Troubleshooting Guide

How to Replace an Obsolete Servo Motor

Guide to replacing an obsolete servo motor with a compatible model. Includes what to measure, check, and send a supplier for a quote.

Identify the Failed Axis Before Replacing It

Read the nameplate on the original motor and drive to capture model code, rated power, rated torque, rated speed, voltage, and encoder type
Measure the mechanical interface: flange square size, pilot boss diameter, bolt circle, shaft diameter, keyway or smooth shaft, and shaft length
Identify the encoder type: incremental or absolute, and whether it is battery-backed for multi-turn position retention
Check the drive model to confirm if a motor from another brand requires a matching drive or if the existing drive can be reused
Verify the cable connector style and required length to ensure compatibility with the machine’s wiring harness
Confirm the brake option and holding torque, especially if the axis is vertical or subject to load when powered off
Review the inertia ratio between the motor and the load to ensure the new axis will tune properly and avoid overshoot or vibration

Avoid Common Mistakes When Selecting a Replacement

Matching only the power rating is not sufficient; torque, speed, and inertia ratio must align with the original
An encoder type mismatch can change homing behaviour, leading to startup errors or position drift
A motor from a different brand may not work with the existing drive due to protocol, connector, or feedback signal differences
Cable length and connector orientation must match the machine layout to avoid field modifications
A mismatched brake or holding torque can result in uncontrolled motion during power loss or emergency stop

What to Send a Supplier for a Quote

A clear photo of the motor and drive nameplate, including all model numbers and ratings
A drawing or measurement sketch of the mechanical interface: flange, shaft, keyway, and bolt circle
Details on the encoder type: incremental or absolute, and whether it is battery-backed
The drive model number or a photo of its nameplate
The cable connector style and required length
The brake option and holding torque requirement
The intended application: vertical axis, high inertia load, or high-speed indexing

Components

Parts Covered in This Guide

Batch of AC servo motors individually bagged with power and encoder leads, packed for despatch

Automation PLC and Motion Components

Servo Motors and Drives

Mrright supplies AC servo motors with matched drives, power cables, and encoder cables for positioning axes. Each motor is quoted with the drive and cables that are compatible, so the axis arrives ready to commission.

Direct drive rotary table with hollow centre bore, mounting base and cable glands

Automation PLC and Motion Components

Torque Motor and DD Motor

Mrright supplies torque motors and direct drive (DD) motors with their matched drives from stock in Zhuhai. These motors are designed for low-speed, high-torque applications where backlash must be eliminated, such as indexing tables, rotary stages, capping and labelling heads, and wafer or panel handling.

Other Guides

FAQ

Questions on This Topic

Can I replace an obsolete servo motor with one from a different brand?

Yes, if the motor matches the mechanical interface, torque, speed, and encoder type. The drive must also be compatible or replaced with a matched unit.

Do I need to send the original drive to get a replacement motor?

No. Send the drive model number or a photo of its nameplate. We will confirm if the motor can be paired with it or if a new drive is needed.

What if the encoder type is different on the replacement motor?

A different encoder type may change homing behaviour. We will confirm if the new encoder requires a different tuning strategy or drive setting.

Can you quote a motor and drive as a matched set if the original brand is discontinued?

Yes. We carry multiple brands in stock. Send the nameplate photo or model number and we will quote a compatible matched set.

Is a single-unit replacement accepted for an obsolete servo motor?

Yes. Single-unit orders are accepted. We confirm flange, shaft, and encoder compatibility before shipping.

Send the Part and Skip the Guesswork

A nameplate photo answers most of the questions above in one message.

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