C.F Motor

World's first Circumferential Flux Motor

Under Development


Today's Problem

Future UAV capability is defined by two technologies: the efficiency of propulsion system and the energy density of batteries. Today's core laminated brushless motors do not scale and high power, larger motors typically run hot, becoming so inefficient active external cooling is required. When left uncooled they are inoperable in harsh temperate climates. 

Tomorrow's Solution

At Motion-Robotics we have developed a revolutionary motor architecture to break through this technology ceiling. Our patented, trapezoidal wound coils - fabricated in house -  results in drastically improved passive cooling, eliminating active cooling requirements. By virtue of our core-less design we experience no losses across laminations and carry none of their added mass, meaning we are both weight and energy efficient.

Our C.F Motor is the innovation in electric motors that has been needed since 1837.  




The future of robotics relies upon advances in actuator design, sensors, battery power technologies, AI methods and material science.

The Circumferential Flux motor represents an important advance in electric motor design. Motion Robotics has developed the motor to achieve demanding torque, power and efficiency critically required by all types of electric vehicle and drone.

Axial Motor

Radial Motor

Unlike the radial and axial motors the permanent magnets do not pass the energizing coils in a sideways fashion, instead the magnets fly through the coils, like a circumferential solenoid.

What's different?

There is no lamination required, so the motor is significantly lighter, has zero eddy current loses, zero cogging, is cheaper to build and the coil inductance is very low. The maximum power factor is naturally close to 1, implying maximum power factor efficiency.

Lighter, cheaper and more efficient
Passively cooled 

The volume provided to the coil area allows much more copper to be wound, allowing the coil winding resistance to be as low as 0.005 ohms.


For a current of 100 amps, whereas a coil of 0.1 ohms will dissipate 1 Kilowatt of heat, our motor will dissipate 50 Watts, which is less than a household lamp. Whilst other motors’ heat generation must be cooled, adding to complexity in the motor, weight and cost, ours can be naturally air cooled like a household lamp.

Payload vs Range

Real-world performance

Don't believe us? We didn't at first either - so we've run and tested all of our motors on a thrust rig and an in-line dynamometer. We've recorded all our efficiencies with off the shelf propellors ranging up to 1.5m in diameter. We even built a flight path optimisation model that computationally projects accurate craft ranges based on our benchmarks. The results - speak for themselves!

Above results for a 10 KW motor/axis hexacopter of structural weight 5kg carrying 20 Kg batteries.



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