The editorial explicitly argues the headline is not the physics but the production engineering: solving stator delamination, rotor eccentricity, and yield-curve economics at scale. Mercedes isn't first to ship axial flux in a car, but is the first major OEM to claim large-scale series production, which is a categorically different feat than low-volume hypercar runs from Koenigsegg or Ferrari.
Mercedes touts roughly 3x the power density and one-third the axial length of an equivalent radial flux motor, enabling the YASA-designed disc-shaped unit to mount inboard of the wheel hub. The company is committing the Berlin-Marienfelde plant — its century-old combustion engine site — to series production for the AMG.EA platform launching in 2026, signaling confidence that the topology advantage justifies retooling a legacy facility.
By submitting the Mercedes announcement and driving it to 220 points, the submitter signals the HN technical audience views this as a substantive engineering milestone rather than a marketing release. The story's traction reflects interest in axial flux as a genuine architectural shift in EV powertrains.
The editorial frames YASA's segmented armature with PCB-style copper windings as the differentiated IP that makes volume production viable, contrasting it with the wound coils of conventional radial flux lines. The five-year gap between acquisition and series production reflects the real engineering work required to industrialize a topology that competitors have only fielded in hypercar volumes.
Mercedes-Benz announced large-scale series production of an electric axial flux motor at its Berlin-Marienfelde plant — the same site that built combustion engines for over a century. The motor is developed by YASA, the Oxford University spinout Mercedes acquired in 2021, and will debut in vehicles built on the AMG.EA electric platform launching in 2026.
The specs Mercedes is willing to put in print: roughly 3x the power density of an equivalent radial flux motor, and one-third the axial length. In automotive packaging terms, that translates to a motor disc thin enough to mount directly inboard of the wheel hub, freeing up cabin space, lowering the center of gravity, or — more interestingly for performance EVs — allowing multiple motors per axle without the usual driveline gymnastics. YASA's design uses a segmented armature with printed-circuit-board-style copper windings rather than the wound coils that dominate radial flux production lines.
The headline is not the physics. Axial flux motors have been understood since the 1830s. The headline is that someone finally figured out how to build them at automotive volume without the stator delaminating, the rotor going eccentric, or the yield curve collapsing the unit economics. Mercedes is not the first to ship an axial flux motor in a car — Koenigsegg, Ferrari, and Lamborghini have used YASA-derived units in low-volume hypercars. But "large-scale series production" at a legacy German OEM is a different category of claim, and Mercedes is the first major automaker to make it.
For twenty years the EV motor conversation has been a two-axis fight: permanent magnet vs. induction, and rare-earth vs. rare-earth-free. Topology — the actual geometry of how flux moves through the machine — has been treated as a solved problem. It is not.
In a conventional radial flux motor (which is every motor in your Model 3, your Taycan, your Ioniq 6), magnetic flux travels radially outward from rotor to stator, perpendicular to the shaft. The motor is shaped like a tin can — long axially, narrow in diameter — because you need length to wrap enough copper around the stator teeth to make useful torque. In an axial flux motor, the rotor and stator are parallel discs, and flux travels axially along the shaft direction. The motor is shaped like a pancake — wide in diameter, very short axially. For the same torque, an axial flux machine uses dramatically less iron and copper, runs cooler because the active surface area scales with disc area rather than cylinder circumference, and packages into spaces a radial motor physically cannot fit.
The trade-off, until now, has been manufacturability. Axial flux stators are not a stack of laminations you can punch out and press together — they are a printed or wound disc that has to maintain micron-level air-gap tolerances against a rotor disc spinning at 15,000+ RPM, with magnetic attraction forces trying to pull the two discs together at all times. Get the air gap wrong and you either grind the rotor into the stator or lose efficiency to a gap that's too wide. YASA's specific innovation — the one that got Mercedes to write a nine-figure check in 2021 — is a yokeless and segmented armature design that decouples the stator segments from each other, dramatically simplifying both manufacture and thermal management.
The community reaction on Hacker News (220 points, top of front page) split predictably. The EV engineers focused on the power density number and what it unlocks for in-wheel and hub-adjacent drive configurations. The skeptics focused on the absence of cost figures, warranty data, or any signal about NVH (noise/vibration/harshness) at scale — all three of which have historically been where exotic motor topologies die in production. One commenter noted that Renault and Stellantis have both publicly demoed axial flux prototypes and chosen not to productize, which is either a sign that Mercedes has cracked something they haven't, or a sign that Mercedes is about to learn an expensive lesson.
The deeper signal is what "made in Berlin-Marienfelde" means. Mercedes is converting a combustion engine plant — tooling, workforce, supply chain — into an axial flux line. That is a real capital commitment, not a marketing demonstrator. When a German automaker pivots a legacy plant, the bet is measured in decades and billions, not press releases.
If you don't work in automotive, the immediate implication is zero — your EV is still going to ship with a radial flux motor for the next 3-5 years minimum. But for anyone building adjacent hardware — robotics, drones, industrial actuators, e-VTOL, marine propulsion — axial flux just got a serious validation event. YASA was already selling motors into aerospace and marine; Mercedes scaling the manufacturing process will pull down unit costs across the entire supply chain, which means the same topology becomes economical for sub-automotive volumes.
For robotics specifically, the geometry matters more than the efficiency. A pancake-shaped motor that delivers 50kW in the package envelope of a dinner plate is the kind of thing that makes humanoid hip and shoulder joints feasible without exotic harmonic drives. Several robotics startups have been running custom axial flux designs (Boston Dynamics' Atlas hip actuator is rumored to be axial flux, though they haven't confirmed). A commodity automotive-grade unit at automotive prices changes the BOM math.
For anyone watching the rare-earth supply story: YASA's design still uses neodymium magnets. It is not a rare-earth-free play. The packaging win does mean less magnet material per kilowatt, which softens the rare-earth exposure curve but doesn't eliminate it. If you were hoping axial flux was a path around Chinese magnet supply, it isn't — at least not in this generation.
The interesting question is not whether axial flux works — Mercedes just answered that with a production line — but whether the manufacturing learning curve is steep enough that Tesla, BMW, Hyundai-Kia, and BYD all have working axial flux programs by 2028. Tesla's drive unit team has been quiet about topology for two years, which is either nothing or everything. BYD has the volume and the vertical integration to copy the process within 18 months of seeing it work. The next 24 months will determine whether "axial flux" becomes a footnote on the Mercedes spec sheet or the dominant topology for the second wave of EV powertrains. Either way, the textbook answer that EV motors are a solved problem just got rewritten in production, in Berlin, at scale.
It would have been awesome if that article had, at any point, explained what an electric axial flux motor was, and why anyone might want one.
Very cool. Good to see more axial flux motors in the wild - will be interesting to see if they become the new standard in future. With smaller material costs the cost to manufacture at scale could actually become lower than radialI expect radial will still dominate for at least another decade or so
I remember when YASA announced it and when MB bought them. Amazing technology and advancement in electric motor design. Good to see they somehow try to commercialize it.
I know what a "motor" is and I know what "electric" means but I have no idea what an "electric axial flux motor" is. I'm pretty sure it's not what Doc Brown used to travel through time but it could be.About once a week I think I'm too dumb to be on this s
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Mercedes acquired Yasa (UK) couple of years ago and now getting up to the speed in the production.Here is a nice video that explains axial flux motors with a factory visithttps://youtu.be/B2Hl4c1iZK0?si=VfDYARyuaPVj1nKmThey are so, so, small.