20:57 "That's not really a guess, that's just an engineering assumption." 😂

It's good to hear Ben's voice in your video. I thought he was a good presenter and a real value to Munro Live.

On the monoblock vs segmented magnets, I would recommend using magnaview film to see if the magnet is segmented inside of the external plating. The other thing to check is the electrical conductivity of the magnet to see if they added anything to the magnet that would reduce the electrical conductivity before sintering it. Both methods could be used to reduce eddy currents.

I just love these Monro cybertruck reveal videos. I'm embarrassed to say they remind me of an old time burlesque show. Where each week the Cybertruck takes off a little bit more. Thank you for not playing bump and grind music.

Appreciate you included more of the teardown

Dear Mr. Munro and Team, I wanted to extend my heartfelt appreciation for the incredible work you all have done in meticulously disassembling and analyzing the state-of-the-art machines. Tesla’s attention to details and dedication to refining their design and technology are truly remarkable. I was particularly fascinated by the hair-pin windings which I saw in some recent cars alternators. To me, they are a piece of art. No wonder why tesla is the ev-leaders, the mindfulness and understanding displayed by Tesla engineers in perfecting even the smallest details is truly commendable. Thanks

That bearing rotation constraint is most excellent !!

Great video, thank you so much for putting this for free! Some thoughts on the non segmented magnets: First of all, yes there are eddy current losses in the magnets but they are quite small compared to iron and copper losses. Still they can be problematic since they are the heat source in a temperature sensitive part. One problem with the segmentation is that you will lose some torque because of having less magnet material in the rotor. This will make the motor a bit less efficient. I think that this loss of efficiency could be more than the additional eddy current losses. However, these eddy current losses are mainly due to the current harmonics caused by the PWM. This means that you can drastically influence the magnet losses by the PWM. Maybe Tesla optimized their PWM in order to reduce the magnet losses for not having to segment the magnets.

that spring loaded pin to catch and stop outer race from spinning is so smart of an idea.. and Sandy's response "so anyways..." lol

The disassembly intro adds context and perspective. If you were to add them to most of your videos we all would get a lot more out of them... THANKS!!!

"It's not a guess. It's an engineering assumption." Best Sandy quote ever!

This kind of videos really benefits from Sandy outlining the wider meaning and historic place of all the technical details. As a software engineer I otherwise wouldn’t quite catch the showcased engineering genius 🙏🏻

Would love to see more of those big honking gears, that's some pretty wicked stuff. Machined, smooth, shiny metal - practical and beautiful all at once.

I am no electrical engineer but Tesla uses segmented magnets in their other motors. There must be a valid reason why they changed. I remember a few years ago Sandy was surprised at segmented magnets used in the model 3 motor

Cooling the magnets makes sense, because overheating a magnet can reduce it's strength permanently.

"You'll never get that (half a million miles) engine life from an ice car." I'm real damn sure a couple of ICE cars have passed a million miles, not just half a million.

All motors can be "turned off" in motion; the difference between induction and PM is the magnetic drag while unpowered, as more clearly explained in another Munro video by Paul.

Kudos to Munro and associates - all your presenters are very experienced and do outstanding presentations. Excellent information and excellent naught.

The rambling about induction rotor construction starting around 19:07 is almost entirely incoherent. I think Sandy wanted to talk about skew, and stumbled into rotor construction as a result. In the end, the construction of the induction rotor for the Cybertruck motor is not described, and how longitudinal grooves might help motor operation is not explained. An induction motor's rotor uses electrical conductor windings which are shorted, so changing magnetic field from the stator induces a current in them, which produces the rotor's magnetic field. The windings can be constructed of wire, but that isn't done in EVs; instead, EVs use "squirrel cage" rotors, with a cage of lengthwise conductors which are shorted to each other at the ends. Regardless of how the conductors are made, the rest of the space is filled with a stack of iron laminations, just like a permanent magnet rotor for a synchronous motor. The old copper design has the conductor bars and one end plate expensively machined from a solid block of copper. The laminations are then stacked into it and the shaft, then the other end plate is attached to finish the rotor. The aluminum conductors of the newer design of rotor are cast into the spaces left for them in the stack of laminations. That means less waste material than machining from a block, and a less expensive manufacturing process; it also uses cheaper material (aluminum instead of copper).

I love this truck even MORE now that I see the innards

thank you for having sandy and other presenters in this one. sandy makes the material watchable.

I love induction motors! Such a indestructible design, soo easy to drive without all the position-sensing hall sensor junk. Makes me happy that they still use them even in modern electric cars

More than just the non-segmented magnets, having that rotor end plate run to the rotor OD would generate unnecessary eddy current losses since they would be exposed to some of the magnetic flux from the stator field. In terms of the magnets, I'd be surprised if Tesla weren't on top of the gains segmented magnets can offer and I'd suspect they were not that significant, especially since the magnetic flux at part load operation is pretty modest compared with full torque so the losses would be not huge for most of the time.

My Honda Civic at 460,000 miles says otherwise. I got that out of a piston car. It's more than doable if you regularly maintain.

Paul was really a great communicator in this video.

