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Discussion Starter · #1 ·
Lucid has said little about the technology of the Air motors but, due to their very high power density, my brother had begun to suspect that they might be an axial flux design. The less efficient radial flux design dominates in EV applications, but there have been some indications that EV manufacturers were starting to look at axial flux designs for EVs, particularly with the growing interest in hub motors. As far as we could find, though, none had not made it to market.

We had both pored over the exploded view of the drive unit on the Lucid website and concluded, based on visible geometry, that they were the more conventional radial flux design. But there were still some aspects of the motor's performance that seemed to comport more with an axial design.

"Car & Driver" just published a review of the Dream claiming that Lucid does, in fact, use axial flux motors:


The relevant passage is:

"The axial-flux front and rear motors are identical, and each weighs a mere 163 pounds. They're a big part of how Lucid managed to get S-class space into a car with a 116.5-inch wheelbase . . . ."

(The article also answered a question that has been the subject of speculation on the Lucid forums: each of the 22 battery modules weighs 51.8 pounds, for a total of 1140 pounds of battery pack.)
 

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The motor shown in Lucid's animated illustration is not axial flux but given the performance and size I have long wondered if the illustration was misdirection. Lucid plays its cards fairly close to its chest.
 

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Discussion Starter · #3 ·
The motor shown in Lucid's animated illustration is not axial flux but given the performance and size I have long wondered if the illustration was misdirection. Lucid plays its cards fairly close to its chest.
That's what my brother and I are thinking. Mentioning something as arcane as axial flux motors in a car review does not strike me as something "Car & Driver" would have brought up unless they had specific information.
 

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I'm not an engineer, so the differences between radial and axial flux motors is completely lost on me. But isn't the battery in a car with such motors called a flux capacitor?

I don't think Lucid would mislead on the design of its motors, especially since models are on display in their studios. But perhaps they've succeeded in making some kind of a hybrid between radial and axial flux motors?

I wonder about the trade-offs Lucid is making by having such a power-dense, miniaturized motor. Would there be differences in terms of reliability or longevity? And why haven't other EV makers pursued this strategy? I can't believe such an approach is all benefit without cost.

I have similar questions about Lucid's 900V system. Why haven't other EV makers (except Porsche and Hyundai) opted for high voltage systems? The benefits, such as reduced charging time, seem obvious, but are there downsides?
 

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I'm not an engineer, so the differences between radial and axial flux motors is completely lost on me. But isn't the battery in a car with such motors called a flux capacitor?

I don't think Lucid would mislead on the design of its motors, especially since models are on display in their studios. But perhaps they've succeeded in making some kind of a hybrid between radial and axial flux motors?

I wonder about the trade-offs Lucid is making by having such a power-dense, miniaturized motor. Would there be differences in terms of reliability or longevity? And why haven't other EV makers pursued this strategy? I can't believe such an approach is all benefit without cost.

I have similar questions about Lucid's 900V system. Why haven't other EV makers (except Porsche and Hyundai) opted for high voltage systems? The benefits, such as reduced charging time, seem obvious, but are there downsides?
A "Flux capacitor" is a fictional item.

Most companies somewhat obscure some technical details of products they develop internally for competitive reasons. Certainly all the hard core engineering information we have about Tesla drive units comes from reverse engineering by outside parties.

Good questions about longevity and reliability. I find it encouraging that Atieva, the company that became Lucid, started life as an engineering venture specifically focused on developing EV drive components. Motor design is at the very core of Lucid.

The power of electric motors is measured in kilowatts (1 kilowatt = 1.34hp). Watts = Voltage X Amperage. A device designed to use twice the voltage will use half the amperage to make the same power. It is the amperage flowing through a wire, motor, or battery that generates waste heat. Using a 900V system will generate less heat than a 400V system of the same wattage. This allows the 900V system to use smaller lighter conductors and components as a general rule. Mercedes is also using a high voltage system, at least in the EQS. It is very likely that 800+ volt systems will be on the majority of new EVs designed in the future.

Why isn't everyone using the higher voltage batteries? Likely because of component availability 10+ years ago when this all started, but that's just a guess. High voltage high power chargers are now common in Europe and on the Electrify America network. I wonder if Tesla's V3 Superchargers are 8-900V capable for likely future projects. If not that locks Tesla in to the older technology until they can be upgraded.
 

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Good points on the 900V system. It sounds more like it’s an advantage that represents progress in EV engineering.

Peter Rawlinson had mentioned in a video a few months that Lucid eventually intends to market its technology to OEMs. If that includes the motor, I hope that eventually we will get full details of how they’ve achieved efficiencies no one else has been capable of.

Actually, on that note, Aptera claims to get 10 miles per kWH for a maximum of 1000 miles on a 100kWH battery pack and says its efficiencies are mainly due to aerodynamics with a drag coefficient of 0.13. So, motor efficiency helps but aerodynamics plays a larger role?

While looking into axial flux motors, I saw that Mercedes had acquired YASA, an axial flux motor start-up. The efficiency race is on.

By the way, I know a guy who has a flux capacitor in his DeLorean. It requires 1.21GW to activate though.

 
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