General refurbished - warranty 12 months 

Heidenhain QSY 155B (ID 339 880-63) – Replacement Servo Motor for CNC Machines

The Heidenhain QSY 155B (ID 339 880-63) is a high-precision replacement servo motor designed for CNC machine operators who need a reliable, like-for-like substitute for a failed or worn-out axis motor. Engineered for seamless integration with Heidenhain drive systems, this motor ensures accurate positioning, stable torque delivery, and long-term performance in demanding industrial environments. If your machine has stopped due to servo errors, axis vibration, or encoder faults, the QSY 155B (ID 339 880-63) provides a direct OEM-compatible solution to restore full machine functionality with minimal downtime.

What Is the Heidenhain QSY 155B (ID 339 880-63) Servo Motor?

The Heidenhain QSY 155B (ID 339 880-63) is a high-performance AC servo motor designed for precise axis control in CNC machines and advanced automation systems. This motor is part of Heidenhain’s QSY series, known for delivering stable torque, accurate positioning, and reliable motion even under continuous industrial loads. The ID 339 880-63 refers to the specific configuration and electrical parameters of this motor, ensuring it matches the exact requirements of machines originally built with this model. It is commonly used as an X-, Y-, or Z-axis motor in milling, turning, and multi-axis machining centers equipped with Heidenhain control and drive technology.

Key Features of the Heidenhain QSY 155B (ID 339 880-63)

Discover the essential strengths of the Heidenhain QSY 155B (ID 339 880-63): a precision-engineered servo motor specifically built for CNC machine tool axes. Designed to seamlessly replace original equipment in Heidenhain-controlled systems, this motor delivers exceptional torque, high-speed performance, and durability in demanding industrial environments. Whether you're servicing a milling machine, turning center or automation line, the QSY 155B (ID 339 880-63) gives you the reliability and compatibility required to restore full functionality and maintain machining accuracy.

Exact OEM Replacement for Heidenhain Systems

The QSY 155B is part of the Heidenhain QSY series of synchronous motors designed for CNC feed-drives and axis motors. The ID number (339 880-63) identifies the exact configuration, ensuring compatibility with machines originally built with this motor.

High Precision Motion & Encoder Integration

These motors support integrated absolute rotary encoders (for example the EQN 1325) which provide precise position feedback, helping maintain accurate axis movement and reducing errors. This is especially important for CNC machines needing repeatable, high-accuracy motion.

Strong Torque and Performance Ratings

 From available specification tables for the QSY 155 series:

• The QSY 155B version lists a rated torque around ~9.2 Nm (without encoder) and a stall torque of ~13 Nm in one configuration.

• Maximum torque for this series is up to ~39 Nm (for QSY 155B) according to one table. This ensures the motor can handle demanding feed or axis loads in CNC machining.
  
  

High Speed Capability (3000 rpm rated in many cases)

The QSY 155B family is rated for 3000 min⁻¹ (rpm) in many configurations. This makes it suitable for high-speed axis movement and modern machine tool applications.

Robust Industrial Construction

These motors are built for industrial usage in CNC machine tools:

• They are designed for continuous operation (machine tool feed drives)

• They include features such as low torque ripple, good inertia matching for axis drives, and durable bearings.

• Protection ratings: for example, motors in QSY series are rated motor IP65 and shaft exit IP64 in some materials.
  
  

Integrated Diagnostic/ID Labeling Features

In some versions (with absolute encoders), an electronic ID label is included which allows the CNC controller or diagnostic software to identify the motor type and parameters automatically. This simplifies commissioning, spare-part identification and aftermarket replacements.

Compatibility with Heidenhain Drives & Controls

The motor is part of the ecosystem designed by Heidenhain for feed drives and axis motion; using a motor from the same manufacturer reduces integration issues (drive tuning, encoder feedback, matching inertia). For machine owners replacing this motor, that means fewer surprises and a more “plug-in” replacement experience when it matches the original spec (ID 339 880-63).

Broad Application in CNC Machines & Automation

While your machine may not list every spec, the QSY 155B is commonly used in milling machines, turning centres, automation axes, and retrofits when the original axis motor fails and the machine uses Heidenhain control hardware. The general QSY series brochure says the motors are for “axis and spindle drives” in numerically controlled machine tools.

Technical Specifications – Heidenhain QSY 155B (ID 339 880-63)

• Model: Heidenhain QSY 155B

• ID Number: 339 880-63

• Rated Speed: 3000 rpm

• Rated Torque: approx. 9.2 Nm

• Stall / Starting Torque: approx. 13 Nm

• Maximum Torque: up to approx. 39 Nm

• Rated Voltage: approx. 295 V

• Motor Weight: approx. 15 kg

• Rotor Inertia: approx. 33 kg·cm²

• Encoder Compatibility: EQN 1325 absolute encoder (depending on configuration)

• Brake Option: Variants available with or without 24V DC holding brake

• Motor Series: QSY synchronous AC servo motor family

• Application: CNC machine feed-axis / positioning motor

• Operating Mode: Continuous industrial operation

• Cooling: Natural convection (standard for QSY series)

Common Use Cases – Where the Heidenhain QSY 155B (ID 339 880-63)

The Heidenhain QSY 155B (ID 339 880-63) servo motor is commonly installed as a feed-axis drive in high-precision CNC machines that require stable torque, accurate position control, and reliable performance under continuous industrial loads. Typical applications include X-, Y- or Z-axis motion on milling machines, turning centers, machining centers, and multi-axis automation systems equipped with Heidenhain control and drive technology.

Below are the most frequent use cases operators search for when replacing this motor:

• CNC Milling Machines: used for linear axis control in 3-, 4-, and 5-axis milling machines where high positional accuracy and smooth feed motion are required.