_Extraordinary Engineering_ That was an engaging teardown boys! Can't wait for the next one....

I really love this type of video. Thank you for sharing; it's very informative.

The rotor end plates are called DE and ODE balance rings. DE is "Drive End" and ODE is "Opposite Drive End". You could get through rotor cooling to the magnets if you just perforated the balance rings. That's probably not the reason they aren't the same diameter as the lamination stack. Near net shape shafts were used in the GMT900 program as far back as 2008. We had a rotary hammer forge that fed our machining process.

Love the bearing retention detail! Huge improvement for reliability/life cost. Some bearings have had pins/nubs on the outer race to prevent spinning and I've never understood why more of them don't.

The supplier videos are excellent, the 3 D Services Group look to be extremely impressive.

I think the magnets issue is so that tesla intentionally makes the motor hotter so that it can use that heat to keep the battery warm in colder weather. It is really the only motor that is running most of the time and especially on the highway. So, there is a lot of heat loss in colder climates. Basically, they don't have to add a heater, but then they can modulate the cooling for hotter climates, or even shift the work to the induction motors. I am just guessing, but I'm usually right.

Could it be that the magnet is segmented internally, inside the outer plating, or made of a less electrically conductive material to reduce eddy curent losses?

I'm glad we have you two as Americans. I hope you have contacts at the DOD -- they need some more folks like yall in their rolodex.

Induction and PM synchronous motors sharing stator design is good, but not new - Tesla has done that since their first PM motor, in the Model 3. Like the Model 3, the axial lengths are different, to suit different flux density and power requirements. Long before Tesla, Remy (now BorgWarner) offered their HVH series (which is also bar-wound with hairpins) with a choice of induction or PM rotors using exactly the same stator. It's good to see Tesla continuing this practice, and finally catching up to use bar winding.

When engineers sound like a kid in a candy shop. Buy it.

The thick aluminum end plates on the PM rotor, if it is closer to the stator will have higher eddy currents that is not good for efficiency. If cooling is the reason why not have some holes on those end plates.?

Great info. Thank you to the whole team.

Be interesting putting two of these motors in one vehicle 😀

i assume at this point in the tesla story...if there's a design change or something that is "inexplicable" then it is for a damn good reason.

At Investor Day in March 2023, Tesla announced that it planned to move away from rare earth metals in future motor designs. It would be interesting to hear if Tesla has managed to do this in the Cybertruck's motors.

thanks Munro team!

Thank you for educating us, great content!

this is just an amazing 20 minutes piece of knowledge. THANKS

I learn a lot from Munro, Tesla and others; Thanks! - With the Cybertruck I see a certain amount of over-engineering and a vehicle that no longer helps many people in their daily lives, and there is no blessing from Above. - On the other hand, useful vehicles for many people, in many regions and many terrains in the world, small and affordable, robust and simple, economical "Model 2" are needed! Small cars for 3, 4 or 5 people, with a length of 2.8m to 3.5m (!), that is my area of work and is on the rise. Because there are already enough big, expensive “dinosaur cars” that will die out, but the little clever things give the world hope.

Heat can reduce or destroy magnetism. So cooling them may also increase magnet life/power.

I smacked the "Like" button !

12:00 The first time I saw Sandy was before the Pandemic, on Autoline After Hours. . . Showing John McElroy Tesla’s “Secret Sauce”, pulling a segmented magnet out of his tweed jacket.

The segmented magnets make great sense if the truck is only operating in hot climates. But Tesla uses motor inefficiencies to generate heat to put into the heat pump that keeps the battery and cab warm. It may well be that when they run the calculations, the extra heat is required more often and the solid batteries allow this to be generated faster and at less electrical cost. Rapid warm up and keeping the battery warm is very important. Not to mention creature comfort.

“Piston car can’t go 3/4 million miles,,,,,” 30 years ago Lexus causally makes the LS400 which can go over million miles 🤯

Amazing the amount of power those little components on the inverter board’s control. The whole truck is awesome.

little drill marks on the induction motor casting to maybe balance it like balancing a tire?

This *has* to be watched at 1.5 playback speed. The anticipation was killing me.

So to be clear on the front differential- it's not limited slip, it's an electronic locker- giving a true Detroit locker type of performance?

Power is in Watt, why still use these archaic HP ? And which one ? The one = 746W ? Same for torque, Nm etc...

The motor is a work of art

14:50 Munro, are we sure there are significant eddy currents in a Permanent Magnet Synchronous Motor? The whole point of the word Synchronous is that the magnetic pole from the stator is rotating in phase with the rotor’s permanent magnetic field poles. If there is significant pole slipping (relative movement between stator and rotor) then I think there is a problem in design or control systems. Relative movement between the field and conductor is required for an eddy current.

Sandy and Co. = National Treasure. No I am wrong= International Treasure. (Though I can tell you as a multi plane owner in times past, Sandy, that aviation venture was doomed from the start. Nothing is tougher. You have balls to even have tried it.

