40 years engineering in big auto ICE, 20 years following EV development. Never thought Id see the day EVs would be allowed to reach their full potential let alone get a deep dive into the engineering. Thanks to Tesla for leading the vanguard and to Munro for letting us in on the detail. Done with skill full genuine enthusiasm transmitted on this brilliant channel, just the best 30 minutes.
15 years ago I had a RAV EV. Everything that was bad about EV's back then was solved by Tesla. Features and devices and specs. Tesla made it practical, eventually no doubt, will make it affordable.
Rotor is wrapped under high tension, you can't just slide a sleeve over after the fact. You also have no need for multiple directions because 99% of the load is hoop stress from centrifugal forces. Knitting it would actually just make it weaker because the threads would have sharp bends in them.
I think Elon Musk explained it some time ago how complicated it was for them to make those fibers wrapped and how their engineering team came up with a unique method to do it in house.
Exactly. Can't slide it over because it's under extremely high tension. The whole point is to keep the motor from tearing itself apart at very high RPMs.
The carbon fiber layer is wound extremely tightly to prevent expansion at 20,000rpm. Sandy's recommended method would not provide the pre-load compression that is needed to maintain tolerance.
Actually it is wound under high tension, Tesla developed machinery in-house only for this process. And yes, the unidirectional winding serves the purpose to counteract centrifuge forces the best.
True. Additionally, since the carbon windings are there to stop the rotor from expanding outwards, they don't need to provide any sideways strength. So any sideways weaving would only be dead weight. And any sideways weaving of the fibers equates to tiny bends, which would weaken the material.
I was quite frankly astounded that Sandy made a recommendation like this without researching the deep physics behind why the carbon fiber wrap. Quite an uncharacteristically flippant comment from him.
Rotor magnet skewing is nothing to do with physical torque pulsations that you can feel, because of the high effective rotor inertia and the high gear ratio between the rotor and the wheels, meaning the pulses, should they occur, happen far too rapidly to build into physical oscilationjs / vibrations. What the skewing actually does is make the backEMF of the machine more sinusoidal, meaning the 5th and 7th harmonic of the fundamental drive frequency is a lower magnitude. If you drive the machine with basic FOC, then the output votlage waveform is sinusiodal, but the backEMF is a modified sine (with the 5th & 7th harmonic components as mentioned) which causes a current ripple. That current ripple not only reduces motor and inverter efficiency, causes a high frequency EMC emissions, cause perturbations in the FOC current control, but also prevent one from running as close as possible to the average power switch current limit (because the peaks would cross the limit when they occur). This is especially an issue with very low inductance machines, ie high power / hgh speeds ones of course. What Tesla maybe doing is running with an active "feedforward" 5th and 7th harmonic cancelling voltage waveform, rather than relying on the axis current control to simply attempt to follow the backEMF. In effect, the inverter is actually now putting out a non-sinusoidal voltage waveform to match the non-sinusoidal waveform of machine! Do this, right, and you get higher efficiency, more power, and can run closer to the utlimate limits of the system, and you can run with a significantly stiffer current control loop too. The downside is your fundamental switching frequency needs to be high enough to be able to accurately synthesize this higher frequency voltage waveform, which requires faster and harder switching of your power elements, and a faster control loop to generate that waveform.
Another bonus of watching Munro vids. There are intelligent viewers watching and willing to shed additional light on things. Thank you. Honestly, I only understood the basic gist of your explanation, being a thumb smasher with only a bachelor's degree in "alternative" engineering.
You absolutely can feel cogging of electric motors in EVs that aren’t designed to avoid it. (At low speeds) the host of out of spec motoring points this out all the time. I’m not qualified to disagree with or confirm anything else you said though. Sounds legit.
On the carbon fiber winding, as close to radial as possible is the best. The filament winding industry calls this a “hoop” wind. With wet, or prepreg winding, the flow of the resin allows the individual fibers to nest into the previous layer’s surface. This makes the composite load up in unison as the rotor spins up. Using a woven “sock” will not match the efficiency of the hoop wound sleeve. As the woven fibers cross each other, the fiber is bent, or kinked, as it crosses every opposite angled fiber.
and a woven design might cut itself where the fibers cross. when pneumatic tires were invented they tried woven reinforcement. the tires kept blowing in 50 miles. they found the cords were cutting themselves where they cross. no tire has woven cords . each layer is parallel cords. granted in this rotor that may not happen but non 90 degree cords don't increase the strength and do prevent nesting.
I can’t wait to see the unconventional Cybertruck torn down to it’s bare exoskeleton. It will fascinating to learn about the design, manufacturing techniques and materials used in the construction. Bring on the Cybertruck!
@@Dive-Bar-Casanova You like the planned obsolescence & inability to get usable parts from a scrappers, because the mountings are different between model years?... Or the electrical plug shape & pinouts using the exact same wires?... 🤦🏻
Sandy, the tolerances are too tight to be able to slide over a carbon overwrap knitted. That's why it has to be applied directly to the spool under tension. Especially as the shaft expands and contracts under load and heat.
Correct. The fibers are wound under extreme tension. A cross-fiber knit would relax and not give the needed tension to keep the rotor from expanding at very high speeds.
@@bobsbeard3977 There's no copper in the rotor. Yes, Musk talked about copper in a video about the rotor wrap, but he often doesn't know what he's talking about.
I believe that explosive disconnect was a lot more impressive than you may have realized as it happened way too fast to appreciate fully. If you pause the video at 24:39 and then move though it frame by frame, then the explosion was bight and visible in exactly three frames. If you are working with a computer keyboard you can go forward or backward one frame at a time. After you pause a video, pressing the PERIOD key moves the video forward one frame at a time and the COMMA key moves it backward one frame at a time.
Sure slowmo of explosives is always interesting, but what about why?? Seems to be a way "someone" can take control and bring your car to a stop at command. Please take the remote off switch out.
I did the frame-by-frame view (Thanks for the instructions) and count it as two frames with the explosion in them. Also when I kept advancing to watch the debris flying I notice that the frames come in identical pairs. So in postprocessing editing, the software doubled the number of frames to get the frame rate desired for uploading to RUclips. This means the explosion was only a single frame in the original video.
@@ryuuguu01 Thank you. Good to get input from someone knowledgable in video processing. Based on your more critical look at these frames it seems like the event was only really captured on just one frame - so lucky it was caught at all. It seems like the event was even quicker than I was led to believe.
On my MacBook, the flash occurs at 24:33 (24:33.53, actually, at an apparent 30 fps). It was visible in one frame only. Then in the replay, at 24:40.33 for two frames, still at 30 fps.
I am an engineer ind the electronic industry (also worked in foundries, metal sheets etc.) for 20 years and a great fan of lean manufacturing - and I have to say that it is a great joy listen to you. Your are true experts with deep technical unterstanding. Bravo!
That inverter Phase bus bar pyro is VERY clever! It enables one to have a completely fail safe mode for a permanent magnet machine in the event of a loss of field control in the field weakening region (un-controlled regen ). It also cleverly uses HRC rated fuses to provide the final arc quenching, otherwise without those the severed section of bus bar would just arc across once opened by the pyro!
Yes I agree That's an excellent way of assuring safety with a permanent magnet motor capable of creating so much current... You can tell Tesla's big brother's SpaceX.
I was a bit surprised that they didn't secure the lugs as they would be in the assembly so that the pyro sees the stiffness it was designed to interact with.
@@w0ttheh3ll A large part of it goes through the thin part that gets sheared off with some going through the outer part that's left intact. That thin section is generating significantly more heat than the rest of the bus bar but it's solid copper directly attached to it so the heat is dissipated in the cooler parts of the rest of the bus bar. It's only necked down for a very short distance so the total resistance from the inverter to the windings is only negligibly more. The very clever part is how they shear it quickly enough to get it completely disconnected before the fuse for the outer part blows which is what actually disconnects power. High power fuses are a challenge to design and build because once there is an arc in air you only need a threshold amount of current to sustain the arc. DC applications are even more challenging because with AC you'll naturally pass through 0 amps 120 times a second for 60 Hz power which makes it much more likely to quench an arc. Inside the fuse you'll have stuff like the fuse wire being spiral wound to increase the length and it'll be filled with sand to help quench the arc and keep the energy released from just bursting the fuse apart like a tiny explosion. By having the split bus bar they can use a fuse that doesn't need to carry large amounts of current, just be able to quench a dead short from 800V to ground at high fault currents. That's a lot easier to do when you only need to carry 50A during normal operation and 10kA in a fault. So long as the pyro can sever the normal current path before the fuse blows then you're not dealing with trying to quench that high power arc in open air or with a very large expensive fuse.
