The Real Reason Tesla Developed The Plaid Motor! 

When turning, the inner wheel needs to spin slower not faster. An easy slip.

Electric motor designer here. Great video. Even though simplified a lot at some points, I think you got your points across well. However you got some things wrong about the carbon fiber sleeve. Carbon fiber is terrible at conducting magnetic fields. Therefore, if you have a 3mm thick sleeve, from a magnetic point of view, its like the airgap is increased by 3mm. So the effective airgap is actually much higher with a carbon fiber sleeve. What carbon fiber is good at is preventing the rotor from destroying itself due to centripetal forces, allowing higher rpm. With higher rpm a very low aigap is actually not desirable due to increased rotor losses, but this is a complex issue. I'd love to chat about this with you, if you are interested let me know.

To turn or go around a circle, the OUTER wheels have to spin faster not the inner, as stated here!

15:11 It's comforting to see that the stator windings are held together with good old string

Fiber-wrapped rotors were researched extensively during the 1960s & 70s, where rotary-energy-storage was being developed. Such rotors were used in urban buses & vehicles, as inertial storage. Physical design actually shows that a rectangular-shaped rotor dies not have an ideal amount of energy storage. High-energy rotors use a "semi-cycloidal" shaping, as dependent on the strength of the fibrous windings. We looked at some of this while we were developing the Lunar-Rover motors. Fiberglass & Kevlar & Aramid fibers were used before carbon-fiber was available. The fibers actually do reduce the efficiency of the motor, since it is an airgap. However when the rotor expands, due to heating, the carbon can be shredded-off, and actualy "scrubs-to-fit" the stator. As such the motor can be self-adjusting to its specific thermal regimen. This technique is now used in aircraft turbines, as in C17, where the fan actually is made to grind-to-fit the containment stator. However, if the Tesla motor "overheats" beyond its design range, and if the carbon is shredded, and IF oxygen is available, that motor will actually combust and burn internally. Some other vendors actually suck-out the air inside the motor, to a semi-vacuum level. This improves the aerodynamic efficiency of the rotor. If rotor goes near-sonic velocity, in the gap, this creates major aerodynamic losses (shock waves), which will either heat the motor, or cause high-energy vibrations, which can also destroy the bearings. We ran into this in uranium-seperation equipment, at 60-to-90-thousand rpm. None of this technology is new.

Induction motors don't have permanent magnets in their rotors. A magnetic field happens in the rotor due to induced (hence "induction") currents in conductors in the rotor. Tesla uses brushless DC motors which have permanent magnets in the rotor and use electronic switching to control the polarity/strength of the fields in the wound stator. The commutator shown at 6:13 is a mechanical switch used to alter the field direction in a wound rotor. this would typically be used in smaller motors which have a pair of permanent magnets as a stator and are often seen in toys, also car starter motors. The commutated rotor can also be used with a wound stator, in the case of the universal motor, used in AC powered tools, like drills and skill saws. Induction motors tend to be large and heavy (there are low powered exceptions, like fans and old record players), but very quiet and very long lasting. Universal motors produce a lot of power and are comparatively small, but make a lot of noise and require maintenance when the brushes wear out.

Railway engineer here... What I've learned is that other than some minor design tweaks in the rotor which are specific to their design philosophy, that the power control and design of any Tesla or any other EV powertrain is basically the same as we have been using on AC traction on the railway since the early to mid 90s.

The outboard wheel always turns faster, it is traveling a longer distance in the same amount of time than the inner tire.

The star shaped design where the inner part of the rotor comes up to the surface in addition to the poles is so that it can partially act as a reluctance motor, this is presumably what that boost in power they mention is. Also, although the carbon does stop the rotor expanding, it is a bit more than that since it's literally the only thing holding the the rotor together, adhesives would not be strong enough and metals would introduce serious losses. I think they had a previous iteration where the pole laminations were actually part of the core laminations and that just could not have been nearly as good as this, although it did reduce the gap in the magnetic paths so it might have had higher torque.

For anyone fascinated by this as much as me, I want to recommend the Lesics video on the Model 3 motor. It goes into incredible detail on how brilliantly Tesla arranged their magnets to maximize efficiency.

