On the monoblock vs segmented magnets, I would recommend using magnaview film to see if the magnet is segmented inside of the external plating. The other thing to check is the electrical conductivity of the magnet to see if they added anything to the magnet that would reduce the electrical conductivity before sintering it. Both methods could be used to reduce eddy currents.
As I understand it, rare-earth magnets use sintered material (not poured into a mold in a liquid state). So perhaps a nonconductive binder (instead of sintering) is possible, in which case there would be no eddy losses on any axis. (The counterpoint is that such a structure would not benefit from being plated...so this may not be the case.)
@@satoshimanabe2493 the plating is typically alternating layers of nickel an copper and while I agree that eddy currents may be generated in the plating it is very difficult to build up eddy currents into very thin conductive sheets. I have spent a lot of time using induction power to evaporate metal in a vacuum chamber and bulk blocks are much easier to get thermal power into than thin conductive sheets. This is also why laminations are used. Lastly the plating would still be essential as Neodynimum based magnets are highly succeptialbe to moisture based corrosion.
@@patrickmorse7549 Thanks for the explanation about plating, very helpful. What I meant by non-sintered, seems it's actually called bonded magnets (I'm sure you're familiar). I was trying to say that if the bonding fully coats each particle so they are electrically isolated, would there be any need for additional segmentation?
I just love these Monro cybertruck reveal videos. I'm embarrassed to say they remind me of an old time burlesque show. Where each week the Cybertruck takes off a little bit more. Thank you for not playing bump and grind music.
@@MunroLive this outdated technology requires oil changes and liquid cooling just like combustion engines and its not 845 hp its 3 motors slapped together to equal 845 hp there are chevy small bocks pushing 900 hp naturally aspirated lol just ''one engine alone'' lol you call this superior tech? get real kids.
@@MunroLive look up louisville family celebrates 1 million miles it's a 2007 honda crv 3rd generation crv with honda k24/2.4 liter 4 cylinder with over 1 million miles lol so munros full of crap in this video.
Absolutely! Huge improvement for reliability/life cost. Some bearings have had pins/nubs on the outer race to prevent spinning and I've never understood why more of them don't.
It adds parts: the bearing rotation locking mechanism and the spring. Does not align with a "the best part is no part" philosophy. Should by constantly checked for better alternatives.
@@hybridinnovate Munro disassembled these very drive units including getting those bearings out. Why do you think this hinders repair of the units? Do you think, they broke the spring mechanism?
Dear Mr. Munro and Team, I wanted to extend my heartfelt appreciation for the incredible work you all have done in meticulously disassembling and analyzing the state-of-the-art machines. Tesla’s attention to details and dedication to refining their design and technology are truly remarkable. I was particularly fascinated by the hair-pin windings which I saw in some recent cars alternators. To me, they are a piece of art. No wonder why tesla is the ev-leaders, the mindfulness and understanding displayed by Tesla engineers in perfecting even the smallest details is truly commendable. Thanks
@@edwardfletcher7790 Yes! These teardowns are pure Tesla PR. The engineering is OK, but strikingly ordinary. A naive audience would be impressed by a mid 1950's automatic transmission, an ordinary ICE, a Timex mechanical watch... shiny stuff. Nothing in the Tesla is fundamentally different or better than all the cool stuff in any of the other electric cars, And most of those others have not had anywhere near as many troubling safety-related recalls: steering wheels that fall off, steering racks that are not mounted correctly, Cybertruck accelerators that jam, etc.
It's an interesting solution but... The tiny pin may prevent a small problem from quickly becoming a bigger one however at the power and torque levels involved once that bearing gets grabby its going to spin unless the operator notices the change in sound when it starts to fail and has it serviced expeditiously. Time will tell whether having that pin tear loose causes more damage than it prevents. Hopefully the MTBF of those bearings exceeds the half to one million mile operational life expectation of the vehicle. I can see that spring loaded pin failing and causing damage similar to other implementations using spring located pins that we've had for some time in pneumatic and hydraulic tools. If the damage isn't too catastrophic sometimes I've been able to just clean up the seating area and drill a new hole for the locating pin and spring while other times its weld and machine a new surface or replace that part of the housing depending on the cost of the part and the value of the unit or perhaps the cost of the downtime. Like Sandy said:. so anyways... ;> Best!