@@AndrewMerts Thanks for the explanation. So they can get away with a much smaller fuse because in normal operation, most of the current bypasses this fuse anyway?
I was totally impressed the circuit board was made to fit the housing. You got to love vertical integration. Well thought out engineering very refreshing.
There was a lot of talking about quality issues in the past - mainly about aesthetic ones - but when you look at the quality of the components and manufacturing methods used Tesla tends much more to the higher end than other EV manufacturers. And of course the "symphony" of arranging the components is of the highest quality :-)
Yup, when people say Tesla has "poor build" it makes me angry. This is Ferrari was in its early days, cutting edge eng and motor design, but average 'body design'.
@@archigoel the difference being Tesla look and listen to issues, Ferrari didn’t, not even when Mr. Lamborghini had a simple solution for Ferrari’s poor clutch wear. Tesla definitely look to innovate on the basis of improvement rather than aesthetics. You know it’s a very good product when Sandy is so impressed he’s momentarily speechless 😂
At least visually, the build quality and engineering of Tesla’s running gear seems to be world class. Personally, I believe there is room for better quality of Tesla’s coachwork. If I had to pick one to have more refined engineering than the other, it would be the running gear, of course.
The carbon wrapped stator comes from rockets, let me explain. In rockets we use carbon over pressure vessels to make tanks, these are thin metal tank that are wrapped with thin strip of carbon fibre, these can take pressures of 5000 psi. With the magnets in the motors trying to push away from each other using carbon fibre wrap makes sense so you can hold in the magnets even tighter. If you use a woven cloth then the seem becomes a weak point of failure which would cause the motor to explode, wrapping is the olny way they could do it.
I might be mistaken, but I believe the woven tube Sandy was talking about would have no seam. But, in my opinion, Sandy is incorrect and as mentioned in another post, the winding will be stronger.
Came from rockets, that came from... old steam cars. I recall at least one had its boiler wrapped in piano wire to enable it to hold a higher pressure.
@@winksaville The carbon needs to be wrapped under tension. The carbon itself is laid out on the tank in a criss cross pattern so it is very much like a woven cloth. have a look for "Making COPV" on youtube and you will see how it's done.
I'm so glad that Sandy and co could hangout with Tesla and SpaceX! I think that helps show Sandy how serious Elon is.... no other CEO is in the ballpark....
@@BillboVonPonce Sandy said they should use a woven wrap. Carbon fibers are only strong in tension. Woven wrap means it would be thicker and use more material but would be strong in both directions. However, this would make no sense here because the stress is only in one direction; the motor rotation is basically stretching outward at high speed. So Tesla's approach of just wrapping the fibers in this direction is better.
@16:15 a woven fabric doesn't make sense; the uni directional fibers are keeping it from expanding radially. they only need tension around the circumference, there's no bending forces on the rotor, nor any axial loads.
Pyro fuse on 2 motor phases is to avoid wheel lockup when the inverter fails catastrophically. On a standard vehicle, it would lockup 2 front, or 2 rear wheels symmetrically, but on the plaid it would lockup a single wheel, and send the car in a violent spin.
Just watching this entire series from the time Sandy came on the scene has made me "engineering adjacent" so when I saw the inverter that could be put on there other vehicles I knew it was good engineering before Sandy said. You start to get a feel for it and it is NEVER BORING. Thanks so much for doing this, it's a lot of fun and I hope it will spark people going to school or looking to do something new to go into this field.
1:00 Hearing the emphasis and passion in @munro live voice gives me joy. I love engineering and this channel is one of the best. Much respect to Munro & the crew.
I just think back to 80s and 90s, when GM, Ford, and Chrysler would use the same inefficient, poorly-engineered drivetrain for a decade or more with practically no changes, to the point where new model years were purely cosmetic at best. Then here we have Tesla making radical improvements in countless areas on almost a monthly basis. They ditched the "Model Year" revision system and are innovating at warp speed.
@@BrowncoatFairy Tesla's models haven't changed much the last ten years, either. Just some cosmetics, massive software updates, and progressively higher capacity battery until 100 kWh.
@@paulmichaelfreedman8334 Didn't they introduce things like Superbottle and Octovalve midstream? Heat pump? Wiring improvements? And they apparently substituted all kinds of chips to work around recent shortages.
The carbon fiber overlap is wound under high tension to take stress off of the internal structure at high RPM. This is not easily achieved in biaxial or knitted sleeves. The CF overwrap also allows discontinuities in the magnet structure. Typically, the laminate has to hold everything together and that causes magnetic "short circuits" which reduce the available flux between the rotor and stator. B.T.W. "Tesla" is a unit of measure of magnetic field strength or flux density. It is only appropriate that their magnetic structures are strong!
15:10 Wow, straight poles. This type of magnet configuration enables higher BEMF and torque output. Skewing the magnet poles (whether on rotor or stator) is only to reduce the resonance, but it also reduces torque output. The pulsing/jittering can become a problem, but because it is spinning so fast, those spikes will be perceived by our biological sensors as a "HUMMM" in RMS (root mean square). If it is spinning slowly, I'm sure they are close looping with field oriented controls.
"close looping with field oriented controls" Does this involve using sophisticated software? That was my guess, Tesla is so good at using software to solve what used to be hardware problems.
@Olaf Willocx The magnets in the rotor are being pulled along by the changing electric field inside the motor. Peak torque happens when the magnet is perfectly positioned to stay synchronized with the wave. Slightly offsetting the magnets reduces problems with harmonics by making each magnet a little bit out of phase with the field, but also makes for less torque. Tesla apparently solved the harmonics problems, so now they can have all the magnets aligned and thus squeeze out maximum torque and power.
That was eye-opening as per usual. Of course, we were all waiting for the magnetic tricks in the rotor, and it didn't disappoint. But actually, what got to me first was the overall quality of the motor engineering. The castings, the finish on the bearing housings, the gears, the tolerances, it was all top notch quality and pushing the established boundaries.
Yes. If you change your mindset from engineering for autos to engineering for aerospace, then you can understand the gap. Tesla borrows the aerospace engineers from SpaceX and SpaceX borrows the manufacturing engineers from Tesla.
If I had a time machine, I would set the controls for an in person engineering / management discussion with Dr. Deming and our Sandy Monroe. Thanks for being you Sandy!
THANKS4GIVING Another Engineering Symphony. KUDOS to the TESLA ENGINEERS and SUPPORTING TEAMS. These achievements are so dam exciting THE FUTURE UNFOLDS.
I’m 80, when I was a kid, 1955 ish, my dad talked about the “ built in obsolescence in cars of the era”. The legacy auto makers are dragged, kicking and screaming attempting
Two thoughts about the small laminations that are inserted between the magnets and the air gap: 1. Their main function is not to keep the magnets in place but to conduct magnetic flux. If you were to swap them out for something the same shape but of a non-magnetic material, the motor would lose most of its torque. 2. All of the small laminations have a hole in them. As this doesn't help conduct magnetic flux, my bet is that these are there to stick little pins through to hold them in place during the winding process. The processes would be in this order: Insert little laminations as well as rotor + magnets on a fixture --> have all the outer parts of the fixture (pins holding little laminations) move radially inwards so the little laminations touch the magnets --> put this whole fixture with all the parts onto the winding machine.
The idea that parts are standardize is already a good thing for car fixing and modding enthusiate out there. Imagine down the line, you can buy a regular model 3 and buy a few piece of hardware for the motor to mod it into a Plaid? Or just buy individual parts and assemble a Tesla of your choosing like building a gaming computer? Damn.