I worked 38 years as a construction electrician, I worked 3 years as an Electric Motor winder, (I rebuilt electric motors) but there are still a lot of things I don't know of understand about Electric motors. I believe EVs are our future, I can say this even though I think we are not ready to shut down gas engines. The electric car has a lot going for it, if we get the batteries/charging worked out. Great video.

from someone who works in electrical trade sales: your history/physics lesson was fantastic, you gave an Intro to electric motors class in 5:30.

best explanation of how an electric motor works that I've seen, thank you!

Mechanical engineer here. The main reason for the carbon sleeve under tension on the rotor so that it prevents any further elasticity of expansion due to centrifugal force and thermal expansion which can cause the outer diameter of the rotor to rub against the stator. Very sophisticated thinking by Tesla's engineers. This must be done using FEA analysis.

Wow....GREAT VIDEO! I never thought I'd understand this but the way you put it in all your simplicity, I'm a friggin' genius now. Haha! Thank you for explaining this the way you did. This video was very well put together.

Thank you, this was so well explained, with just enough detail and language so that anybody can understand in a nice bite-sized portion. Love what Tesla is doing to evolve the electric vehicle and transportation as a whole.

At timecard 14:18 should be "the outer wheel has to turn faster."

Your way of explaining the subject is so clear and easy to understand. If only my professor can explain the content like you do. Definitely subscribed.

Fabuleous job! Love the simplicity in communication, particularly coming from such a heavy engineering subject.

Well done on the simplified break down. I have a preexisting knowledge on the subject and I felt like I gained a better understanding by watching your video. I’m in the process of creating learning materials for the company I work for and I wish I had your ability to make a subject comprehensible as demonstrated by this video.

Excellent presentation, my neurons kept up with you most of the time. Don’t ever remember a better motor presentation in all my 79 1/2 yrs ! God Bless &. Keep up the good work, I will definitely watch this again ! 👍👍👍👍👍 🇺🇸🦅

Fascinating! Thanks for talking this complicated subject.

When going around a corner, the OUTSIDE wheel goes faster... 14:18 It must travel further distance and keep up thus inside wheel is slower than the outside wheel.

As an simple electrrician, I found this video very pleasant and well explained, cudo's to you ! If the schools would have such good explanation to physichs and other technical programs, the pupils would learn better and perhaps World could be a better place !

Thank you for going above and beyond on this one. Value added, indeed.

Ya you guy's are doing a great job, keep up the good work. I am learning more and more every time I get a chance to watch. Thank you.

Thank you. Very important topic. Not covered enough even by the best tesla channels. Listening now

Plaid is a big win in power density mainly due to the higher RPMs it allows. This has 3 advantages in applications like the CyberTruck and Semi (both of which I'm expecting will use Plaid motors): 1. Lower weight -- the motor weight is reduced in inverse proportion to the increase in power density 2. Economy of materials -- the needed copper, aluminum, rare earths, etc scales in the same way 3. Reduced motor count -- CT and Semi will debut with 2 and 3 motors, not 4 and 4

Great video! I really enjoyed it, i was actually curious about the engine. Great job 👏🏻, please do more about the engine

The comments by the engineers are interesting and very detail. Keep it up guys. Thanks!!

Steamship / Hydroelectric Powerplant USCG Engineer here. If you think blackouts and brownouts are a big problem now, just wait ten years when millions of electric cars plug into The Grid at night to recharge. Better start fixing The Grid soon.

Great movie guys, you guys did a lot of work and it came out great. (Below are [3] small corrections I saw) *earths North Pole is magnetic south which is why the norther portion of a magnet points north (magnetic south *Centripetal acceleration (force) *outer wheel spins faster in a corner

Loved this episode too. Congrats 👏!

EXCELENT excellent demonstration, explanation & animation!!! I already know how this works pretty much. I wanted to do a vid just like this. Time not on my side. You did an amazing job!

Great job of pulling so many resources together to make a solid video!

This is the Tesla version of everyday astronaut

If the inverter goes dead for some reason, the (very strong) motor could slow down the wheel as if you had suddenly stomped on the brake (but only for that wheel!). The explosive fuse could disconnect the motor in such a case, letting the wheel turn freely.

Thud video was so well made and edited. I was fascinated through the whole video. Even though I know a lot about this topic I still feel I learned a lot from this video.