Great video, thank you so much for putting this for free! Some thoughts on the non segmented magnets: First of all, yes there are eddy current losses in the magnets but they are quite small compared to iron and copper losses. Still they can be problematic since they are the heat source in a temperature sensitive part. One problem with the segmentation is that you will lose some torque because of having less magnet material in the rotor. This will make the motor a bit less efficient. I think that this loss of efficiency could be more than the additional eddy current losses. However, these eddy current losses are mainly due to the current harmonics caused by the PWM. This means that you can drastically influence the magnet losses by the PWM. Maybe Tesla optimized their PWM in order to reduce the magnet losses for not having to segment the magnets.
It has nothing to do with what you are saying. It’s because this pm motor will never reach deep into the flux weakening region. If you are interested I can explain why I know.
I am no electrical engineer but Tesla uses segmented magnets in their other motors. There must be a valid reason why they changed. I remember a few years ago Sandy was surprised at segmented magnets used in the model 3 motor
I think its very likely that the inefficiency is only noticeable at high power loads, which it too infrequent to have an impact on range. The motor will have at least 300hp and will probably be using less than 60 at cruising speed.
SM> "That's not a guess, that is an engineering assumption" Sandy you are the best!!! A long way from the original front end teardown! LoL Thanks for another great teardown!
The disassembly intro adds context and perspective. If you were to add them to most of your videos we all would get a lot more out of them... THANKS!!!
That’s not the main point of cooling the magnets, this is a synchronous motor, it’s to prevent the motor from reaching the end region heating limit as well as armature heating limit as well as field current heating limit.
Its nice to finally see a company that cares to make the best product possible instead of designing products to fail for service revenue and profit motives. TESLA rules in that regard.!!
This kind of videos really benefits from Sandy outlining the wider meaning and historic place of all the technical details. As a software engineer I otherwise wouldn’t quite catch the showcased engineering genius 🙏🏻
@@markplott4820 Isn't that the truth. Especially when it comes to embedded design, it's easy to say "X" will work, then realize it doesn't in practice. Flashbacks to RS-232 vs RS-485 pain in the rear. Especially when the company is trying to be cheap.
Would love to see more of those big honking gears, that's some pretty wicked stuff. Machined, smooth, shiny metal - practical and beautiful all at once.
All motors can be "turned off" in motion; the difference between induction and PM is the magnetic drag while unpowered, as more clearly explained in another Munro video by Paul.
10:36 If you could confirm that endRings (rotor disks) are made of steel, reason of not covering up to the rotor OD would be to avoid magnetic short circuit (or flux leakage) on the mgnet lateral throught the disk. Of course, will also help to magnet cooling compared with a fully covered lateral rotor disks Induction machine rotor surface grooves have not been designed to replace skew. Seems that rotor slots are opened meaning that slot opening leakage inductance is reduced to get more power from the same voltage. Challenge there use to be to avoid any aluminum leakage during rotor cage casting process but seems that they have solved it. Great videos guys! You share with the world those hidden piece of engineering that we love to see!
@wethomas3 I love to see someone take a risk, innovate, move our perception into new direction. Ford made a lot of mistakes that cost the lives of many people before they dialed in their trucks. The issues you mention are minor. If you think you can do better, have at'er, I doubt you could compete.
@@toxic.lobster wait, you’re telling me that a stuck accelerator pedal (the reason for the recall) is “minor”? Fwiw I’m not a fan of Ford either buddy. But let’s be honest, Tesla while they innovate in areas they are shoddy compared to the rest of the industry in many others. iPads on the dash and faulty misnamed “FSD” systems aren’t impressive. Keep it 💯
"You'll never get that (half a million miles) engine life from an ice car." I'm real damn sure a couple of ICE cars have passed a million miles, not just half a million.
Better than spending a 100 grand on the Cybertruck monstrosity! I have almost 300,000 miles on my 4 cylinder Toyota 4 runner with the original engine and tranny and still runs great. New radiator, driveshaft with new u joints, tires, brakes, oil changes and that’s it! Parts are cheap. Let’s see a Tesla after 300,000 miles. If the battery goes tits up then take out a loan! I’m not anti EV but they have their place, we have a 2020 Chevy bolt which sees the majority of our miles now but it won’t replace our motorhome for travel or Chevy pickup for hauling.
