Electric vehicles, whether or not they’re vehicles on the street or electric vertical take-off and landing (eVTOL) plane, are constructed round related electric motors. However there are very important variations together with part prices, mass, and redundancy.
Jon Wagner spent 5 years because the senior director of battery engineering for Tesla earlier than becoming a member of California-based eVTOL developer Joby Aviation in 2017. He spoke with IEEE Spectrum about how engineering differs between vehicles and plane.
How do eVTOL motors differ from automotive motors?
Jon Wagner: Typically, floor transportation has a distinct deal with value versus mass. You already know, would you be prepared to spend extra on the components as a way to save a certain quantity of mass? The trade-offs finish on the bottom car and at a sure level the fee is dominant, whereas with aviation, the trade-offs between value and mass go lots deeper. And so for sure options eVTOL makers are prepared to spend extra money as a way to allow both lighter weight or higher effectivity.
The opposite key distinction is said to security. In essence, we’re coping with the identical motor applied sciences for floor transportation and aviation proper now, so the failure modes are related. However after all, with aviation now we have the will for continued secure flight and touchdown, and that drives what you do within the design to mitigate these failures in the event that they have been to happen. In lots of instances in floor transportation, the mitigation for a failure is to tug over safely to the facet of the street. In aviation, the mitigation is redundancy, as a result of there’s not an choice to tug over.
Is redundancy designed into EV motors?
Wagner: Usually, redundancy just isn’t designed into electric vehicle drive systems solely for the aim of redundancy. There are some vehicles now which have all-wheel drive—so there’s a motor on the entrance, a motor on the again—in order a secondary characteristic you get the redundancy. But it surely wasn’t finished with the first intent of getting redundancy.
How does Joby’s eVTOL manufacturing evaluate to EV manufacturing?
Wagner: Essentially the most environment friendly solution to run a large-scale engineering effort in a mature trade, comparable to automotive, is to interrupt your system up into items that may be outsourced to suppliers who’re going to do a extremely good job on every bit. The draw back is that once you break an issue up into three items, you now have interface boundaries between every of those items, and people at all times create inefficiencies. We have been capable of design extremely built-in options with out taking that manufacturing penalty.
Are there any supplies you’re actually enthusiastic about?
Wagner: Permendur [a cobalt-iron alloy] sometimes prices within the neighborhood of 10 instances as a lot as conventional motor metal. That’s vital, and it’s typically not utilized in floor transportation due to that value. It comes with small enhancements in efficiency, however sufficient that for aviation it’s fairly fascinating.
Will electric aircraft catch on like floor EVs?
Wagner: I’ve at all times needed to be a really ahead thinker with respect to power-train. Nevertheless, one of many issues I’ve discovered over time is that power-train improvement has to come back with a really wholesome dose of endurance. Creating an entire new kind of power-train is an enormous endeavor, nevertheless it’s one which I’m very assured the aviation trade will undertake. We’re actually enterprise it right here at Joby, and we’ll see that broaden, I’m certain, with time.
This text seems within the Could 2026 print situation as “Jon Wagner.”
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