Amazing what EV’s have done with just first generations. Just think a few more generations. Battery tech is also rapidly changing

15:00 Land Cruiser 70 series : "Hold my beer Sandy" 😂😂😂 (just one example that they can)

Awesome wideo! Thanks for sharing knowledge! Greetings from Poland!

AMAZING! THANKS FOR VIDEO!

Wow, the fact that they have to explain about how they are not going to get shocked. I didnt think that many people dont know about batteries and d/c power. Yes it can shock you but, its not like a/c in how easy you can get shocked.

Interesting that Tesla cheaped out on the motor magnets while also giving Cybertruck a smaller battery than other e-trucks. I think they're sandbagging on early Cybertrucks, not thinking Chevy would beat them on range by loading up a bigger battery pack. Perhaps sometime in or after 2025, Cybertruck will get a "refresh" with a bigger, better battery pack, and a few other tweaks to get real-world range over 350 miles without an extra battery.

Ben's explanations have been awesome! Thanks to both! 👏👏😍😍

Thanks! Wondering if the dual motor will have a similar set-up only reversing the PM with the induction motor. Also wondering if having the induction motor up front turned off at highway speeds would help with noise vs having the PM running all the time.

thank you sandy n team

Excellent video.

Great craftsmanship.

Really thanks sir ,god bless you and your family

how does the grooves on the lamination of induction motor rotor cage eliminate torque ripple? and how is it better than skewed rotor?

Sandy is the man.

There is no need for segmented magnet in the rotor as there is no changing magnetic field. The rotor rotates and always aligned with the direction of the magnetic field.

cost cutting @11:00

Wonder if the front and rear inverter are all the same...I would imagine so...but surprised they didn't mention it.

Anyone else notice how good the electronics look? Cheap PCBs are not that color. I'd love to see the soldering points underneath and some better close ups

I bet Munro's about to sell a whole lot of Cybertruck teardown reports once this series is finished.

If the PerMag motor is driven by a true sine wave inverter, there should be no flux modulation on the permanent magnets. As long as the new rotor as paired with the new inverter, there should be no induced eddy current, so no need to segment the magnets. Another difference may be switching speed. the higher the frequency, the less coupling between the stator and rotor, further reducing induced current into the rotor. the magnets won't see the switching frequency. The same holds true for the induction motor. There shouldn't be any current induced into the conductor bars, that doesn't contribute to torque.

I'd really like to understand why they do not go for a two motor configuration on the front, similar to the rear but two permanent magnet motors. Seems like this would eliminate the need for the mechanical differential and the associated differential lock mechanism as well as allowing full variable torque control rather than just an on/off lock.

Great video and I hope your hands getting better love the work you’ve been doing in that area too

You may want to break open the nickel plating on those magnets in the cyber truck motor. Double check that they are rare earths because they may not be.

Thanks fellas :-)

750000m LOL. Thanks, haven't laughed that hard in quite a while

Damm, they are huge motors... it is funny how simple this is, the inverter is maybe the most complex part of the motor. A gas engine might be 1000x more parts, car manufactures love having tons of parts that can break

Great content, bring back the younger engineers please.

Love these videos. I agree with the excitement factor of seeing this beautiful cutting edge engineering of the future. It's truly inspirational.

gas engines can go awhile .. I got 1.3 million miles on a 87 suburban on the original engine ..700r4 sucked so 5 transmissions, and maybe a dozen water pumps and a timing chain set ..

There is no loss due to eddy currents on the rotor of a permanent magnet motor. The rotor in a permanent magnet motor always sees a constant magnetic field even while the motor is turning.

Only by Munro... thx folks for the teardown and comments, this info is priceless both for existing and future EV owners. Keep on building great name!

Glad to see President Snow back at it again.

yes! the motor break down.

At 13:30, why would anyone familiar with motor design think that an interior permanent magnet would be a Halbach array? Those are only useful in surface-mounted applications.

Wow Just incredible engineering, tesla sets the standard.

Regarding the mechanical rear diff locking, why would that be needed when you have two servo-controlled motors with positional feedback? Surely they can simply command that they follow the same motion profile to come close to emulating a locked diff? The induction motors might not be quite as smooth as PM at low speed but I wonder why that wasn't done as it's a far cheaper solution, even if shaft resolvers of a higher resolution were needed? The bearing outer-race locking feature addresses a problem when over-sized ball-bearings are specified to handle helical-gear thrust loading, including cases where a tapered-roller pair would normally be used. It avoids the finicky preload setup on assembly but introduces a new problem because the minimum radial loading required to avoid outer-race spin in a slip-fit assembly situation is not achieved. This is a clever solution from Tesla as the spring pin even avoids needing to index the bearing during assembly. Thanks for the video, Munro team, alway interesting!

Put my two cents in and say the benefit of segmenting magnets is a little overstated here

10:13 I hope the diff lockers can be engaged via an option and not automatically engaged when in off road mode.

Terrific overview.

I, to the segmented magnets!

Why aren’t the segmented magnets in a halbach array?

Awesome!!! Thank you so much!!

Wound motors have more surface area then hair pin motors, with that wound motors have better frequency response providing higher torque at high RPM, not necessary for a truck.