Fanuc AC Servo Motor A06B-1424-B123#0321 A06B1424B123#0321 AO6B-1424-B123#O321

Fanuc A06B-1424-B123#0321 — αi 2/15,000 AC Spindle Motor, Flange Mount, Rear Sensor

Product Overview

Part Number: A06B-1424-B123#0321 Also Searched As: A06B1424B123, FANUC A06B-1424-B123, A06B-1424-B123 0321 Motor Model: αi 2/15,000 Classification: Fanuc Alpha i Series AC Spindle Motor — 15,000 RPM Maximum Speed, Flange Mount, Smooth Bore Shaft, Rear-Mounted Sensor, αiSP Amplifier Compatible

Technical Specifications

Fifteen Thousand RPM in a Compact Frame

Compact CNC machining centres, high-speed drill-tap machines, and precision die and mould equipment all share one demand that a conventional mid-speed spindle motor cannot satisfy: the ability to run small-diameter tooling at productive surface speeds.

A 3mm end mill needs roughly 15,000 rpm to hit the surface speed that carbide geometry was designed to exploit in aluminium alloy. Drop below that and you are either cutting slowly or loading the tool in ways that shorten its life.

The A06B-1424-B123#0321 is Fanuc's αi 2/15,000 — an AC spindle motor that was engineered precisely for this operating regime.

At 15,000 rpm maximum speed, it puts the full cutting parameter envelope of small-diameter carbide within reach for the machine it is installed in.

The motor's rated continuous output and torque characteristics at speed support productive material removal across the range of operations — from finishing passes where spindle speed is everything, down through moderate-load milling cycles where torque becomes a co-requirement alongside speed.

At 14.5 kg, this is not a heavyweight unit. That compact mass is deliberate — a lighter spindle motor means a lighter total spindle assembly, which translates to lower inertia for faster acceleration, less structural loading on the machine's spindle head, and a physical package that fits the compact machine designs where the αi 2/15,000 is typically specified.

What the #0321 Suffix Identifies

Fanuc's spindle motor suffix system encodes physical configuration details that define the exact motor assembly required for a specific machine design.

For the #0321, the four digits specify a factory-level configuration variant within the A06B-1424-B123 base series — covering the mounting flange geometry, the sensor interface arrangement, and potentially cooling or wiring specifics that differentiate this unit from other suffix variants such as #0021, #0521, or #0121.

The practical consequence: when ordering a replacement for a machine currently fitted with a #0321, the full suffix must be specified exactly.

A different suffix variant — even within the same αi 2/15,000 series — may carry different mounting hole patterns, different sensor wiring, or different cooling configurations that prevent correct installation or operation in the machine.

The A06B-1424-B123 base series is the motor family; the #0321 is the specific assembly within that family for a particular machine builder's spindle design.

Flange Mount and Smooth Bore — How This Motor Connects to the Machine

The flange mounting on the A06B-1424-B123#0321 means the motor attaches to the machine's spindle housing through a precision-ground bolt face at the front of the motor body.

The flange registers the motor's rotational axis to the machine's spindle axis through the mechanical precision of the flange-to-housing face contact — no shims, no base plate adjustment, no iterative alignment. When the flange registers correctly, the motor is aligned.

The smooth bore shaft (SLK) — no keyway — is the standard coupling interface for spindle motors in this class.

The motor rotor shaft connects to the machine spindle or spindle cartridge through the bore interface without a key engagement.

Torque is transmitted through the interference fit or coupling arrangement specific to the spindle design, not through a parallel key.

For the machine builder designing around this motor, the SLK interface keeps the coupling mass symmetrical and avoids any potential imbalance contribution from a key and keyway mass asymmetry — a real consideration at 15,000 rpm where even small imbalances create forces that affect bearing life and surface finish quality.

Rear-Mounted Sensor — The Spindle's Position Feedback Path

The rear sensor designation confirms that the spindle position feedback transducer — which provides the CNC with spindle angular position for rigid tapping, thread cutting synchronisation, and spindle orientation — is mounted at the non-drive end of the motor.

This placement keeps the sensor geometry clear of the drive-end coupling and toolholder interface, and typically gives cleaner access for sensor inspection and replacement without disturbing the spindle's mechanical drive arrangement.

The sensor enables three CNC functions that a speed-only spindle cannot perform:

Rigid tapping requires precise angular synchronisation between spindle rotation and Z-axis feed advance.

The tap pitch must be maintained through the full entry and reversal cycle without a floating tap holder.

The rear sensor provides the per-revolution angular reference the CNC interpolates against the linear axis position.

Thread cutting on turning centres and machining centres depends on a consistent reference pulse position each revolution so the cutting tool engages at the same angular position on every pass. Multi-start and precision thread forms require this repeatability across many passes.

Spindle orientation for automatic tool change positions the spindle to a commanded angular position before the toolchanger arm engages the toolholder.

Without position feedback from the rear sensor, orientation is not controllable to a defined angle.

Amplifier and CNC Compatibility

The A06B-1424-B123#0321 operates with Fanuc αi series spindle amplifiers (αiSP) — the spindle drive modules in Fanuc αi series drive cabinets.

The specific αiSP module rating required for this motor should be confirmed against the machine's electrical documentation, as multiple current ratings exist within the αiSP range to match spindle motors of different power classes.

Compatible CNC platforms include Fanuc Series 0i-D, 0i-F, 15i, 16i, 18i, 21i, 30i-A, 30i-B, 31i-A, 31i-B, and 32i.

The motor is not compatible with original α series (non-i) spindle amplifiers, which use a different drive architecture and motor interface, or with Fanuc β series spindle drives.

After fitting a replacement motor, verify the CNC spindle parameters — motor type code, maximum speed, gear ratio, and orientation offset — are correctly set for the αi 2/15,000 motor type before running production.

A parameter error on a spindle motor running at 15,000 rpm has more severe consequences than on a low-speed servo axis, so commissioning verification is not a step to skip.

Core Exchange Requirement

Like most Fanuc spindle motors, the A06B-1424-B123#0321 is supplied through a core exchange programme by most authorised distributors and repair facilities.

This means a rebuildable failed unit must be returned as part of the transaction, or a separate core charge applies to the purchase price.

The exchange model exists because functional recovery of the αi 2/15,000 motor body — bearing replacement, winding service, sensor replacement — requires a unit to rebuild. Suppliers who run exchange inventory need a consistent supply of cores to maintain their stock cycle.

For the buyer, exchange pricing is typically significantly lower than outright purchase pricing for the same unit. If the failed motor has suffered physical damage to the housing, rotor bore, or flange face, confirm with the supplier whether it qualifies as a valid exchange core before shipping it.

A06B-1424-B123 Series Variants

All variants share the αi 2/15,000 motor model — 15,000 rpm, flange mount, SLK shaft, rear sensor. Suffix digits encode factory-level configuration differences. Always specify the full part number including the #0321 suffix to ensure the correct physical assembly is supplied.

Typical Applications

High-speed vertical machining centres for die and mould work. 3-axis and 5-axis VMCs machining hardened tool steel and aluminium alloy where 15,000 rpm enables productive cutting with small-diameter ball-nose and flat end mills at cutting parameters that are not achievable at lower spindle speeds.

Compact drill-tap machining centres. High-cycle drill-tap machines producing threaded aluminium and non-ferrous workpieces where 15,000 rpm supports both fast drilling with small carbide drills and rigid tapping with the rear sensor providing the synchronisation the tap cycle requires.

Precision CNC machining centres for electronics and optical components. Machines producing complex precision parts from aluminium alloy, brass, and engineering plastics where high spindle speed combined with the motor's compact mass and low inertia allows fast spindle acceleration between tool positions.

Fanuc-controlled multi-axis machining platforms. 4 and 5-axis machining centres running complex contouring programmes where the motor's 15,000 rpm ceiling supports high surface speeds on small-diameter cutters making compound angular cuts.

FAQ

Q1: What is the maximum spindle speed this motor supports, and at what power does it operate continuously?

The A06B-1424-B123#0321 is rated for 15,000 rpm maximum speed. This is the design ceiling of the αi 2/15,000 motor, representing the speed at which the spindle bearing system, rotor balance, and motor electrical design intersect to define the safe operating limit.

Continuous rated power output is available across the motor's working speed range up to the rated speed point; above rated speed the motor enters the constant-power field-weakening region where available torque decreases as speed increases.

For duty cycles that include sustained operation near maximum speed, verify that the actual load demand at that speed stays within the motor's field-weakened torque capability.

Q2: Does the #0321 suffix matter when ordering — can a different suffix variant be substituted?

The suffix matters significantly for physical installation. Different suffix configurations within the same A06B-1424-B123 series can carry different flange bolt patterns, sensor wiring configurations, or cooling arrangements.

A wrong suffix may not mount correctly in the spindle housing or may have incompatible sensor wiring for the machine's electrical circuit.

Always specify the full part number A06B-1424-B123#0321 when ordering a replacement.

Do not substitute a different suffix without first confirming with the machine builder's documentation or a qualified Fanuc service engineer that the alternative configuration is mechanically and electrically compatible.

Q3: Which Fanuc amplifier is required for this motor?

The A06B-1424-B123#0321 requires a Fanuc αiSP series spindle amplifier. The specific αiSP module rating must match the motor's power class — confirm from the machine's drive cabinet documentation or original build specification.

Compatible CNC platforms include Fanuc Series 0i-D, 0i-F, 16i, 18i, 21i, 30i, and 31i. The motor is not compatible with original α (non-i) series spindle amplifiers. After replacement, verify the CNC spindle parameters are correctly set for the αi 2/15,000 motor type before returning the spindle to production operation.

Q4: Does this motor support through-spindle coolant delivery?

No. The αi 2/15,000 designation without a "T" identifies a standard configuration without the internal through-spindle coolant bore.

The αiT series (such as the A06B-1465 series) includes the internal coolant path for pressurised coolant delivery through the spindle to the toolholder.

This motor is designed for flood coolant or mist coolant machine configurations.

If the machine being serviced was originally specified with a through-coolant motor, confirm the motor's alphanumeric designation carefully before ordering — fitting a standard motor where a through-coolant model was specified leaves the through-coolant system without a delivery path.

Q5: Why is a core exchange typically required for this part?

Fanuc αi series spindle motors are not simple commodity items — they are precision assemblies whose components (bearings, windings, sensors, rotor) can be professionally rebuilt to restore full function.

The core exchange model allows the supply chain to maintain a stock of rebuild-ready units: the customer returns the failed motor as a core, the distributor or repair facility rebuilds it, and it re-enters inventory as a serviceable exchange unit. For the buyer, exchange pricing is normally substantially lower than outright purchase pricing for an equivalent quality unit.

For the supply chain, the exchange programme maintains the inventory depth needed to support a motor type that sees limited new production volume.

If the failed core has physical damage to the flange face, rotor bore, or housing that would prevent rebuild, discuss its acceptability as an exchange core with the supplier before shipping it.