So many Tesla channels nowadays but you guys are clear and to the point without being pretentious. Compliments from The Netherlands.

Another fun fact, RC brushless motors have used wrapped rotors for many years. Not sure who holds the patent or came up with the idea. Pretty sure it wasn’t Tesla though…

Great video. I enjoyed learning a lot from this. There were a couple points I think were perhaps a bit confused. The first one was, copper isn't what becomes magnetic in an electromagnet, it's the ferrous component (the nail in the image used) that has magnetism induced by the current flowing through the copper wires wrapped around it. The other being the outer wheel has to travel faster, not the inner wheel, but that appears to have been pointed out. I'm not an expert on magnetism, though, so if my point is in error, someone with more expertise, please correct my mistake.

That was great and am happy about how the community helps each other understand the truly awsome tec unfolding thanks

@14:19 Slower not faster, the inner wheel must turn slower and the wheel on the outside must turn faster, because it has to travel a longer distance. Nice video! Thanks for share your knoledge.

14:17 The OUTER wheel spins faster, not the inner. I'm surprised this error wasn't spotted during even preproduction.

Wow, You killed this comprehensive cliff-note lesson on Electromagnetic induction motors. Outstanding !

Good, simplified explanation; nice visuals.

Time traveling engineer here. You forgot to talk about the Flux capacitor. Great vid.

With stronger magnets, you need less current on the stator to create a field for the rotor to follow, would be my guess.

Excellent video. I have owned 8 Tesla's over the last 11 years but have never heard such a clear description of how the amazing motor works. One minor point, when you describe the reason for a differential, wouldn't it be the outside wheel that has to turn faster than the inside wheel, rather than the other way around?

I remember when I was a little kid. We had these itty-bitty Hotwheels called "Sizzlers." I think the stators were permanent magnets and the rotors were copper-wound electro-magnets.

Nice coverage. Thanks!

14:19 No I believe it's the outer wheel that has to turn faster, as it has a greater distance to travel. Great video though. Very enjoyable watching this.

This episode is pretty amazing, seriously more tesla knowledge please 😅😇

yes ! a very nice video presentation at a pace i could learn. love the content so much

YERY interesting and well presented. Nice job and thank you.

What if I told you a brushless induction motor doesn't need permanent magnets? Anyway, the motor design is innovative but not surprising, imagine the magnetic field lines created by the field windings and it makes more sense.

At 6:13, the animation is a Direct Current Motor using brushes. You also kept switching between single phase induction motors (four poles) and a three phase diagram (six stator magnet working off 3, 120 degree separation phases for 3*120=360 degrees. Which you show only occasionally. All of this confusion comes before the explanation of the T in Tesla Symbol.

Good job and good use of existing content on RU-vid.

This is an excellent video - thank you for the layman explanation on how the induction motor works and then going into the specifics of the Plaid motor differences, as all the points come across really well. I walked away with a much better understanding of the motor basics and it helped to understand some of the details in Sandy Monroe's video that either weren't explained or were glossed over a bit due to assuming the viewer had a level of understanding that might not have been there.

Thanks for making this video, I think everyone needs to know the basics behind why electric cars are so good and why teslas are brilliant! IPM synRM plus the iron core rotator magnetic gap and the carbon fiber wrap (which doesn’t interfere with the magnetic field) is just plain brilliant!

I am an “ok” engineer with a regular job in a software company but learned a lot from this video. Wondering, if the real mechanical/electrical engineers working at Rivian/Ford would learn a hell lot more from this, and can dramatically increase the performance of their Cars, beating Tesla! Is that possible?

Thank you for explaining this so thoroughly. My one nitpick is that in this context non-integers should be rounded rather than truncated, so the Plaid required 152 N, the Model Y required 112 N, I3 was 94 N, and Mach E 82 N.

Nice. First time I have heard an explanation of the Tesla logo. Thank you!

Wouldn't the outer wheel spin faster going around a turn? at 18min That is a stargate motor if I've ever seen one. Rather than stacking the magnets on the outside though they used the stargate configuration on the inside most like adding more magnetic flux to an already powerful magnetic.

The Plaid was what I expected Tesla’s response to the Porsche Taycan to be. Porsche multiplied torque and increase top speed with a 2-speed transmission. Tesla did the same by doubling rear motors, increasing redline, and lowering gearing.