Yes, designing universal assemblies that can be used in a variety of applications is customary practice in automotive engineering and elsewhere. Sandy usually disparages "parts bin" parts, but not when Tesla makes them. Having several versions of a board that are all labeled the same does seem highly questionable though.
You should see industrial inverters. In some models that have been using the same boards for everything from the smallest inverters to the biggest and have not changed anything for many years. They are very well understood so there is not much that you can improve other than getting better power switches. The other benefit of the warped rotor is that they get a stronger magnetic field from the same magnet by not having the steel that holds the small sections shorting the marketing field. The carbon wrap looks cool but there are better ways to achieve the same effect. The carbon wrap is also making the rotor less effecient by increasing the airgap between the rotor and the stator as carbon fibre is not magnetic.
@@Miata822 when Sandy refers to parts Bens.. He's referring to engineering around what's available. That's bad engineering. But to design something from the beginning to fit all models is great engineering. And for GM and Ford to use existing ice parts to build a super lightweight, efficient electric car it's a different animal.
Always awesome to watch you guys show how things work and how they’re made. I thought there was going to be a show and tell at the end of a new different way to wrap a stater
G'Day from Australia. Thanks so much for doing the Rotor Laminate sale. I got mine in the mail already and very happy to have a small piece of history. Keep up the amazing work!
Elon said the carbon sleeve has to be precisely woven ontop of the motor can’t be too lose or to tight. So I don’t think sandy’s idea would work, if I understood Sandy correctly
Sandy and team, it's too late for me (I'm 38), but I'd imagine these videos you guys have been putting out have inspired a lot of older kids/young adults in to want to pursue mechanical engineering and engineering in general and how exciting it can be.
2 mins into this and without a doubt this has been engineered by people that think about today, tomorrow and what has been done yesterday. This is my first look into the engineering of the Tesla or really any production EV for the consumer and I like what I see very much. I am excited to watch the rest.
Wow, 25% improvement in torque just with the new star shaped laminate. Carbon fiber wound wrap, and the strongest magnets they have tested. Unlike conventional car motors, there is no offset. I can see many competitors buying the full report on this part.
@@carholic-sz3qv You're kidding, right? The car is expensive, but not compared to automotive development budgets. Every manufacturer who is interested would have done this when the Plaid became available, without waiting for a crowdfunding campaign. And of course they don't advertise what they're doing. Tearing down competitor's vehicles has been normal practice for a long time, probably over a century.
@@brianb-p6586 yeah lol….. what’s the point of your argument actually!? They can teardown competitors vehicles but they don’t have to. I’m actually way more interested in the future and other brands for example have been using recycled fibers/plastics and many other composite materials. If everyone including tesla also used recycled materials in their cars it could have been more appealing tbh!
Just got my laminates signed by Sandy, thank you so much. I don’t want to say what I do for a living but this is very aligned with my job. The laminates are just a keepsake for me. I watch all your videos and hope to meet you and the team one day!
When you work with strong permanent magnets like this, you should get a set of titanium tools. This is common for the folks who work on MRI machines. Just a suggestion...
Judging by Sandy's enthusiasm, we're obviously getting to the juicy bits! Well Sandy, like you we're also sitting up and taking note! Many Thanks for making these video's for us to watch.
I disagree with Munro about the winding of carbon fibers. They are in the axis that matter, resisting centrifugal forces of the spinning rotor. Other direction would be wasted fibers. Furthermore, by winding the fibers they get pre-loaded and that way the rotor will withstand a lot of force before stretching out, while a jacket put on top will first stretch and then retain the magnet (maybe they could do a preloding by super cooling the rotor before insertion of the jacket ?)
You cannot disagree with an off the cuff first impression. Sandy is not saying anything that is set in stone, he is giving his real first impressions and that is why this channel is so good. It is sad to see these "ackchyually" posts. Maybe one of you read an electrek article on the carbon wrapped motor, but the bulk of these comments are just vapid people acting "smart" after reading someone else's comment and rewriting it. You wouldn't even know what you were looking at if a few people did not write non-technical articles on the carbon wrapped feature.
9:34 Interesting how the shape of the inverter casting, being from a cross-section of the Model 3/Y motor housing, is now used in transverse section on the side of the Plaid motor housing, but the shape still fits the surrounding features.
I think they got rid of the pulse with better control of the current with the inverter. The pulse is the action of the lines of rotor with those on the stator, if you control the current at the right time you can probably negate the pulse, a bit like they do with active noise cancellation. By getting rid of the source of the noise/vibration they probably get even more efficiency as they don’t need to offset the laminate anymore and they save money and complexity on the assembly line, genius!
A motor with clean sinusoidal three phase power has no pulsing. The power from each phase rises and falls with the voltage of each phase, but the sum of the three add up the same total power at every angle. Three phase generators in power stations are analogous - they don't pulse either. This is a property of three phase power.
@@dougtruesdell9937 Yes, but the armature is not, the discrete transition from metal to air gap in the stator interacting with the magnets in the stator will produce a ripple. I assumed that this was the cause of noise in EV motors as they probably all use high frequency PWM excitation in a sinusoidal pattern.
They also increased the gear ratio meaning the pulsing would increase. I wonder if the high frequency helps? Also the dual rear motors could have a slight phase shift between them. That might help cancel the pulsing and smooth out the current draw
I am surprised how much more strength they got of their magnets - the magnets are stronger - the rotor armature design make a stronger field - the rotor spin faster All together this will more than double the strength to weight ratio of the motor assembly and increase efficiency thus reducing the weight of the battery pack to get the same mileage. I hope their costing gets low enough to be able to put back all this tech into the model Y/3
@@carholic-sz3qv If 100g of rare earth save 50 Kg of battery and 2% of electricity at every charge for years that might be a good tradeoff. Those are all made up numbers, but what I mean is that they are tradeoffs and a few grams in a motor can have a big impact in other place. If the field is 2X stronger and the motor spin 2X faster, that mean 4X the power. That result in a 4X smaller motor and thus save weight, cost, battery size, and even rare earth. Elon talked about this phenomenon in a podcast about WW2. At some point the US made the spitfire 10% lighter with better quality aluminum, that mean they could also reduce the weight of wheels, the structure, the engine which resulted in additional performance and weight reduction. It’s a virtuous cycle of improvement.
@@alexforget unfortunately your point is totally wrong! 100g of rare earth doesn’t save 50kg or battery or any efficiency, the rare earths are used for more powerful magnets. Sandy showed the vw id.4 motor and said that It barely uses any rare earths. The efficiency is made in the whole car system from heat pumps to more aerodynamic shape…..
Defeating the need for a differential by having individually controlled computerized motors powering each rear wheel is probably the most genius engineering decision I’ve ever seen. Tesla engineers are absolutely brilliant!
Also, woven, ie non-unidirectional Carbon Fibre rotor wrap is a lot WEAKER, than the filament winding that they are doing for magnet retention. This is because with a filament wind more of you material is in the axis of the load (all the load is directed radially outwards by centripetal accel, there is no axial load) and because you can much more easily wind a single filament under tension. Tensile filament winding means the magnets are PRELOADED in compression when the machine isn't spinning , and only cross over into tension at some speed, this offset effectively raises the peak speed capability of the rotor by the offset compressive load! It's critical to have the thiniest magnet retention system possible, because the CF wrap is effectively adding to the air gap and hence reducing machine performance. Having a filament wind means you can run with a higher fibre to adhesive ratio, for the thinest possible layer.
To this day it just amazes me how Tesla engineering can be so superior to Ford and GM. I know people that work at Ford in Dearborn and GM in Toledo, and they still think and talk about Tesla like its not going to make it and that Ford and GM will catch up shortly. Great Video as always thank you both.
I spoke to a salesman at the old dodge dealer during the 08 recession and all the dealerships were closing. He didnt think they would close any dealerships either. The thing is denial is a really good way to cope with something that you cant stop and is about to put you out of a job, UNTIL your looking for a new one.
