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Tesla Motor Mouths

Two teardown experts have a spirited discussion on electric vehicle drives.

Sandy Munro tears apart cars and other machines for a living, deducing how they’re engineered and built, then sells extensive reports on the teardowns to suppliers, competitors and hopefuls. (The Tesla Model 3 Benchmark Report, for instance, runs more than 2,000 pages and costs $87,000.) He and his band of engineers, lean experts, cost analysts, statisticians and more have analyzed hundreds of electric vehicles since the late 1980s.

“We’ve got a fairly broad background here on what an electric car should look like, and what an ordinary vehicle should look like, too,” the former toolmaker (and ex-Ford executive) explains. He received considerable press recently for a teardown of an early Tesla Model 3—as well as advice to tone down his colorful mechanic-speak. Telling the world that he could see the gaps in the Tesla body “from the moon” apparently put his attorneys on edge.

Unasked, Munro also sent Elon Musk 230 ideas on how he could improve the build of the Model 3 and make it more realistic to manufacture. “I have no clue if he implemented any of it.” His motive was avuncular, he says—he wants Tesla to succeed because it’s the only automaker doing anything innovative.

“But I’m not interested in buying one of [Musk’s] cars—not yet,” Munro says. “I am, however, very interested in seeing what he is going to do next.”

Munro and his battery expert, Mark Ellis, shared some insights on the Model 3 and three competitors—the Chevy Bolt (200 hp), the BMW i3 and the Jaguar I-Pace—in advance of a study on the vehicles’ electric motors that they’ll release in a couple of weeks.

“It’s quite interesting to people who are trying to figure out how to figure out to build an electric vehicle,” Munro says. “Because quite frankly, they’re not that easy to build and there’s a vast amount of difference between a Tesla motor—their PM [Permanent Magnet] motor is the most advanced motor we’ve seen, period--all the way to a lot of old-fashioned technology that really doesn’t do much for the driver as far as excitement is concerned.”

Here are some takeaways from their interview:

If Munro had to pick only one thing that distinguishes the Model 3 motor, which is the lightest of the four and has the most output, it would be the casing.

It’s made with a special material (iridium) that gives it a little bit more refracted power,” he says. “So there’s a very, very small amount of a material that we discovered kind of by accident that helps it out.”

The magnets in the Tesla motor are “vastly different” than the other contenders.

“Instead of having one solid magnet, this magnet’s been glued together,” says Munro. “It’s four magnets that have a magnetic charge that is counter to what you’d normally see. So they’re glued together, and that gives you a much more dense flux, which is what makes the motor really work. And that much denser flux is what one of the key factors that is making it a very, very fast and powerful and little electric motor.”

The Tesla motor is also the cheapest … they think.

“We found out lots of stuff in this detailed report we’re writing and we may have to revise the price,” says Munro. “The Tesla has a lot of stuff hidden. The Tesla is a big mystery. It’s not obvious sometimes what clever things they’ve done. That’s what makes it more fun, I guess.”

For car detectives, the Model 3 is the gift that keeps on giving.

“There’s mysteries every day,” says Munro “We thought we were clever, but we’re not that clever. I mean, there’s no fuse box in the Tesla. None. That was a big surprise. The high voltage has a disconnect. It’s not really a fuse. It’s more of a squib. It’s like a little explosion. If the car rolls over, they have a little disconnect that blows up. So when it blows up, it cuts all the power to everything and that way you don’t have an electric nightmare.”

When his colleague Al discovered the magnet configuration in the motor, Munro got curious, took it over to a vice and gave it a tap with a hammer to see if he could break a magnet free. The whole thing exploded.

“That magnet was under lots of stress,” he said. “Those magnets were trying to push each other away, but the glue was holding them together. We’ve never seen anything like that, ever. We started digging into it and we found that the idea behind that has been around for a long time, but no one’s ever figured out how to do it in high-volume.