Well done. Another thing Sandy Munro mentioned as being different was the magnetism pattern surrounding the rotor wasn't staggered as would usually found in a typical electric motor...supposed to ensure smooth operation, though Sandy said he detected no jerky feeling while driving the plaid. Thanks.

…It was Tesla’s 166th birthday yesterday. _good timing_

three phase induction motor is very different from permanent magnet motor

the inner wheel will turn slower!!!

When you were talking about, brushless motors you actually had a video of a brushed DC motor in there. Haha I was like why is he showing that, he's going to confuse people. But overall really good video 6:18btw

Thank you so much for this video I've always wanted to watch 🙏

No, the OUTER wheel has to turn faster when rounding a corner.

I believe the 'explosive fuse' is detonated when there's a airbag deployment... therefore, immediately disconnecting power to the motors.

Fascinating and helpful. Thank you! ! !

Very insightful video! Well done guys!

In general, larger motors are more efficient, the inverse for transistor switching where smaller is better. The new frontier is driven by smart high-speed semiconductors that end up to very high wattage semi-conductors with very specific chemistry & reaction characteristics. Add to that the new permanent magnet alloys with higher curie points & add in new induction motor designs made possible by computers as high speed intelligent relays, & it’s hard to keep up with you don’t have a magnetic personality or are not in the field.

Not sure about the "floating caps" but as with transformers the reason the core is laminated is likely to better carry magnetic flux from the primary to the secondary windings and to reduce energy robbing "eddy" currents circulating within the iron core itself. These currents cause heating and energy losses within the core. Those floating caps are VERY interesting though.....hmm

That's actually amazing about the stronger magnets...not being held by anything!

Very informative I enjoyed watching your video always wondered how it worked.

When you hear idiots like Gordon Johnson who loves to state that Tesla has no competitive advantage Technologically or Materially it just puts things into context. Only 3-4 years ago Tesla was at 100k units a year and ramping up the the Model 3. Now we're at 1.5 million and the Model 3 and Y are two of the most popular Cars in the world. And that's not just for EV's that includes ICE with a clear lead in the US and Europe. I don't know whether Tesla can get to 20 million units by 2030 but even if they only got to 10, 12 or 15 million is anyone going to really be calling it a failure? Afterall even at 10million units per year which is where Toyota and VW were before COVID neither company came close to Tesla's gross margin! So 10 million units at an average of 30% plus gross margin would mean a gross profit of 180 billion? Not bad considering the experts have been writing off Tesla since it was founded.

Great content, Money is worthless until you put it to work.... I made my 1st million investing in Crypto. Making money is the plan and with investing in crypto your plans can be fulfilled

WOW man, you hit a Super Grand Slam in this video!!!!!! Sup;er Clear and easy explanation covering all the details of why the Plaid is the strongest and most advanced electric motor!! You were even more clear than Munro's video, and that was a super video too!!!!! Keep on your good track and work!!!!!!!

Fantastic! So informative. Thanks

Excellent content, thanks for the work explaining this. Superb!

Nice work, content, and information.

WOW! This is a wealth of information. Thank you for sharing.

Thinking outside the box is a critical gift of genius at work.

Impressive detail AND explanations! 👍🏻

Very cool stuff, great info, really interesting. thanks for the breakdown. Good video!

Thank u for explaining this to me :)

I LOVE it. At 3:40 the illustration of a wound coil image left is an impossibility. Oh yes, I know you could construct a prop with the wires on the back side chopped or rerouted. But having both windings appearing from the same side? Nope !

I love how when talking about the Plaid motors in the intro you show a closeup of a Model 3/Y subframe. Lol like it has nothing to do with what you’re talking about solid editing

You did it very well. And it was very interesting. Thanks.

That was very satisfying for a techie like me. Thanks.

The info is very good ans only manor thing in the description of a turn is that the inside wheel would turn slower and the outside wheel would turn faster. Other than that I like the video very much! Keep up the research and production of more video’s!

Great info. Thanks!

Beautiful! ❤ I’m pretty sure that fuse is if that epoxy breaks and prevents a rotor blowout accident.

Fascinating. Thank you.

Excellent presentation, thank you !

Great job simplifying it