"think and talk" like you are winning, while ignoring evidence of failing defines American boys' math self concept: "I'm great at math! I won't do any math work (since it would reveal my low ability), but if I did do math, I'd be the best" My creators' research on failure-ignoring, math self-concept uncovers ego-protective thinking strategies that guarantee failure. "Boys" won't do math, so they can't.
@@carholic-sz3qv They can't? ruclips.net/video/RRbgChhJFCs/видео.html ruclips.net/video/B9vw2H-8ZQ4/видео.html ruclips.net/video/jhX3BmhJXc8/видео.html There are a few dozen other videos that say you're an idiot who doesn't know wtf you're talking about bruh.. should try this little thing called google before you spout nonsense in a public place.
Was going to order a laminate but $150 is too high of a price. I bought one from the Y teardown for $50 and that seemed more reasonable considering I wanted to support the channel.
My favorite video of yours was the Model Y vs. Mach-E Thermal comparison part 2, and my second favorite is whatever motor video I'm currently watching. I'm an EE but my skillset is miles away (networking chips) but the amount of detail you include in your videos is simply sublime. Thanks for making them.
Sandy, when you moved inverter from Plaid to Model 3, I started getting excited and by the time you finished Model Y rear, I was jumping in my living room. That is awesome and I'm just excited for no reason. I just don't know why. LOL!!!
As I remember Elon Musk described that the carbon sleeve requires certain tension to keep the rotor intact but not break the carbon fiber. The prefabricated sleeve might not work.
The only other way I have seen carbon sleeves applied is by press fitting with tapered rotors and sleeves. The sleeve was instrumented with strain gages. Then, the sleeve was pressed onto the rotor until the preload, indicated by the strain gage readings, was achieved. The sleeve was then trimmed to length on the rotor. The most effective high tension winding, that I have been part of, used high melt point thermoplastics as the resin/binder. This allowed the successive layers to be wound under high tension without displacing the underlying layers. Varying the tension as the sleeve builds thickness keeps the fiber radial stress equal so no layer loads up before another. Layers not sharing the load equally will result in sequential failure, like the trick used to tearing a phone book in half.
Motor design is IPM (Internal Permanent Magnet.) Where magnets are not directly at the surface but inside and where thne magnetic flux lines are concentrated to very precise O.D. area. This keep magnets far from the stator heat.
A calm, steady and focused on camera Sandy = BIG, AUDACIOUS surprises:) Team Sandy delivers again... just awesome content team and so thankful your company has chosen to share this way.. your team is absolutely inspiring the next generation of engineers.. or at a minimum annoying my daughter and her friends as I share your latest technology finding on my week to drive them to school:) (ps: yes, I bought one of those Sandy signed laminates.. can't wait for my week to drive the car pool!!)
Pretty sure that the magnets are magnetic when they are installed. The process by which the magnets are magnetised would not work on the full assembly as the whole assembly would become one unified magnet; and that's assuming that you could create a pulse of that size, power and penetration.
I don't know if they are or not, but I seem to remember when they took the model 3 motor apart, they made a point about how they had multiple pieces with alternating poles.
In my experience, the magnets are magnetized prior to being installed on the rotor. Attaching them to a rotor be a hair raising experience! I have seen adhesives, bolts, or dovetail type joints used to hold magnets before installing a sleeve to contain them when the rotor is spun up
Could it be that the rotor doesn't have offset laminations because there are two rear rotors? Cogging on one wheel is much less noticeable than when the rear is decoupled.
![Felix "Unfair" | [Stray Kids : SKZ-PLAYER]](http://i.ytimg.com/vi/Oswujxm2Ag0/mqdefault.jpg)
40 years engineering in big auto ICE, 20 years following EV development. Never thought Id see the day EVs would be allowed to reach their full potential let alone get a deep dive into the engineering. Thanks to Tesla for leading the vanguard and to Munro for letting us in on the detail. Done with skill full genuine enthusiasm transmitted on this brilliant channel, just the best 30 minutes.
1000%
15 years ago I had a RAV EV.
Everything that was bad about EV's back then was solved by Tesla. Features and devices and specs. Tesla made it practical, eventually no doubt, will make it affordable.
Thank you for your service!
Well said
The History of electric motors is just as extensive as that of the ICE if not more so
Rotor is wrapped under high tension, you can't just slide a sleeve over after the fact. You also have no need for multiple directions because 99% of the load is hoop stress from centrifugal forces. Knitting it would actually just make it weaker because the threads would have sharp bends in them.
I think Elon Musk explained it some time ago how complicated it was for them to make those fibers wrapped and how their engineering team came up with a unique method to do it in house.
You can heat the winding up and use thermal expansion to do the job. But I don't think epoxy can survive high temperatures.
Exactly. Can't slide it over because it's under extremely high tension. The whole point is to keep the motor from tearing itself apart at very high RPMs.
@@johntheux9238 You could alternetively shrink the inside with liquid nitrogen and slide it in then.
IM7 on a filament winding stand.
The carbon fiber layer is wound extremely tightly to prevent expansion at 20,000rpm. Sandy's recommended method would not provide the pre-load compression that is needed to maintain tolerance.
Actually it is wound under high tension, Tesla developed machinery in-house only for this process. And yes, the unidirectional winding serves the purpose to counteract centrifuge forces the best.
@@nilsfrederking62 Isn't that what I said?
exactly!.
True.
Additionally, since the carbon windings are there to stop the rotor from expanding outwards, they don't need to provide any sideways strength. So any sideways weaving would only be dead weight.
And any sideways weaving of the fibers equates to tiny bends, which would weaken the material.
I was quite frankly astounded that Sandy made a recommendation like this without researching the deep physics behind why the carbon fiber wrap. Quite an uncharacteristically flippant comment from him.
always smile when Sandy is happy about the engineering.
True
Yep me too
I think I deserve a bit of respect don't you think?
Rotor magnet skewing is nothing to do with physical torque pulsations that you can feel, because of the high effective rotor inertia and the high gear ratio between the rotor and the wheels, meaning the pulses, should they occur, happen far too rapidly to build into physical oscilationjs / vibrations.
What the skewing actually does is make the backEMF of the machine more sinusoidal, meaning the 5th and 7th harmonic of the fundamental drive frequency is a lower magnitude. If you drive the machine with basic FOC, then the output votlage waveform is sinusiodal, but the backEMF is a modified sine (with the 5th & 7th harmonic components as mentioned) which causes a current ripple. That current ripple not only reduces motor and inverter efficiency, causes a high frequency EMC emissions, cause perturbations in the FOC current control, but also prevent one from running as close as possible to the average power switch current limit (because the peaks would cross the limit when they occur). This is especially an issue with very low inductance machines, ie high power / hgh speeds ones of course.
What Tesla maybe doing is running with an active "feedforward" 5th and 7th harmonic cancelling voltage waveform, rather than relying on the axis current control to simply attempt to follow the backEMF. In effect, the inverter is actually now putting out a non-sinusoidal voltage waveform to match the non-sinusoidal waveform of machine!
Do this, right, and you get higher efficiency, more power, and can run closer to the utlimate limits of the system, and you can run with a significantly stiffer current control loop too.
The downside is your fundamental switching frequency needs to be high enough to be able to accurately synthesize this higher frequency voltage waveform, which requires faster and harder switching of your power elements, and a faster control loop to generate that waveform.
Do you think they use SiC inverters for that?
Another bonus of watching Munro vids. There are intelligent viewers watching and willing to shed additional light on things. Thank you. Honestly, I only understood the basic gist of your explanation, being a thumb smasher with only a bachelor's degree in "alternative" engineering.
Agree
You absolutely can feel cogging of electric motors in EVs that aren’t designed to avoid it. (At low speeds) the host of out of spec motoring points this out all the time.
I’m not qualified to disagree with or confirm anything else you said though. Sounds legit.
Wouldn't this mean the inverters are actually different than a model 3 version though?
THIS IS THE ONE BOYS AND GIRLS. THANK YOU SANDY!
