CubeMars AKE40-6 KV90

The AKE40-6 KV90 is a quasi-direct drive actuator that combines a brushless motor with a low ratio 6:1 planetary gearbox. With a housing 51 mm in diameter and 24.5 mm thick, it weighs only 140 g yet produces 5.5 Nm peak torque. It is designed for exoskeletons and lightweight robot joints where both weight and motion quality matter.

Key features

• High torque density. 5.5 Nm peak torque from 140 g, a torque density of 39.3 Nm/kg.
• Low backlash. Gearbox backlash is limited to 9 arcminutes, about 0.15 degrees.
• Very low backdrive torque. Backdrive torque is only 0.05 Nm. It follows human motion easily and provides a solid mechanical basis for active compliance control.
• Quasi-direct drive. The low ratio gearbox combines the torque transparency of direct drive with the torque density of a servo actuator.
• Quiet operation. Optimized gearbox components reduce noise and improve durability.

Applications

Typical uses include knee, hip and elbow assist exoskeletons, wearable rehabilitation devices, lightweight robot joints that interact with people, and research on torque sensing compliant control.

Is it enough for your project?

The AKE40-6 delivers 1.8 Nm continuous and 5.5 Nm peak torque. For example, a 0.5 kg load at the end of a 30 cm arm needs about 1.5 Nm of static torque (0.5 × 9.81 × 0.30). That load stays within the actuator's rated torque.

It runs on 24 V, with a rated speed of 260 rpm and a no-load speed of 330 rpm. In the manufacturer's temperature rise test it ran at 260 rpm at 1.5 Nm and 206 rpm at 2.5 Nm. The output bearing has a dynamic load rating of 1,040 N and a static load rating of 730 N.

How it compares to similar models

• AKE60-8 KV80. The larger model in the same family. With an 8:1 reduction it gives 5 Nm rated and 12.5 Nm peak torque, weighs 260 g and measures Ø69 × 25 mm.
• AKE50-8 KV110. With an 8:1 reduction it gives 2.5 Nm rated and 7.5 Nm peak torque, weighs 190 g and is thinner at 22.5 mm.
• AK40-10 V3.0 KV170. A similar weight class, but with the driver board and dual encoders integrated in the housing. With a 10:1 reduction it gives 4.1 Nm peak torque and weighs 190 g.

Frequently asked questions

Is the driver included?

No. The AKE40-6 consists of the motor and planetary gearbox and has no driver board. The box includes a φ6 x 2.5 mm sensor magnet for an external encoder. Our team can help you choose a driver and encoder for your project.

What does quasi-direct drive mean?

The motor is used with a low ratio gearbox instead of a high reduction. Torque can then be estimated directly from motor current, the joint yields easily to external forces and it tolerates impacts better.

Can it be turned by hand?

Yes, very easily. Backdrive torque is 0.05 Nm, which is why it does not resist the user's movement in exoskeletons.

How loud is it?

According to the manufacturer's measurement, 65 dB at 65 cm from the motor.

In the box

• AKE40-6 KV90 quasi-direct drive actuator
• φ6 x 2.5 mm sensor magnet

Box size 140 x 137 x 77 mm.

Related products

Our team can help you choose a driver, encoder and mounting solution.

Products in stock are dispatched within 3 business days from our warehouse in Turkey.

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