Premium Motion Architecture
Flawless Dynamics.
Perfect Inertia Matching.
Same power, different character! The Estun EM3 servo motor family handles instantaneous acceleration with the low-inertia EM3A series and delivers rock-solid stability under heavy CNC loads with the high-inertia EM3G series. A broad range that fits every mechanical design.
23-Bit Absolute Encoder
Divides one revolution of the motor shaft into 8,388,608 increments. Ensures smooth, vibration-free operation at very low speeds and outstanding surface quality on CNC machine tools. Retains its position during power outages.
300% Peak Torque
During rapid acceleration and deceleration, it momentarily delivers up to 3 times its rated torque to overcome mechanical inertia. Eliminates stalling at start-up.
IP67 Harsh Environment Protection
The motor housing and all connectors (excluding the shaft end) are protected to IP67 against water and heavy dust. Fully resistant to oil leaks, cutting fluids and extremely dusty industrial environments.
A Family Shaped by Inertia
Choose "Low Inertia" where instantaneous acceleration is required, such as flying shears, and "High Inertia" where rock-solid stability under fluctuating loads is required, such as CNC. The Estun EM3 family offers a dedicated rotor design for every mechanical system.
EM3A Series
Its slim, elongated rotor keeps its own inertia to a minimum. It can accelerate and stop within milliseconds.
- Rated Speed: 3000 RPM
- Power Range: 50 W - 5 kW
- Ideal for: Packaging, robotics, pick-and-place, flying shears
EM3G Series
Its thick rotor creates a flywheel effect and absorbs mechanical fluctuations (resonance) itself when under load.
- Rated Speed: 1500 RPM
- Power Range: 850 W - 5 kW
- Ideal for: CNC machine tools, woodworking, winders
EM3J Series
A general-purpose model that balances speed and stability. The safest choice for versatile projects.
- Rated Speed: 3000 RPM
- Power Range: 50 W - 1 kW
- Ideal for: Conveyors, linear modules, general automation
EMB Series
For processes with massive power requirements. Its wide flange and heavy-duty bearings provide full resistance to severe mechanical stress.
- Rated Speed: 1500 RPM
- Power Range: 7.5 kW - 22 kW
- Ideal for: Metal bending, presses, large-axis transfers
Engineering Note: Inertia Matching
Why Isn't Power (kW) Alone Enough? The biggest mistake in machine design is selecting a motor by looking at power (kW) alone. The ratio between the load inertia reflected to the motor shaft ($J_L$) and the motor's own rotor inertia ($J_M$), known as the inertia ratio, determines controllability. In belt-and-pulley systems this ratio can be tolerated up to 10, whereas with precision ball screws it should be kept below 5.
Choosing EM3A vs EM3G: If you use a motor with a thick, heavy rotor on a packaging machine with rapid start-stop cycles, the motor spends its energy turning its own rotor (and heats up). That is why the slim-rotor EM3A (Low Inertia) is used. On a CNC machine tool with variable (resonant) loads, however, a slim-rotor motor lets the tool tip oscillate; here the heavy-rotor EM3G (High Inertia) should be selected to benefit from the flywheel effect.
Frequently Asked Questions
How does a 23-bit encoder differ from a standard 17-bit encoder?
While a 17-bit encoder divides one revolution into 131,072 increments, a 23-bit encoder divides it into a full 8,388,608 increments. This huge difference in resolution lets the motor rotate smoothly rather than "cogging/vibrating", especially at very low speeds such as 1-2 RPM. It is essential for laser cutting and high-resolution CNC applications.
What happens when the absolute encoder battery runs out?
The absolute encoders used in Estun motors keep tracking position thanks to their internal battery, even when the machine is switched off. When power is restored, the machine knows exactly where it is, so no "homing" is required. Before the battery runs out (typically after 3-5 years), the drive issues a "Low Battery" warning in advance. The position memory is not lost when the battery is replaced.
Can I submerge an IP67 motor in water?
The IP67 rating means the motor housing can withstand immersion in water at a depth of 1 metre for 30 minutes (with connectors fitted). However, the motor shaft (shaft exit) is not covered by this protection. If the environment involves heavy cutting fluid, oil spray or pressurised washdown, the shaft seal (oil seal) option must be ordered together with the motor.
Estun EM3 Series Servo Motors Resource Center
Commissioning software, parameter guides, fieldbus files and CAD data — securely downloadable from a single place.
Catalogs and Guides
Brochures for the Estun servo motor and drive product family.
Estun Motion Control Catalog
Technical data, speed-torque curves and selection guide for the Estun servo motor (EM3) and drive family.
ED3L Drive Manual
Installation, fault codes and parameter reference for the ED3L servo drive, compatible with EM3 series motors.
3D and 2D CAD Drawings
Mechanical dimension files for EM3A, EM3G, EM3J and EMB series motors for machine design.
EM3A Series Drawings
Mechanical CAD files for low-inertia EM3A motors.
EM3J Series Drawings
Mechanical CAD files for medium-inertia EM3J motors.
EM3G Series Drawings
Mechanical CAD files for high-inertia EM3G motors.
EMB Series Drawings
Mechanical CAD files for heavy-duty, high-torque EMB motors.
Let's Choose the Right Motor Together
Conveyor, CNC or press... Leave your project's mechanical calculations and inertia ratios to ONX Control engineers, and we will quote the ideal Estun combination for your machine.