On the carbon fiber winding, as close to radial as possible is the best. The filament winding industry calls this a “hoop” wind. With wet, or prepreg winding, the flow of the resin allows the individual fibers to nest into the previous layer’s surface. This makes the composite load up in unison as the rotor spins up.
Using a woven “sock” will not match the efficiency of the hoop wound sleeve. As the woven fibers cross each other, the fiber is bent, or kinked, as it crosses every opposite angled fiber.
thanks, fascinating
and a woven design might cut itself where the fibers cross. when pneumatic tires were invented they tried woven reinforcement. the tires kept blowing in 50 miles. they found the cords were cutting themselves where they cross. no tire has woven cords . each layer is parallel cords. granted in this rotor that may not happen but non 90 degree cords don't increase the strength and do prevent nesting.
Sandy responded to you ruclips.net/video/NsJgL9MSoIA/видео.html :D
@@ronblack7870 Is that the difference between old-style "crossply" tyres and "radials"?
Extra info! 👍
Without Munro we wouldn't have this much details explain...!! Kudos man
Am I the only one already fired up for the Cybertruck series? Thanks Munro, appreciate all your team does for the community!
Dillon, Seriously? There are at least a million of us that are fired up for the Cybertruck. 😃
I like the traditional design of the Ford and the Base Silverado. Stuck in my ways.
@@Dive-Bar-Casanova there’s room for everyone. My son would say “you do you”. I prefer “ to thine own self be true”. Cheers.
I can’t wait to see the unconventional Cybertruck torn down to it’s bare exoskeleton. It will fascinating to learn about the design, manufacturing techniques and materials used in the construction. Bring on the Cybertruck!
@@Dive-Bar-Casanova You like the planned obsolescence & inability to get usable parts from a scrappers, because the mountings are different between model years?... Or the electrical plug shape & pinouts using the exact same wires?... 🤦🏻
Guys HANDS DOWN... this is just incredible explanation and a good insight attention to details
Thank you!
Sandy - This is one of your greatest engineering videos. You and your company are just incredible!
Wow, thank you!
Agree this is a mile stone in history 👍 👏 wow
Come on Sandy, how about some 3D electromagnetics to show what that gaps between the ends of the T-caps and star points are doing to the flux?
Sandy, the tolerances are too tight to be able to slide over a carbon overwrap knitted. That's why it has to be applied directly to the spool under tension. Especially as the shaft expands and contracts under load and heat.
Correct. The fibers are wound under extreme tension. A cross-fiber knit would relax and not give the needed tension to keep the rotor from expanding at very high speeds.
@@edwardhart7252 exactly, because copper and carbon fiber have different rates of thermal expansion.
@@bobsbeard3977 There's no copper in the rotor. Yes, Musk talked about copper in a video about the rotor wrap, but he often doesn't know what he's talking about.
I believe that explosive disconnect was a lot more impressive than you may have realized as it happened way too fast to appreciate fully. If you pause the video at 24:39 and then move though it frame by frame, then the explosion was bight and visible in exactly three frames. If you are working with a computer keyboard you can go forward or backward one frame at a time. After you pause a video, pressing the PERIOD key moves the video forward one frame at a time and the COMMA key moves it backward one frame at a time.
Sure slowmo of explosives is always interesting, but what about why?? Seems to be a way "someone" can take control and bring your car to a stop at command. Please take the remote off switch out.
I did the frame-by-frame view (Thanks for the instructions) and count it as two frames with the explosion in them. Also when I kept advancing to watch the debris flying I notice that the frames come in identical pairs. So in postprocessing editing, the software doubled the number of frames to get the frame rate desired for uploading to RUclips. This means the explosion was only a single frame in the original video.
@@ryuuguu01 Thank you. Good to get input from someone knowledgable in video processing. Based on your more critical look at these frames it seems like the event was only really captured on just one frame - so lucky it was caught at all. It seems like the event was even quicker than I was led to believe.
On my MacBook, the flash occurs at 24:33 (24:33.53, actually, at an apparent 30 fps). It was visible in one frame only. Then in the replay, at 24:40.33 for two frames, still at 30 fps.
@@ryuuguu01 Next time rent a high speed Phantom camera which can shoot at thousands of fps. Then it may be more interesting to watch :)
I am an engineer ind the electronic industry (also worked in foundries, metal sheets etc.) for 20 years and a great fan of lean manufacturing - and I have to say that it is a great joy listen to you. Your are true experts with deep technical unterstanding. Bravo!
Great job Ben. You've quickly become relaxed on camera.
Ben Stein
best series on youtube atm
That inverter Phase bus bar pyro is VERY clever! It enables one to have a completely fail safe mode for a permanent magnet machine in the event of a loss of field control in the field weakening region (un-controlled regen ). It also cleverly uses HRC rated fuses to provide the final arc quenching, otherwise without those the severed section of bus bar would just arc across once opened by the pyro!
I don't quite get how that works. Does current flow only through the thin parts of the bars that are sheared off? If so, why are the bus bars so huge?
Yes I agree That's an excellent way of assuring safety with a permanent magnet motor capable of creating so much current... You can tell Tesla's big brother's SpaceX.
I was a bit surprised that they didn't secure the lugs as they would be in the assembly so that the pyro sees the stiffness it was designed to interact with.
@@w0ttheh3ll A large part of it goes through the thin part that gets sheared off with some going through the outer part that's left intact. That thin section is generating significantly more heat than the rest of the bus bar but it's solid copper directly attached to it so the heat is dissipated in the cooler parts of the rest of the bus bar. It's only necked down for a very short distance so the total resistance from the inverter to the windings is only negligibly more. The very clever part is how they shear it quickly enough to get it completely disconnected before the fuse for the outer part blows which is what actually disconnects power. High power fuses are a challenge to design and build because once there is an arc in air you only need a threshold amount of current to sustain the arc. DC applications are even more challenging because with AC you'll naturally pass through 0 amps 120 times a second for 60 Hz power which makes it much more likely to quench an arc. Inside the fuse you'll have stuff like the fuse wire being spiral wound to increase the length and it'll be filled with sand to help quench the arc and keep the energy released from just bursting the fuse apart like a tiny explosion.
By having the split bus bar they can use a fuse that doesn't need to carry large amounts of current, just be able to quench a dead short from 800V to ground at high fault currents. That's a lot easier to do when you only need to carry 50A during normal operation and 10kA in a fault. So long as the pyro can sever the normal current path before the fuse blows then you're not dealing with trying to quench that high power arc in open air or with a very large expensive fuse.
@@AndrewMerts Thanks for the explanation. So they can get away with a much smaller fuse because in normal operation, most of the current bypasses this fuse anyway?
placing that converter had such a satisfying and consistent "clunk " when inserted to the various models.
All of the LEGACY OEM EV are CLUNKY......LOL
@@markplott4820
yes mark, ...they are all "clunk'
Inverter*?
@@jacobstewart1155
"inverter", i lijke smrt people
I was totally impressed the circuit board was made to fit the housing. You got to love vertical integration.
Well thought out engineering very refreshing.
There was a lot of talking about quality issues in the past - mainly about aesthetic ones - but when you look at the quality of the components and manufacturing methods used Tesla tends much more to the higher end than other EV manufacturers. And of course the "symphony" of arranging the components is of the highest quality :-)
Yup, when people say Tesla has "poor build" it makes me angry. This is Ferrari was in its early days, cutting edge eng and motor design, but average 'body design'.
@@archigoel the difference being Tesla look and listen to issues, Ferrari didn’t, not even when Mr. Lamborghini had a simple solution for Ferrari’s poor clutch wear. Tesla definitely look to innovate on the basis of improvement rather than aesthetics. You know it’s a very good product when Sandy is so impressed he’s momentarily speechless 😂
At least visually, the build quality and engineering of Tesla’s running gear seems to be world class. Personally, I believe there is room for better quality of Tesla’s coachwork. If I had to pick one to have more refined engineering than the other, it would be the running gear, of course.
@@WEZ4136 - it's such a shock when people LISTEN !
They're not deaf at Tesla .
