Electromate Inc., Canada’s exclusive distributor of maxon precision mechatronic components, announces the release of the HEJ 70 High-Efficiency Joint actuator. This compact, fully integrated robotic joint actuator is engineered to meet the demanding performance needs of mobile and manipulation robots.
The HEJ 70 48 50 actuator combines a torque-dense motor, planetary gearbox, 14-bit absolute encoder, and EtherCAT control electronics into a sealed, IP67-rated package. It delivers a peak torque of ±50 Nm and a maximum joint speed of 28 rad/s, with efficiencies up to 74% at 12 Nm and 26 rad/s. The actuator’s compact design (1.05 kg) and high performance make it suitable for lightweight robotic applications.

Key specifications include:
- Peak Torque: ±50 Nm (future variants may exceed 60 Nm)
- Max Joint Speed: 28 rad/sec @ 60 V; 22 rad/sec @ 48 V
- Efficiency: Up to 74% at 12 Nm and 26 rad/sec
- Ingress Protection: IP67 (sealed against dust and water)
- Voltage Range: 30–60 Vdc
- Control Interface: EtherCAT (daisy-chain), PWM fan control, 1 kHz cycle rate, PDO-mapped gains
- Position Sensor: 14-bit absolute encoder, < 0.6° error
- Torque Sensing: Current-based, ± 0.8 Nm accuracy
- Backdrive Torque: ~0.5 Nm
- Output Bearing: Cross-roller bearing
Performance and reliability
- Continuous Torque: ±19 Nm at 2 rad/sec without extra cooling
- Efficiency Peak: ~74% at 12 Nm & 26 rad/sec; generator efficiency reaches ~72%
- Designed for High Cycle Fatigue: 12 million impacts at 38 Nm, 100k at 50 Nm
- Operating Life Examples: Over 56,000 hours at 10 Nm, 22 rad/sec
The HEJ 70 actuator is ideal for uses in autonomous mobile manipulators and cobots, lightweight robotic arms and grippers, quadruped and biped robots, end-effector joints, compact SCARA joints, and wearable robotics.
It comes ready-to-use with onboard control electronics, torque & position sensing, and active cooling system, a simplified system architecture using EtherCAT daisy-chain which reduces external cabling, and includes simulation models for design verification and sizing.
The HEJ 70 High-Efficiency Joint actuator is available for quote in Canada through Electromate Inc. For more information or to request a quote, visit https://www.electromate.com/hej-70-high-efficiency-joint-for-mobile-robots/.
Filed Under: AUTOMATION, MOTION CONTROL, Robotics • robotic grippers • end effectors