressure.