1pc FANUC Encoder A860-2010-T341 New A8602010T341 A860-2010-T341

FANUC A860-2010-T341 Pulse Coder — aiAR128 Sealed Absolute Encoder for Alpha i Series Servo Motors, New

Some components in a FANUC servo system can degrade gradually — the machine develops positional drift, intermittent alarms, inconsistent contouring. Other times the failure is immediate: encoder alarm, axis shutdown, production stopped. Either way, the encoder is almost always the component you're tracking down.

The FANUC A860-2010-T341 is the sealed aiAR128 absolute pulse coder for FANUC Alpha i series AC servo motors — a widely deployed feedback device that also carries the designation ENCODER AIAB128 and directly replaces the earlier A860-2014-T301.

This unit is new.

What the aiAR128 Delivers

The designation aiAR128 places this encoder firmly in FANUC's Alpha i generation of serial absolute pulse coders.

The "AR128" component refers to the 128-fold resolution class within the absolute encoder family — the encoder delivers high-resolution absolute position data via FANUC's high-speed serial communication link to the servo amplifier, enabling the tight closed-loop control that Alpha i series drives were designed around.

As an absolute encoder, the A860-2010-T341 retains axis position data through power cycles, backed by battery in the servo amplifier.

Machine restart doesn't require a reference return homing sequence — the drive reads the encoder at power-up and immediately knows the axis position.

That's a meaningful operational advantage for production machines where restart time translates directly to production output.

Technical Specifications

The Tapered Shaft Mount — What It Means Practically

The TPR (tapered shaft) mounting distinguishes this encoder from straight-shaft variants. In the tapered design, the encoder coupling engages a matching tapered bore in the encoder body — the taper creates a self-centering, high-friction interference fit when the retaining bolt is tightened.

This mounting method has two practical advantages.

First, it eliminates play at the encoder coupling interface: unlike a keyed or clamp-style coupling, a properly seated taper produces no angular backlash between the motor shaft and the encoder sensing element.

Second, it resists loosening under vibration better than many alternative fastening methods, which matters on servo motors that experience repeated rapid acceleration and deceleration cycles over millions of operating hours.

IP67 Sealed Housing — Protection That Pays Off Over Time

The sealed housing on the A860-2010-T341 provides IP67 ingress protection — total dust exclusion and the ability to withstand water immersion up to one metre depth. That's a step beyond the IP65 rating of many earlier FANUC encoder variants.

On a CNC machine tool in production, the motor end of a servo sits in an environment where coolant spray, cutting fluid mist, oil aerosol, and chip-laden air are all routine. An optical encoder that loses its sealing — through a cracked housing, a degraded O-ring, or an inadequate IP rating — will accumulate contamination on the optical disk over time.

The degradation is often gradual: marginally noisy position signals become increasingly erratic before producing a clean alarm, and the machine may run with reduced accuracy long before it actually stops.

The IP67 construction is the correct answer to this environment.

For motors installed in wash-down areas, near coolant nozzles, or in any application with liquid exposure, the sealed design is not optional — it's what makes long-term reliability possible.

Replaces A860-2014-T301 — A Direct Current Supersession

One of the confirmed and documented facts about the A860-2010-T341 is that it is the current replacement for the A860-2014-T301.

Machines that were originally equipped with the A860-2014-T301 encoder use the A860-2010-T341 as the current-production direct replacement — same electrical interface, same mounting configuration, same compatibility with the servo amplifier and CNC control.

This supersession matters for maintenance teams who may be searching by the old part number.

If the encoder label on your motor reads A860-2014-T301, the A860-2010-T341 is what you order.

Where This Encoder Is Working

The FANUC Alpha i series AC servo motor platform has been the backbone of FANUC-controlled CNC machine tools since the early 2000s, and the aiAR128 pulse coder family is one of the most frequently encountered encoder specifications in that installed base. The A860-2010-T341 is found in:

CNC Machining Centers — axis drive feedback on X, Y, Z, and rotary axes of vertical and horizontal machining centers from builders including Mazak, Okuma, Makino, DMG Mori, Doosan, and many others

CNC Turning Centers — axis servo feedback on two-axis and multi-axis CNC lathes, including sub-spindle and C-axis drives

FANUC Industrial Robots — joint axis feedback on M and R series articulated robots using Alpha i servo motors at the arm joints

Flexible Manufacturing Systems — servo drives on pallet changers, conveyor indexers, and automated material handling systems built around FANUC Alpha i drives

Dedicated Production Equipment — custom automation cells in automotive, aerospace, and general manufacturing industries

FAQ

Q1: Does the A860-2010-T341 directly replace the A860-2014-T301?

Yes — the A860-2010-T341 is FANUC's current-production replacement for the A860-2014-T301. Both units serve the same motor family with the same serial absolute feedback interface. If the encoder label on your motor reads A860-2014-T301, ordering the A860-2010-T341 is the correct supersession.

Q2: Is the A860-2010-T341 an absolute or incremental encoder?

It is absolute. It outputs continuous shaft position data through FANUC's high-speed serial link, and position is retained through power-off with battery backup in the servo amplifier.

This eliminates the need for an axis reference return homing cycle at each machine startup.

Q3: What servo amplifiers and CNC controls are compatible with this encoder?

The A860-2010-T341 is designed for FANUC αi and βi series servo amplifiers, paired with CNC controls in the 0i, 16i/18i/21i, and 30i/31i/32i families.

It communicates over FANUC's high-speed serial feedback protocol, which is the standard interface for Alpha i and Beta i series motor-amplifier combinations.

Q4: What FANUC alarms indicate a failed A860-2010-T341?

Encoder-related failures typically trigger SV servo alarms on the CNC display — commonly SV0364 (CSAL alarm), SV0368 (soft phase alarm), or communication-related alarm codes indicating loss of or corruption in encoder serial data.

Before replacing the encoder, inspect the encoder cable and connector at both ends, as cable damage and connector corrosion produce identical alarm codes.

Q5: Why does the tapered shaft design matter for this encoder?

The tapered shaft (TPR) mount creates a self-centering, backlash-free connection between the motor shaft and the encoder coupling.

Unlike keyed or clamp-style couplings, the taper generates a precise interference fit when properly torqued, eliminating angular play and resisting loosening under vibration. This directly affects the quality and consistency of position feedback delivered to the servo drive.