The carbon wrapped stator comes from rockets, let me explain. In rockets we use carbon over pressure vessels to make tanks, these are thin metal tank that are wrapped with thin strip of carbon fibre,
these can take pressures of 5000 psi. With the magnets in the motors trying to push away from each other using carbon fibre wrap makes sense so you can hold in the magnets even tighter. If you use a woven cloth then the seem becomes a weak point of failure which would cause the motor to explode, wrapping is the olny way they could do it.
You are right, from an industrial standpoint UD fiber is also cheaper and strips can be laid down robotically
I might be mistaken, but I believe the woven tube Sandy was talking about would have no seam. But, in my opinion, Sandy is incorrect and as mentioned in another post, the winding will be stronger.
Came from rockets, that came from... old steam cars. I recall at least one had its boiler wrapped in piano wire to enable it to hold a higher pressure.
I believe COPV's were initially designed for fire fighters.
@@winksaville The carbon needs to be wrapped under tension. The carbon itself is laid out on the tank in a criss cross pattern so it is very much like a woven cloth. have a look for "Making COPV" on youtube and you will see how it's done.
I'm so glad that Sandy and co could hangout with Tesla and SpaceX! I think that helps show Sandy how serious Elon is.... no other CEO is in the ballpark....
About the carbon fiber: the only meaningful stress is hoop stress, so wouldn't having a unidirectional wrap be the strongest solution?
Could you elaborate on that question? I think I see what you are saying. I'm not a material scientist tho
@@BillboVonPonce Sandy said they should use a woven wrap. Carbon fibers are only strong in tension. Woven wrap means it would be thicker and use more material but would be strong in both directions. However, this would make no sense here because the stress is only in one direction; the motor rotation is basically stretching outward at high speed. So Tesla's approach of just wrapping the fibers in this direction is better.
yes
Back in my boat design days....we used kevlar (aramid) for tensile strength and found carbon worked better than kevlar under compression.....
@16:15 a woven fabric doesn't make sense; the uni directional fibers are keeping it from expanding radially. they only need tension around the circumference, there's no bending forces on the rotor, nor any axial loads.
Pyro fuse on 2 motor phases is to avoid wheel lockup when the inverter fails catastrophically.
On a standard vehicle, it would lockup 2 front, or 2 rear wheels symmetrically, but on the plaid it would lockup a single wheel, and send the car in a violent spin.
Just watching this entire series from the time Sandy came on the scene has made me "engineering adjacent" so when I saw the inverter that could be put on there other vehicles I knew it was good engineering before Sandy said. You start to get a feel for it and it is NEVER BORING. Thanks so much for doing this, it's a lot of fun and I hope it will spark people going to school or looking to do something new to go into this field.
Another lesson in the fine art of education and entertainment for us who are inquisitive about the workings of new technology.
What I like about Munro is someone walking in on 6:35 he sees the camera and just smiles :)
1:00 Hearing the emphasis and passion in @munro live voice gives me joy. I love engineering and this channel is one of the best. Much respect to Munro & the crew.
Nice breakdown and comparisons, beautiful engineering from Tesla and great analysis by Munro and associates.
The first three minutes of this video says everything you need to know about Tesla. Thanks for pointing this important insight out.
Fascinating the kinds of innovations Tesla has made in only a short period of time.
fascinating why legacy auto with all those years of experience hasn't.
It's more like they took existing technology and maxxed it out unlike anyone or few ever did before.
I just think back to 80s and 90s, when GM, Ford, and Chrysler would use the same inefficient, poorly-engineered drivetrain for a decade or more with practically no changes, to the point where new model years were purely cosmetic at best. Then here we have Tesla making radical improvements in countless areas on almost a monthly basis. They ditched the "Model Year" revision system and are innovating at warp speed.
@@BrowncoatFairy Tesla's models haven't changed much the last ten years, either. Just some cosmetics, massive software updates, and progressively higher capacity battery until 100 kWh.
@@paulmichaelfreedman8334 Didn't they introduce things like Superbottle and Octovalve midstream? Heat pump? Wiring improvements? And they apparently substituted all kinds of chips to work around recent shortages.
The carbon fiber overlap is wound under high tension to take stress off of the internal structure at high RPM. This is not easily achieved in biaxial or knitted sleeves. The CF overwrap also allows discontinuities in the magnet structure. Typically, the laminate has to hold everything together and that causes magnetic "short circuits" which reduce the available flux between the rotor and stator.
B.T.W. "Tesla" is a unit of measure of magnetic field strength or flux density. It is only appropriate that their magnetic structures are strong!
This is the way
15:10 Wow, straight poles.
This type of magnet configuration enables higher BEMF and torque output.
Skewing the magnet poles (whether on rotor or stator) is only to reduce the resonance, but it also reduces torque output.
The pulsing/jittering can become a problem, but because it is spinning so fast, those spikes will be perceived by our biological sensors as a "HUMMM" in RMS (root mean square).
If it is spinning slowly, I'm sure they are close looping with field oriented controls.
"close looping with field oriented controls" Does this involve using sophisticated software? That was my guess, Tesla is so good at using software to solve what used to be hardware problems.
Do they have SiC inverters to enable some faster modulation strategies?
@Olaf Willocx The magnets in the rotor are being pulled along by the changing electric field inside the motor. Peak torque happens when the magnet is perfectly positioned to stay synchronized with the wave. Slightly offsetting the magnets reduces problems with harmonics by making each magnet a little bit out of phase with the field, but also makes for less torque. Tesla apparently solved the harmonics problems, so now they can have all the magnets aligned and thus squeeze out maximum torque and power.
They've been using FOC ESC's since the model 3. With motor being sensored, ofc.
@Olaf Willocx Saxon Lea is correct.
Thanks!
That was eye-opening as per usual. Of course, we were all waiting for the magnetic tricks in the rotor, and it didn't disappoint. But actually, what got to me first was the overall quality of the motor engineering. The castings, the finish on the bearing housings, the gears, the tolerances, it was all top notch quality and pushing the established boundaries.
Which is why Tesla is leagues ahead of any legacy auto manufacturer. I guess you could say Tesl was rocket spec.
Yes. If you change your mindset from engineering for autos to engineering for aerospace, then you can understand the gap. Tesla borrows the aerospace engineers from SpaceX and SpaceX borrows the manufacturing engineers from Tesla.
Agree 100%. These motors were designed for VERY long life.
If I had a time machine, I would set the controls for an in person engineering / management discussion with Dr. Deming and our Sandy Monroe. Thanks for being you Sandy!
LOL, I have to read all the comments because there is so much information in them that a layman(me) would not know. Amazing stuff, amazing channel
THANKS4GIVING Another Engineering Symphony. KUDOS to the TESLA ENGINEERS and SUPPORTING TEAMS. These achievements are so dam exciting THE FUTURE UNFOLDS.
Munro! Always on the cutting edge of information! Kudos!
I’m 80, when I was a kid, 1955 ish, my dad talked about the “ built in obsolescence in cars of the era”. The legacy auto makers are dragged, kicking and screaming attempting
Contd. attempting to hold onto short term profits. GM, Ford, VW, et al. , are the modern day Luddites.
The tight winding puts the force on the carbon fiber not the epoxy to hold it. 787 fuselage is made in a similar way.
Guess who worked on the 787?
@@rogerstarkey5390 Boeing?
😁
Two thoughts about the small laminations that are inserted between the magnets and the air gap:
1. Their main function is not to keep the magnets in place but to conduct magnetic flux. If you were to swap them out for something the same shape but of a non-magnetic material, the motor would lose most of its torque.
2. All of the small laminations have a hole in them. As this doesn't help conduct magnetic flux, my bet is that these are there to stick little pins through to hold them in place during the winding process. The processes would be in this order: Insert little laminations as well as rotor + magnets on a fixture --> have all the outer parts of the fixture (pins holding little laminations) move radially inwards so the little laminations touch the magnets --> put this whole fixture with all the parts onto the winding machine.
This is the big one!!! Can't wait to watch!
"For those who are not engineers, THIS is good engineering".
