UK-based Saietta Group is in the final stages of commercializing its axial flux motor technology, having spent the last two years ensuring the IP surrounding its motor designs is secure. Previously, the company has produced entire electric motorcycles, however its focus under the direction of Wicher Kist, CEO since 2017, is now firmly on motor rather than complete vehicle supply.
Notably, it is targeting the low-cost end of the powertrain spectrum, with one of its initial offerings, developed as an electric replacement for 125cc motorcycle engines, which runs at 60V. Currently, the company is scaling up to produce 100,000 units per annum and is looking to the Indian market, which it feels is ripe for electric adoption.
Saietta’s motor designs are of the axial flux type, but are unique on the market as they combine features of both a yoked stator AFM using distributed windings and a yokeless stator AFM with concentrated windings. This can be best described as a yokeless stator with a distributed winding and, significantly, the company has developed the design to use low-cost core materials, which can be assembled using an automated process.
What prompted the move away from motorcycle production?
I stopped all motorcycle development because I know how difficult it is to develop a full vehicle, but what I recognized at Saietta was that from a powertrain perspective, we needed to create an axial flux motor, that was the right performance, for the right price, for the right market.
What are Saietta’s key strengths in a rapidly growing electric motor market?
If you recognize axial flux as one of the more efficient motor topologies, then there are effectively only two groups. The first is a yoked stator with distributed windings, the second, a yokeless stator with concentrated windings. The first is inherently expensive to make, because you have the copper splits, and the spinning disk in the middle. It has some benefits – for example, you can cool the end plates. But with that topology you can never get down to the price that we can achieve with ours. Then, if you look at the typical yokeless configuration, they tend to use bobbins with the copper wound around them, and again, that is expensive to produce. What we have done is combine the best of both worlds.
We have managed to create a motor structure out of the copper [stator] coils, into which we can slide the laminations, like we used to do with DC motors. The whole thing then sits in a very clever extruded stator ring. Because we work with discrete coils, they can come down a conveyor belt and we can fully automate the assembly of the stator ring.
Also, in terms of magnets, we do not need segmentation, so we don’t have to slice the magnets into tiny slices and then glue them back together. This saves lots of money on the magnet side, and then of course the rotor is mild steel.
We are also extremely strong on the simulation side. If you’re a client and you have a vehicle requirement, we can translate that into a motor design and create an efficiency map before even making the motor. We can run it over a cycle through the efficiency map and then calculate the energy consumption over that cycle before having to put money into prototyping.
How flexible is the AFT design?
We are working on our own integrated controller and cooling system, which means we can then reduce the number of components in the overall system. However, we can work with standard controllers as well, which allows us to build prototype vehicles very quickly.
How did you settle on Asia as an initial target market?
Over my 25-year career I’ve learned that it’s always good to start with legislation. So we started with the roadblocks and legislation and did a market prediction out of that.
I’m just a powertrain specialist and a product developer, but I traveled to India a lot over the past few years, until early February this year. What I was amazed at was the number of two-wheelers. People are using two-wheelers as proper commuter tools. I started looking at the motorcycles themselves. You quickly conclude that they are dirt cheap, and they’re all about 110cc, which in my world translates to 11kW.
This raised the question of why are there no 110cc electric motorcycles yet? It’s because the vehicle developers are also mainly in China. In that market, they tend to just have a single person on a bike so they can get to work. But in India they put a dog and the wife and three kids on a bike. So 4kW [the general power of most small electric motorcycles] is not enough.
Nobody has yet been able to create a solution of combining swappable batteries with an ultra-efficient but also ultra-affordable electric motor. That’s the nuts that I wanted to crack and I think we are there. If you consider that this particular motorcycle market is potentially 100-150 million units per year within the next five years, the demand is going to explode.