“We’re in the process of investigating that now. We’ve talked to lots of magnet manufacturers, but this might be another one of these made-in-Tesla kind of deals. They make a lot of stuff in-house. They’re not like a conventional automotive company where they’ll use a lot of different suppliers.

The BMW motor is the heaviest and most expensive, and it has the least amount of power.

“So, go figure,” says Munro. “It’s a very inefficient motor. It’s not designed for … I don’t know what it’s designed for, really.”

Telsa’s invertor/convertor—the device that takes the battery power, and supplies that power to the electric motor—is very advanced.

“It’s also inexpensive and it’s a very efficient design with the best circuitboard system I think I’ve ever seen with anybody, including other industries,” says Munro. “It comes in at about $800, whereas the BMW was $1,100 and the Chevy Bolt was about $753.”

Telsa’s the only automaker that uses silicon carbide on the integrated circuit (power supply) invertors.

“It creates a lot less heat and is a lot faster than the Chevy and BMW,” says Ellis. “Silicon carbide is the latest and greatest and Tesla so far is the only vehicle out there with it.”

Overall, Tesla’s motor is considerably smaller and more high-tech than the others.

“It looks like the other guys just went around and glued together whatever they could find off the shelf,” says Munro. “While everything on Tesla is ‘Where’d that come from? It’s very, very efficient engineering. Everywhere except for the body, which is not so good.’”

The Tesla body, “looks like a kids’ high school project,” says Munro.

“I don’t think anybody could manufacture that body at any kind of production rate and have a high quality. It’s got too many parts, too many materials, too many fastenings. It’s like [Musk] wanted to try out every technology he could, ‘Hey let’s use laser welding and let’s use straight welding and let’s try arc welding over here and this kind of spot welding, concentric circles spot welding, or ordinary spot welding, and oh yeah, then rivets, my all-time favorite.’ There’s a lot of self-piercing rivets in the car. And a lot of adhesives after that.

“The body is really near impossible to put together. I ran plants at one time, body and white departments, and if some engineer had given me that design, I would have personally tattooed my initials on his forehead with my best right hand. That’s the kind of stuff that drives people in the plant absolutely nuts. For instance, there’s 13 parts to make a wheel inner closeout—that’s one part in a normal car. Who in the world would do that? And by the way, it’s made out of two different kinds of material. It’s made out of steel and aluminum. That’s just plain old goofy stupid. And then it’s got a whole bunch of caulking that goes around it and it’s just all over the place. It’s a nightmare. You can’t win when you’ve got a whole bunch of dinky parts that you’ve just got to weld and use rivets. It’s ridiculous.”

The Model 3 battery design is “brilliant” in its circuitry design and how simple and lightweight it is compared to competitors, but there are issues with its manufacturing.

“The assembly to put the battery back together is a virtual nightmare,” says Ellis. “It’s very time-consuming, it’s very labor-intensive. Like I said, the overall philosophy is great, the actual doing of building the battery pack, they’ve had to buy specialized machines to try and help with the assembly efforts.”

Overall, Tesla’s electronics team is “like a whole bunch of Sheldon Coopers that actually get along with people and don’t insult each other.”

“The Greek guy they hired [Chief Motor Designer Konstantinos Laskaris], this guy is absolutely stunning,” says Munro.” All he thinks about are electronic motors.”

The other automakers had “a couple of cool ideas” from a manufacturing standpoint.

“But it wasn’t like, ‘Oh wow, we’ll never see anything like that again,’” says Munro. “Whereas the Tesla is loaded with technology. The body on the BMW was phenomenal, one big giant lump of carbon fiber and the aluminum welding technology—on the other end is Tesla’s nasty body and horrible design, but everything else on the Tesla was brilliant".

The Bolt “is a farce.”

“It’s just a cheap little car with a battery and an electric motor,” says Munro.  “One thing you can count on, GM will be able to make a cheap car. GM has always done the same stuff. Their [engineering department will] design some kind of a vehicle, and then somebody in accounting will say, ‘you’ve got to make it cheap.’ But it won’t fast and it won’t go far.”

 

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