The idea that parts are standardize is already a good thing for car fixing and modding enthusiate out there. Imagine down the line, you can buy a regular model 3 and buy a few piece of hardware for the motor to mod it into a Plaid?
Or just buy individual parts and assemble a Tesla of your choosing like building a gaming computer? Damn.
Yes, designing universal assemblies that can be used in a variety of applications is customary practice in automotive engineering and elsewhere. Sandy usually disparages "parts bin" parts, but not when Tesla makes them.
Having several versions of a board that are all labeled the same does seem highly questionable though.
You should see industrial inverters. In some models that have been using the same boards for everything from the smallest inverters to the biggest and have not changed anything for many years.
They are very well understood so there is not much that you can improve other than getting better power switches.
The other benefit of the warped rotor is that they get a stronger magnetic field from the same magnet by not having the steel that holds the small sections shorting the marketing field. The carbon wrap looks cool but there are better ways to achieve the same effect. The carbon wrap is also making the rotor less effecient by increasing the airgap between the rotor and the stator as carbon fibre is not magnetic.
I’m not an engineer, but I sure did not need Sandy telling me that to know it is good engineering…
@@Miata822 when Sandy refers to parts Bens.. He's referring to engineering around what's available. That's bad engineering. But to design something from the beginning to fit all models is great
engineering.
And for GM and Ford to use existing ice parts to build a super lightweight, efficient electric car it's a different animal.
Thank you. I do think that Tesla has the wrapping part down well under control.
Thanks for showing us demonstrations alongside the explanations, I really enjoyed that!
The strength of the rotor carbon fiber does not need to be lateral. Using fiber spool winding is the correct solution.
Always awesome to watch you guys show how things work and how they’re made. I thought there was going to be a show and tell at the end of a new different way to wrap a stater
New game! You drink every time Sandy says “I’ve never seen anything quite like this”
How can humans come up with such incredible engineering when some others just want to destroy humanity? Amazing video! Thank You Munro!!
G'Day from Australia. Thanks so much for doing the Rotor Laminate sale. I got mine in the mail already and very happy to have a small piece of history. Keep up the amazing work!
Has anyone noticed the inverter boards are roughly made in the shape of the continental USA?
I was thinking that, too!
Hmmm, and those laminates are in the shape of a star of david
Shape is for function. Perhaps the USA's borders have been laid out for best inverter performance ?
Thanks
Thank you!
Elon said the carbon sleeve has to be precisely woven ontop of the motor can’t be too lose or to tight. So I don’t think sandy’s idea would work, if I understood Sandy correctly
It wouldn't work for lots of reasons.
If Sandy's idea has a seam, it could create a weak point.
MOTOR DAYYYYYYYYYYYYYYYYY!!!! The future is in your hands, and we are fortunate to get such an in-depth view of this magnificent technology.
Sandy and team, it's too late for me (I'm 38), but I'd imagine these videos you guys have been putting out have inspired a lot of older kids/young adults in to want to pursue mechanical engineering and engineering in general and how exciting it can be.
Whether you think you can or you can't you're right.
I know a number of great engineers who pursued degrees in their forties.
2 mins into this and without a doubt this has been engineered by people that think about today, tomorrow and what has been done yesterday. This is my first look into the engineering of the Tesla or really any production EV for the consumer and I like what I see very much. I am excited to watch the rest.
Wow, 25% improvement in torque just with the new star shaped laminate. Carbon fiber wound wrap, and the strongest magnets they have tested. Unlike conventional car motors, there is no offset. I can see many competitors buying the full report on this part.
Using more rare earths materials when other manufacturers are trying to use less of it lol…
Why? The technology is all apparent in a single still image, and those competitors bought and tore down their own Plaids long ago.
@@brianb-p6586 which “competitor bought and tored down the plaid!? No one! Stop lying.
@@carholic-sz3qv You're kidding, right? The car is expensive, but not compared to automotive development budgets. Every manufacturer who is interested would have done this when the Plaid became available, without waiting for a crowdfunding campaign. And of course they don't advertise what they're doing.
Tearing down competitor's vehicles has been normal practice for a long time, probably over a century.
@@brianb-p6586 yeah lol….. what’s the point of your argument actually!? They can teardown competitors vehicles but they don’t have to. I’m actually way more interested in the future and other brands for example have been using recycled fibers/plastics and many other composite materials. If everyone including tesla also used recycled materials in their cars it could have been more appealing tbh!
Thank You Munro And Associates! Such a unique opportunity for all. You to lead us through new tech. Lucky to have this.
At 13:35 they said they were going to show us some kind of sneak peek about the stator at the end of the video, did I miss it?
We all miss it.
Just got my laminates signed by Sandy, thank you so much. I don’t want to say what I do for a living but this is very aligned with my job. The laminates are just a keepsake for me. I watch all your videos and hope to meet you and the team one day!
When you work with strong permanent magnets like this, you should get a set of titanium tools. This is common for the folks who work on MRI machines. Just a suggestion...
Could also get non-sparking bronze tools. might be a little cheaper and harder wearing.
Judging by Sandy's enthusiasm, we're obviously getting to the juicy bits!
Well Sandy, like you we're also sitting up and taking note!
Many Thanks for making these video's for us to watch.
Outstanding videos! Can’t thank you guys enough for sharing your knowledge with the world!
I disagree with Munro about the winding of carbon fibers. They are in the axis that matter, resisting centrifugal forces of the spinning rotor. Other direction would be wasted fibers. Furthermore, by winding the fibers they get pre-loaded and that way the rotor will withstand a lot of force before stretching out, while a jacket put on top will first stretch and then retain the magnet (maybe they could do a preloding by super cooling the rotor before insertion of the jacket ?)
You cannot disagree with an off the cuff first impression. Sandy is not saying anything that is set in stone, he is giving his real first impressions and that is why this channel is so good. It is sad to see these "ackchyually" posts. Maybe one of you read an electrek article on the carbon wrapped motor, but the bulk of these comments are just vapid people acting "smart" after reading someone else's comment and rewriting it. You wouldn't even know what you were looking at if a few people did not write non-technical articles on the carbon wrapped feature.
9:34 Interesting how the shape of the inverter casting, being from a cross-section of the Model 3/Y motor housing, is now used in transverse section on the side of the Plaid motor housing, but the shape still fits the surrounding features.
I think they got rid of the pulse with better control of the current with the inverter.
The pulse is the action of the lines of rotor with those on the stator, if you control the current at the right time you can probably negate the pulse, a bit like they do with active noise cancellation.
By getting rid of the source of the noise/vibration they probably get even more efficiency as they don’t need to offset the laminate anymore and they save money and complexity on the assembly line, genius!
A motor with clean sinusoidal three phase power has no pulsing. The power from each phase rises and falls with the voltage of each phase, but the sum of the three add up the same total power at every angle. Three phase generators in power stations are analogous - they don't pulse either. This is a property of three phase power.
@@dougtruesdell9937 Yes, but the armature is not, the discrete transition from metal to air gap in the stator interacting with the magnets in the stator will produce a ripple.
I assumed that this was the cause of noise in EV motors as they probably all use high frequency PWM excitation in a sinusoidal pattern.
They also increased the gear ratio meaning the pulsing would increase. I wonder if the high frequency helps? Also the dual rear motors could have a slight phase shift between them. That might help cancel the pulsing and smooth out the current draw
Dang you some smart boys... Pretty cool 😎
Very intelligent people in these comments.
Thanks for taking your time to comment..
Greatly appreciate it.
I am surprised how much more strength they got of their magnets
- the magnets are stronger
- the rotor armature design make a stronger field
- the rotor spin faster
All together this will more than double the strength to weight ratio of the motor assembly and increase efficiency thus reducing the weight of the battery pack to get the same mileage.
I hope their costing gets low enough to be able to put back all this tech into the model Y/3
Or the CT or semi too! :)
I think the 3/Y performance is about to get a power boost. 670-800 hp? All it needs is the 2 long range motors.
Which means they have surely used a lot more rare earths compared to other manufacturers. Why can’t they reduce their use of rare earths!?