@@richardwolf6269 There are plenty of Tesla's over 300K. Half a million is much tougher to hit, almost no on drives enough to do that on a vehicle before it way ages out. The avg yearly mileage for someone in the US is around 13.5K. That would be 37 years for the average person.
I think the magnets issue is so that tesla intentionally makes the motor hotter so that it can use that heat to keep the battery warm in colder weather. It is really the only motor that is running most of the time and especially on the highway. So, there is a lot of heat loss in colder climates. Basically, they don't have to add a heater, but then they can modulate the cooling for hotter climates, or even shift the work to the induction motors. I am just guessing, but I'm usually right.
I love induction motors! Such a indestructible design, soo easy to drive without all the position-sensing hall sensor junk. Makes me happy that they still use them even in modern electric cars
03 E220CDI , had over 1M Km and a original turbo on it's way out when my family got rid of it . Grandpa passed it down to my aunt and she traded it in for a 2016 BMW 3 series Gran Coupe. Car had literally 0 issues other than the loud turbo .
Even if they don't rebuilding or replacing an engine is still cheaper than a new battery half the time and it's not clear how many new batteries these cars would need to do that kind of mileage.
Civic reliability is absolutely phenomenal, the on of the few things beyond a civic is an early 2000s diesel Volkswagen Jetta, a million miles is common with those things. What year of civic do you have? I recall that the most (in fact the only) I could find of the Honda civics that were able to reach a million miles were all 2006.
The thick aluminum end plates on the PM rotor, if it is closer to the stator will have higher eddy currents that is not good for efficiency. If cooling is the reason why not have some holes on those end plates.?
Ok I know aluminum thermal conductivity but what is the comparison with air in this situation? I'm construction and thermal bridging of aluminum is tragic.😊
This locker allows both electric motors to send combined torque to the wheel that grips. Only really needed if a single motor has insufficient torque, which is a weakness in the PM reluctance rotor design.
The rotor end plates are called DE and ODE balance rings. DE is "Drive End" and ODE is "Opposite Drive End". You could get through rotor cooling to the magnets if you just perforated the balance rings. That's probably not the reason they aren't the same diameter as the lamination stack. Near net shape shafts were used in the GMT900 program as far back as 2008. We had a rotary hammer forge that fed our machining process.
Thanks! Wondering if the dual motor will have a similar set-up only reversing the PM with the induction motor. Also wondering if having the induction motor up front turned off at highway speeds would help with noise vs having the PM running all the time.
Induction and PM synchronous motors sharing stator design is good, but not new - Tesla has done that since their first PM motor, in the Model 3. Like the Model 3, the axial lengths are different, to suit different flux density and power requirements. Long before Tesla, Remy (now BorgWarner) offered their HVH series (which is also bar-wound with hairpins) with a choice of induction or PM rotors using exactly the same stator. It's good to see Tesla continuing this practice, and finally catching up to use bar winding.
Could it be that the magnet is segmented internally, inside the outer plating, or made of a less electrically conductive material to reduce eddy curent losses?
How much eddy current loss there is in a magnet though? Doesn't the stator aim to keep the magnetic field quite constant relative to the magnets, and a constant field definitely doesn't produce eddy currents!
you don't put an outer metal plating on a series of magnets. Thats magnets 101 man. Any metal solidly connected to the magnets would distort the mag field. You could segment the magnets, wrap in saran wrap, and then dip in liquid steel, like they dip snickers bars in chocolate, but that would increase the distance from magnetic material to the lectric coils it reacts with.... so you wouldn't do that.
@mikeselectricstuff , Wow, you would be a great addition to the Monroe reverse engineering team. I can hear your whispering voice now discussing the finer details as the components are carefully disassembled. I have been waiting for the day you disassemble an MRI superconducting magnet on your channel.
I assume they did something to the metallurgy of the permanent magnet. That would be a low hanging fruit. Tweak the silicon content or add some exotic element and bam eddy current is reduced significantly.
Love the bearing retention detail! Huge improvement for reliability/life cost. Some bearings have had pins/nubs on the outer race to prevent spinning and I've never understood why more of them don't.