• CNC Turning Centers / Lathes: installed on carriage, turret, or cross-slide axes to ensure precise feed rates and repeatable tool positioning.

• Vertical and Horizontal Machining Centers: provides stable feed motion during heavy-duty cutting and fast traverse movements.

• Automation & Robotic Positioning Axes: functions as a servo drive in automated production cells requiring precise, repeatable linear movement.

• Retrofit and Machine Rebuild Projects: frequently used to replace worn or obsolete motors in older CNC machines originally built with Heidenhain drive systems.

• Machine Axes Showing Servo Faults or Encoder Errors: commonly replaced when operators experience issues such as axis vibration, positioning errors, increased backlash, abnormal noise, or “servo alarm” messages.

Compatibility Guide – How to Know if QSY 155B (ID 339 880-63) Fits Your Machine

To confirm that the Heidenhain QSY 155B (ID 339 880-63) is the correct replacement for your CNC machine, check these key points:

• Match the ID number: the number on your old motor’s nameplate must match 339 880-63 or follow the same configuration pattern.

• Verify encoder type: ensure your machine uses the same feedback system (e.g., EQN or ERN encoder) as the replacement motor.

• Check mounting and shaft dimensions: compare flange size, bolt pattern, and shaft type with your existing motor to ensure mechanical compatibility.

• Confirm voltage and drive compatibility: your CNC drive module must support the electrical specs of the QSY 155B model.

• Brake option: if your existing motor has a holding brake, the replacement must include the same feature.

If these parameters match, the QSY 155B (ID 339 880-63) will fit your machine without modification.

Symptoms Indicating You Need a New QSY 155B (ID 339 880-63)

If your CNC machine uses the Heidenhain QSY 155B (ID 339 880-63) and you notice any of the following issues, the servo motor may be failing and require replacement:

• Axis servo alarms or fault messages during machine startup or movement

• Irregular or jerky axis motion, vibration, or oscillation

• Loss of positioning accuracy, drifting, or repeatability errors

• Overheating of the motor housing even at low load

• Unusual noises such as grinding, humming, or bearing rumble

• Encoder errors, feedback faults, or “position control error” warnings

• Axis stops unexpectedly or refuses to move under load

• Slow response or weak torque, especially during rapid feed or acceleration

• Visible damage to connectors, cables, or insulation on the motor
  
  

If one or more symptoms appear, it’s often a sign that the QSY 155B motor is worn, electrically compromised, or suffering from encoder or bearing failure—and replacing it with the correct ID 339 880-63 variant will restore stable machine performance.

Why Choose the Heidenhain QSY 155B (ID 339 880-63) Replacement Motor

Choosing the Heidenhain QSY 155B (ID 339 880-63) as a replacement ensures your CNC machine receives the exact performance, precision, and reliability it was originally designed for. This motor is built to deliver stable torque, accurate positioning, and smooth axis movement under demanding industrial conditions. Because it matches the OEM specifications—including encoder type, electrical parameters, and mechanical dimensions—it integrates seamlessly with your existing Heidenhain drive system without requiring modifications or retuning.

Machine operators rely on this model because it restores full axis performance, eliminates servo alarms, and maintains the machining accuracy expected from professional CNC equipment. For users who need fast recovery from downtime, the QSY 155B (ID 339 880-63) is the most reliable, plug-compatible solution available.

FAQ – Heidenhain QSY 155B (ID 339 880-63)

What is the Heidenhain QSY 155B (ID 339 880-63) used for?

It is a high-precision servo motor used for feed-axis control in CNC milling machines, turning centers, machining centers, and automation systems equipped with Heidenhain drives.

How do I know if this motor is compatible with my CNC machine?

Check the ID number on your old motor’s nameplate. If it matches 339 880-63 or shares the same configuration, it is typically a direct replacement. Also verify encoder type, shaft size, and brake option.

Can the QSY 155B replace older or different QSY models?

Yes, in some cases—but only if electrical specs, mechanical dimensions, and encoder compatibility match. Always compare the ID numbers to ensure proper configuration.

Does this motor come with an encoder?

Most QSY 155B units come equipped with a Heidenhain absolute encoder (e.g., EQN series), but this depends on the specific ID variant. Always confirm the encoder type before installation.

Can I use a QSY 155C or QSY 155D instead of the QSY 155B?

They may be suitable alternatives, but torque, mounting, and encoder specifications differ. A direct replacement should ideally match QSY 155B and the exact ID number.

What are common signs that my QSY 155B needs replacement?

Servo alarms, axis vibration, encoder faults, overheating, irregular motion, loss of accuracy, or unusual noise.

Does the motor require drive tuning after installation?

In most cases, no—if it’s the correct ID number, the drive recognizes its parameters. If an alternate model is used, tuning may be required.

Can this motor be repaired instead of replaced?

Yes, many service centers offer encoder replacement, bearing rebuilds, insulation testing, and complete overhauls. However, severe encoder or winding damage often makes replacement more cost-effective.

Summary – Why the QSY 155B (ID 339 880-63) Is the Right Choice

The Heidenhain QSY 155B (ID 339 880-63) is the ideal replacement for restoring full precision and reliability to your CNC machine. As an exact OEM-matched servo motor, it ensures perfect compatibility with Heidenhain drives, correct encoder feedback, and consistent torque performance under demanding industrial workloads. Choosing the correct ID-specific variant eliminates integration issues, reduces downtime, and maintains the machining accuracy your system was originally designed to deliver. For operators seeking a dependable, plug-compatible solution, the QSY 155B (ID 339 880-63) provides the most reliable and efficient path back to full machine operation.