@@carholic-sz3qv If 100g of rare earth save 50 Kg of battery and 2% of electricity at every charge for years that might be a good tradeoff.
Those are all made up numbers, but what I mean is that they are tradeoffs and a few grams in a motor can have a big impact in other place.
If the field is 2X stronger and the motor spin 2X faster, that mean 4X the power. That result in a 4X smaller motor and thus save weight, cost, battery size, and even rare earth.
Elon talked about this phenomenon in a podcast about WW2.
At some point the US made the spitfire 10% lighter with better quality aluminum, that mean they could also reduce the weight of wheels, the structure, the engine which resulted in additional performance and weight reduction. It’s a virtuous cycle of improvement.
@@alexforget unfortunately your point is totally wrong! 100g of rare earth doesn’t save 50kg or battery or any efficiency, the rare earths are used for more powerful magnets. Sandy showed the vw id.4 motor and said that It barely uses any rare earths. The efficiency is made in the whole car system from heat pumps to more aerodynamic shape…..
What a privilege it is to get this kind of detailed breakdown of state of the art engines like this..
Defeating the need for a differential by having individually controlled computerized motors powering each rear wheel is probably the most genius engineering decision I’ve ever seen. Tesla engineers are absolutely brilliant!
I like seeing things that stay consistent and refined instead of scrapped and finding new problems in new designs the way other manufactures do.
I was so ready for this one to be an hour
I am not an engineer, but a bit of an energy nerd. And I have learned so much from these superb presentations. Thank you again, Sandy and crew!
Also, woven, ie non-unidirectional Carbon Fibre rotor wrap is a lot WEAKER, than the filament winding that they are doing for magnet retention.
This is because with a filament wind more of you material is in the axis of the load (all the load is directed radially outwards by centripetal accel, there is no axial load) and because you can much more easily wind a single filament under tension. Tensile filament winding means the magnets are PRELOADED in compression when the machine isn't spinning , and only cross over into tension at some speed, this offset effectively raises the peak speed capability of the rotor by the offset compressive load!
It's critical to have the thiniest magnet retention system possible, because the CF wrap is effectively adding to the air gap and hence reducing machine performance. Having a filament wind means you can run with a higher fibre to adhesive ratio, for the thinest possible layer.
the quality and workmanship is truly amazing, such smart engineering wow thank you sandy & Tesla
To this day it just amazes me how Tesla engineering can be so superior to Ford and GM. I know people that work at Ford in Dearborn and GM in Toledo, and they still think and talk about Tesla like its not going to make it and that Ford and GM will catch up shortly. Great Video as always thank you both.
I spoke to a salesman at the old dodge dealer during the 08 recession and all the dealerships were closing. He didnt think they would close any dealerships either. The thing is denial is a really good way to cope with something that you cant stop and is about to put you out of a job, UNTIL your looking for a new one.
"think and talk" like you are winning, while ignoring evidence of failing defines American boys' math self concept: "I'm great at math! I won't do any math work (since it would reveal my low ability), but if I did do math, I'd be the best" My creators' research on failure-ignoring, math self-concept uncovers ego-protective thinking strategies that guarantee failure. "Boys" won't do math, so they can't.
Superior! Lol….. yet a tesla can’t even tow!!!! Stfu!!!!
@@carholic-sz3qv They can't?
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There are a few dozen other videos that say you're an idiot who doesn't know wtf you're talking about bruh.. should try this little thing called google before you spout nonsense in a public place.
@@airheart1
That was awesome!
Thank you.
And, what a way to shut a brainwashed troll up.
brilliant, thanks Munro team
Love this channel! Sandy explains things so well, whats good and whats not - awesome.
Thanks Stephen
Great show, enjoyed the breakdown and seeing parts that are interchangeable
Mind blowing inverter compatibility.
I am a Tool and Die Maker + Engineer
When Sandy Monroe talk's you should Listen...
OUTSTANDING...
“Any sufficiently advanced technology is indistinguishable from magic "
Yay, Arthur C. Clarke!
めっちゃ👍言葉
And more specifically, it looks like magic to the people who don't understand it.
Great to see you at the shareholder event in Austin, Sandy! 👏
Was going to order a laminate but $150 is too high of a price. I bought one from the Y teardown for $50 and that seemed more reasonable considering I wanted to support the channel.
Ground up - big picture design. Love it!
My favorite video of yours was the Model Y vs. Mach-E Thermal comparison part 2, and my second favorite is whatever motor video I'm currently watching. I'm an EE but my skillset is miles away (networking chips) but the amount of detail you include in your videos is simply sublime. Thanks for making them.
Sandy, when you moved inverter from Plaid to Model 3, I started getting excited and by the time you finished Model Y rear, I was jumping in my living room. That is awesome and I'm just excited for no reason. I just don't know why. LOL!!!
Think on it.
I’m sure you can come up with a reason.
As I remember Elon Musk described that the carbon sleeve requires certain tension to keep the rotor intact but not break the carbon fiber. The prefabricated sleeve might not work.
Pretty sure it WOULD NOT work!
The only other way I have seen carbon sleeves applied is by press fitting with tapered rotors and sleeves. The sleeve was instrumented with strain gages. Then, the sleeve was pressed onto the rotor until the preload, indicated by the strain gage readings, was achieved. The sleeve was then trimmed to length on the rotor.
The most effective high tension winding, that I have been part of, used high melt point thermoplastics as the resin/binder. This allowed the successive layers to be wound under high tension without displacing the underlying layers. Varying the tension as the sleeve builds thickness keeps the fiber radial stress equal so no layer loads up before another.
Layers not sharing the load equally will result in sequential failure, like the trick used to tearing a phone book in half.
Total centrifugal force @ 16,000 rpm, r = 10cm (4 inches), 500g of magnet is 140t.
🙋♂️NOT AN ENGINEER AND I LOVE ❤️ THE IDEAS 💡 AND THANKS TO SANDY AND BEN FOR EXPLAINING IN TERMS A LAYPERSON CAN COMPREHEND 🤩🤩😍😍😍
Beautiful engineering analyses. Thanks Ben and Sandy!
Motor design is IPM (Internal Permanent Magnet.) Where magnets are not directly at the surface but inside and where thne magnetic flux lines are concentrated to very precise O.D. area. This keep magnets far from the stator heat.
I wish I could give 10,000 "thumbs up"
Great job Sandy and team!
Wonderful video, thanks Munroe and associates and thanks sabic!
But Sandy if you slide a knitted carbon over it how will you get it tight enough?
A calm, steady and focused on camera Sandy = BIG, AUDACIOUS surprises:) Team Sandy delivers again... just awesome content team and so thankful your company has chosen to share this way.. your team is absolutely inspiring the next generation of engineers.. or at a minimum annoying my daughter and her friends as I share your latest technology finding on my week to drive them to school:) (ps: yes, I bought one of those Sandy signed laminates.. can't wait for my week to drive the car pool!!)
Pretty sure that the magnets are magnetic when they are installed.
The process by which the magnets are magnetised would not work on the full assembly as the whole assembly would become one unified magnet; and that's assuming that you could create a pulse of that size, power and penetration.
I don't know if they are or not, but I seem to remember when they took the model 3 motor apart, they made a point about how they had multiple pieces with alternating poles.
In my experience, the magnets are magnetized prior to being installed on the rotor. Attaching them to a rotor be a hair raising experience! I have seen adhesives, bolts, or dovetail type joints used to hold magnets before installing a sleeve to contain them when the rotor is spun up
Those laminates look just like the Star of David. Please reserve one for me. Shalom!
Love being blown away with each video!! True appreciation of the marvelous engineering
'THE INVERTER'_____ I was on my head when l saw that move from motor to motor!
Could it be that the rotor doesn't have offset laminations because there are two rear rotors? Cogging on one wheel is much less noticeable than when the rear is decoupled.
I hadn't thought of that, but it's a good point - the left and right motors are skewed (randomly) from each other.
Mr. Munro you make real good job with your Team thanks for the great Video 👍👍👍