The rambling about induction rotor construction starting around 19:07 is almost entirely incoherent. I think Sandy wanted to talk about skew, and stumbled into rotor construction as a result. In the end, the construction of the induction rotor for the Cybertruck motor is not described, and how longitudinal grooves might help motor operation is not explained. An induction motor's rotor uses electrical conductor windings which are shorted, so changing magnetic field from the stator induces a current in them, which produces the rotor's magnetic field. The windings can be constructed of wire, but that isn't done in EVs; instead, EVs use "squirrel cage" rotors, with a cage of lengthwise conductors which are shorted to each other at the ends. Regardless of how the conductors are made, the rest of the space is filled with a stack of iron laminations, just like a permanent magnet rotor for a synchronous motor. The old copper design has the conductor bars and one end plate expensively machined from a solid block of copper. The laminations are then stacked into it and the shaft, then the other end plate is attached to finish the rotor. The aluminum conductors of the newer design of rotor are cast into the spaces left for them in the stack of laminations. That means less waste material than machining from a block, and a less expensive manufacturing process; it also uses cheaper material (aluminum instead of copper).
The aluminium cage does have slightly greater resistance losses however. Maybe not a big deal, especially on a fast spinning motor because the Al conductors are lighter and could thus be thicker without causing issues with centrifugal stress.
14:50 Munro, are we sure there are significant eddy currents in a Permanent Magnet Synchronous Motor? The whole point of the word Synchronous is that the magnetic pole from the stator is rotating in phase with the rotor’s permanent magnetic field poles. If there is significant pole slipping (relative movement between stator and rotor) then I think there is a problem in design or control systems. Relative movement between the field and conductor is required for an eddy current.
We know heating is a problem that is why they opened up the end plate to get oil in. So there must be significant heating losses happening in the rotor near the magnets. Otherwise it would be much easier to fabricate the rotor all sealed up.
The magnetic field is still passed from pole to pole in the stator. Even when three or so poles overlap per winding, there is some field fluctuation passing through the rotor. So it's like amplitude modulation.
@rwhirsch Yes, but I think the reasons might not be instantly obvious. Is it simply cost savings? And is that simply to make the cars more affordable? Or cheaper to run? Or durability? Or better performance? And is that more power or greater efficiency? Tesla has greater integration in their engineering teams than anyone else, and I will bet there are many conversations that go, "Hey! I gained X% more something!" to which another engineer says, "Did you consider XYZ?" ...."Oh shit! Back to the drawing board" From which they end up with a third option that solves both problems. This is why I don't think many manufacturers are going to catch up all that quickly. Would love to see how the latest Mach-E compares to the first version. In particular the thermal management was a dog's breakfast. Even Ford admitted they missed an awful lot of details on the Mach-E generally.
Sandy and Co. = National Treasure. No I am wrong= International Treasure. (Though I can tell you as a multi plane owner in times past, Sandy, that aviation venture was doomed from the start. Nothing is tougher. You have balls to even have tried it.
At Investor Day in March 2023, Tesla announced that it planned to move away from rare earth metals in future motor designs. It would be interesting to hear if Tesla has managed to do this in the Cybertruck's motors.
12:00 The first time I saw Sandy was before the Pandemic, on Autoline After Hours. . . Showing John McElroy Tesla’s “Secret Sauce”, pulling a segmented magnet out of his tweed jacket.
I learn a lot from Munro, Tesla and others; Thanks! - With the Cybertruck I see a certain amount of over-engineering and a vehicle that no longer helps many people in their daily lives, and there is no blessing from Above. - On the other hand, useful vehicles for many people, in many regions and many terrains in the world, small and affordable, robust and simple, economical "Model 2" are needed! Small cars for 3, 4 or 5 people, with a length of 2.8m to 3.5m (!), that is my area of work and is on the rise. Because there are already enough big, expensive “dinosaur cars” that will die out, but the little clever things give the world hope.
These motor are also si.ilar to what will be going into the Semi. Electric food transport is more important than cheap car with the production available. Keep in mind typical US car makers take as long as tesla has been selling cars to develope a new model.
