6 kW 18000 RPM Spindle Motor ER32

Detailed Product Review

The GDZ120X103-6FIN model spindle motor, with its 6 kW power and 18000 RPM speed, functions as an electro-mechanical actuator in CNC machining centers, ensuring the high-speed and precise rotation of cutting tools. Powered by 380V three-phase AC, this motor offers variable speed control from 0-400 Hz via an integrated frequency converter (VFD). This wide speed range allows for the adjustment of optimal cutting parameters for different material types and cutting tool geometries, thereby maximizing material removal rates while optimizing surface quality and tool life. The 6 kW nominal power output is designed to provide the high torque and cutting force necessary for machining high-strength materials such as steel and titanium alloys. Its air-cooled design maintains thermal stability during continuous operation, extending bearing life and preventing performance degradation, which is critical for long-term, stable operations.

The mechanical structure of this spindle motor is engineered for high rigidity and precision. The ER32 collet system, used as the tool holding mechanism, ensures secure tool mounting with high clamping force and low runout for a wide range of tool diameters (typically from 2 mm to 20 mm). The spindle is supported by angular contact ball bearings capable of absorbing both radial and high axial loads. These bearings manage thermal expansion and dynamic loads even at high speeds, enhancing machining accuracy and repeatability. The motor’s compact physical dimensions, with a 120 mm diameter and 103 mm length, facilitate integration into CNC machines with limited mounting space, offering flexibility in machine design. Compliance with the industrial 380V voltage standard ensures seamless adaptation to existing industrial infrastructures, providing a wide range of applications in sectors requiring high precision, such as metalworking, mold making, aerospace, automotive, and composite material processing. Mermak has 16 years of experience supplying high-quality industrial automation parts to clients in the United Kingdom, United States, Canada, Australia, Ireland, New Zealand, South Africa, and similar international markets.

Machining Capacity with High Power and Wide Speed Range: The 6 kW continuous power output provides the necessary torque for high material removal rates and deep cuts, especially in demanding materials like high-alloy steels or hardened tool steels. The 0-18000 RPM speed range allows for both roughing operations requiring high torque at low speeds with large diameter tools, and fine machining and surface finishing applications at high speeds with small diameter tools. This broad operational spectrum enables the application of different machining strategies with a single spindle motor, increasing production flexibility and optimizing cycle times.

Tool Holding Rigidity and Versatility with ER32 Collet System: The ER32 collet system, designed according to DIN 6499 standards, offers a wide tool holding diameter range from 2 mm to 20 mm. This system guarantees the secure clamping of the cutting tool with minimal runout (typically below 5 microns) relative to the spindle axis, due to the high radial clamping force provided by the collet’s conical structure and clamping nut. The high clamping force prevents tool slippage or vibration during cutting operations, improving machining accuracy and extending tool life. This versatility allows a wide range of cutting tools for different machining tasks to be used on a single spindle.

Operational Stability with Angular Contact Bearings and Efficient Air Cooling: The angular contact ball bearings used in the spindle are capable of simultaneously carrying both high radial and axial loads. These bearings are mounted with a specific preload to increase the spindle’s dynamic rigidity and minimize vibrations at high speeds, which is critical for machining accuracy. The air cooling system dissipates heat generated in the motor’s stator and rotor windings directly to the outside, maintaining the motor’s operating temperature at optimal levels. This thermal management extends the life of the bearings and winding insulation, reduces dimensional changes due to thermal expansion, and ensures the motor’s long-term, uninterrupted, and stable performance while eliminating the need for an external coolant circuit. Our products are stocked at our Ankara Uzay Sanayi factory/warehouse, ensuring up-to-date stock quantities and prices on our website. Stocked products are prepared from the warehouse without production waiting times.

Technical Specifications and Capacity

Technical Frequently Asked Questions (FAQ)

What technical parameters should be considered when selecting a suitable frequency converter (VFD) for this spindle motor?

VFD selection is directly related to the spindle motor’s nominal power (6 kW), nominal current (12.6 A), maximum frequency (400 Hz), and supply voltage (380V). It is recommended that the selected VFD have a power capacity at least 10-20% higher than the motor’s nominal power to ensure stability during sudden load changes. Additionally, the VFD’s output frequency range should cover 0-400 Hz, and support for advanced control modes such as Sensorless Vector Control (SVC) or Closed-Loop Vector Control (FVC) is critical for high torque and precise speed control even at low speeds. Adjustable acceleration/deceleration ramps minimize dynamic stresses on the tool and workpiece. Overcurrent, overvoltage, undervoltage, and overheat protection functions enhance system safety and extend motor life.

What is the technical contribution of angular contact ball bearings to spindle performance and lifespan, and what are their maintenance requirements?

Angular contact ball bearings enable the spindle to carry both radial and axial loads with high rigidity. These bearings are typically mounted in pairs or sets with a specific preload. Preload eliminates the clearance between the inner and outer races of the bearings, increasing the spindle’s dynamic rigidity, reducing vibration, and minimizing tool runout even at high speeds. This directly affects machining accuracy and surface quality. Furthermore, the design of these bearings is more resistant to centrifugal forces generated at high speeds and has the capacity to manage thermal expansion. For maintenance, these types of bearings usually come lubricated for life and equipped with sealing gaskets. However, bearing life can be shortened in cases of overload, high temperatures, or contamination. Periodic vibration analysis and temperature monitoring of the spindle motor are important for detecting potential bearing failures in advance.

What engineering principles are applied for the thermal management and environmental integration of an air-cooled spindle motor?

Thermal management in air-cooled spindle motors is based on the principle of an integrated fan on the motor housing drawing airflow through or over the motor to dissipate heat. This system is preferred in applications where the complexity of water-cooled systems is to be avoided. During integration, ensuring that airflow around the motor is not obstructed and adequate ventilation is provided is critical. Increased temperature inside the CNC machine enclosure can reduce the motor’s cooling efficiency, so internal air circulation and exhaust fans should be considered. Additionally, air-cooled systems can be more susceptible to dust and particles in the environment. Therefore, using appropriate filtration systems at the motor’s air intake points prevents contamination and wear of internal components, extending motor life. Ambient temperature and humidity levels are also factors affecting the motor’s thermal performance and should be considered during the design phase.

What are the optimal tool diameter and material machining capabilities of this spindle motor with the ER32 collet system?

The ER32 collet system is generally capable of securely holding tool diameters ranging from 2 mm to 20 mm. With a 6 kW power output and an 18000 RPM speed range, this spindle enables effective machining across a wide spectrum of materials. High speeds are ideal for processing softer materials like aluminum, brass, plastics, and composites at high cutting speeds, resulting in smooth surface finishes and rapid material removal rates. High-speed machining of hardened steels or engraving applications with small diameter carbide tools (e.g., 3-6 mm) are also possible, but feed rates and depth of cut must be carefully adjusted. The 6 kW power provides sufficient torque for deeper cuts and higher feed rates in harder materials such as stainless steel or medium-carbon steel with larger diameter tools (e.g., 10-20 mm). Tool material (HSS, carbide), coating, and geometry should be selected in accordance with the hardness of the material to be machined and the desired surface finish. Mermak ensures careful packaging, invoice/document follow-up, and works with reliable logistics partners. The shipment process is closely monitored by the Mermak team. Product videos and factory viewings are available via WhatsApp or our contact channels upon request.