WhatsApp: +86 16626708626
Email: 
Phone: +86 16626708626Description
Key Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | A860-2109-T302 |
| Encoder Type | Incremental rotary encoder (Pulse Coder) |
| Series | FANUC αi Series (Alpha i) |
| Maximum Speed | 10,000 min⁻¹ (RPM) |
| Flange Size | 68 mm square flange |
| Shaft Diameter | 15 mm (solid shaft) |
| Connector | 17-pin military-style barrel socket |
| Supply Voltage | 5–30 VDC (typical 24 VDC in CNC applications) |
| Output Type | Incremental A/B/Z phases (open-collector or voltage output) |
| Resolution | 2048 CPR (cycles/rev) typical for αi spindle applications |
| Output Circuit | Open-collector / voltage output (model-dependent) |
| Current Consumption | ≤ 80 mA (typical) |
| Protection Rating | IP65 (sealed against coolant and chips) |
| Operating Temperature | 0°C to +45°C (inside machine enclosure) |
| Weight | ~0.3–0.5 kg (varies by listing) |
| Mounting | Direct flange mount to spindle motor or external spindle encoder bracket |
| Cable Length | Typically 1–3 m (custom lengths available) |
| Typical Use | Spindle orientation, rigid tapping, C-axis control, speed feedback |
Product Introduction
The FANUC A860-2109-T302 is an αi Series incremental rotary encoder (Pulse Coder) used for spindle position and speed feedback in CNC machine tools. It delivers up to 10,000 RPM maximum speed with a 68 mm square flange and 17-pin military connector, commonly mounted on αi spindle motors or external spindle encoder brackets.
This encoder is chosen for its proven reliability in rigid tapping, spindle orientation, and C-axis control applications on legacy αi spindle drives. The 2048 CPR resolution and robust IP65 sealing make it suitable for harsh machine shop environments with coolant and chip exposure.
A860-2109-T302
A860-2109-T302
Troubleshooting Quick Reference
| Symptom | Possible Cause | Relevance to this Part | Quick Check Method | Recommendation |
|---|---|---|---|---|
| Spindle orientation alarm (SAPM/SPOA) | Encoder signal loss or phase error | ✅ High | Monitor A/B/Z pulses on oscilloscope; check CNC spindle diagnostic screen | Usually requires encoder replacement or cable repair |
| Erratic spindle speed display | Intermittent encoder feedback or noise | ⚠️ Medium | Check encoder cable shielding and routing; verify connector tightness | Replace encoder cable if damaged; re-route away from VFD/spindle power |
| No spindle feedback, drive fault | Encoder power supply failure or open circuit | ❌ Low | Measure 24 VDC at encoder connector pins; check fuse on drive | Check power supply and fuses before replacing encoder |
| Rigid tapping pitch error | Encoder resolution mismatch or Z-phase fault | ✅ High | Verify encoder CPR and Z-phase signal integrity; check parameter settings | Replace encoder if Z-phase is missing or unstable |
| Coolant ingress, encoder failure | Seal failure or damaged connector boot | ⚠️ Medium | Visual inspection for coolant inside encoder housing; check IP65 seal | Replace encoder and improve sealing; verify connector boot is intact |
| Encoder fails after swap | Wrong flange size, shaft diameter, or connector pinout | ✅ High | Compare old encoder label (flange, shaft, connector) before removal | Match exact part number and mechanical specs on replacement |
If you’re stuck, send photos of the encoder label, connector, and any spindle drive alarm screens. We’ll review them before you commit to a swap.
Frequently Asked Questions (FAQ)
Q: What’s the difference between A860-2109-T302 and A860-2000-T301?
A: Both are FANUC αi series incremental encoders. The A860-2109-T302 has a 68 mm square flange and 15 mm shaft, commonly used on αi spindle motors. The A860-2000-T301 is a smaller encoder with different flange and shaft dimensions. They are not mechanically interchangeable—match flange size and shaft diameter exactly.
Q: Can I use this encoder on non-FANUC spindle drives?
A: Yes, but only if the drive supports incremental A/B/Z encoder feedback with compatible voltage (5–30 VDC) and resolution (2048 CPR typical). You must verify pinout, supply voltage, and signal type (open-collector vs. voltage output) before integration.
Q: Will my spindle parameters survive an encoder swap?
A: Yes. The spindle parameters (gear ratios, orientation position, C-axis scaling) are stored in the CNC/spindle drive memory, not on the encoder itself. As long as you replace it with the same resolution and signal type, the existing parameters remain valid. Always back up your spindle parameters before hardware changes.
Q: Is this encoder compatible with αi-B or αi-F series spindle motors?
A: Mechanically, yes—the 68 mm flange and 17-pin connector are common across αi series. Electrically, verify resolution and signal type match the drive’s expectations. Some newer αi-B/αi-F motors use higher-resolution encoders; check the motor nameplate and drive manual.
Q: Why is this cheaper than buying direct from FANUC?
A: This is new surplus or inspected stock from decommissioned systems and authorized distributors. It’s genuine FANUC hardware, function-tested, but sold as surplus rather than factory-direct new. That’s why the price is lower while still carrying a 1-year replacement warranty.
Q: What condition is the unit in—new, used, or refurbished?
A: We list each unit explicitly: “New Original / New Surplus” means factory-sealed or unused surplus with original packaging; “Refurbished (tested)” means cleaned, electrically tested, and verified functional on an αi spindle encoder test rig. The product page or quote will state which applies.
Q: Do you provide test reports or signal waveforms?
A: Yes. For refurbished units, we can supply a basic functional test report (supply voltage, A/B/Z pulse integrity, max speed run-up) and short test video or oscilloscope capture on request. Just ask before purchase.