The segmented magnets make great sense if the truck is only operating in hot climates. But Tesla uses motor inefficiencies to generate heat to put into the heat pump that keeps the battery and cab warm. It may well be that when they run the calculations, the extra heat is required more often and the solid batteries allow this to be generated faster and at less electrical cost. Rapid warm up and keeping the battery warm is very important. Not to mention creature comfort.
Any news on the battery configuration? You wanted to look under the sides of the pack to look for more cells there and check the engineering assumption of 192s7p for the configuration of the pack.
More than just the non-segmented magnets, having that rotor end plate run to the rotor OD would generate unnecessary eddy current losses since they would be exposed to some of the magnetic flux from the stator field. In terms of the magnets, I'd be surprised if Tesla weren't on top of the gains segmented magnets can offer and I'd suspect they were not that significant, especially since the magnetic flux at part load operation is pretty modest compared with full torque so the losses would be not huge for most of the time.
Now apply those thoughts to 750,000 miles on said vehicle. What are the long term results? 1,250,000 miles? Keep in mind, the average Tesla produced after 2019 is expected to last 750k miles.
@@davidbeppler3032 I doubt Tesla is concerned with the cumulative efficiency losses above maybe 200K miles if they can save money up front in manufacturing costs.
@@davidbeppler3032the efficiency losses are probably only noticeable at higher power. For a vehicle that can do 0-60 in less than 3 seconds, it will spend very very little time at anywhere near full power.
@@davidbeppler3032 The efficiency won't change with time. It's all about selecting a cost-optimum design. If you spend 30 bucks more on segmented magnets but you can't see any range improvement and you can still handle the high power thermal control of the rotor, what's the point in spending the money?
04:18 Isn't it 10 bars per slot in the hairpin of the PM motor of CyberTruck? From what I can see on the video, there are 5 rows of end windings there.
Is the solid magnet for the motor the reason there is a pulsing vibration at some speeds? This is reminiscent of older automatic transmission when you are traveling at a speed that is kind of between two gears.
Because this America, and hp is the standard used by the general public to compare motor power. We use SAE wire guages in cars, and AWG guages for everything else. Those are standards in use. Engineers use the ISO standard for geographic position of only degrees, to five decimal places. And that's fine, but no navigators or cartographers use it. They use two different standards of degrees, minutes, and either decimal minutes, or seconds. Try to change standards. By all means.
@@lyfandethgreat for proving me right, you seem so confused ! 😮 Imagine this Tesla designed and built according to SAE NON METRIC standards (pre seventies) 😅 Thanks Ford who made the inch exactly 25.4 mm ! Imagine the mess if it was still based on the survey units ? As for the US general public , sad to compare its education level to the rest of the civilised world. I have a foot both sides of the pond.
Regarding the mechanical rear diff locking, why would that be needed when you have two servo-controlled motors with positional feedback? Surely they can simply command that they follow the same motion profile to come close to emulating a locked diff? The induction motors might not be quite as smooth as PM at low speed but I wonder why that wasn't done as it's a far cheaper solution, even if shaft resolvers of a higher resolution were needed? The bearing outer-race locking feature addresses a problem when over-sized ball-bearings are specified to handle helical-gear thrust loading, including cases where a tapered-roller pair would normally be used. It avoids the finicky preload setup on assembly but introduces a new problem because the minimum radial loading required to avoid outer-race spin in a slip-fit assembly situation is not achieved. This is a clever solution from Tesla as the spring pin even avoids needing to index the bearing during assembly. Thanks for the video, Munro team, alway interesting!
The reason is that when a wheel lifts off and traction is lost, a locked differential allows *_both_* electric motors to apply torque to the single tire.
@@redwood6737 good catch! I watched it again and you're correct that this was the front drive unit. They didn't show us the insides of the rear diff unit unfortunately.
@@KiwiMechEng thank you sir, I also got out the magnifying glass and when Sandy entered the picture they showed a spec sheet and on that sheet they’re showing 10,296 foot pound torque. The regular cyber truck there are actually showing 7435 Torque, not sure where they got those specs from but looks like they’re off by quite a bit. Not sure who did the misprint but I can’t imagine this Tesla putting out more than 1000 pounds of torque like my ram truck diesel Dooley Cummins.
I think Tesla is more like the 4th generation major design. BMW appears to be on the 2nd generation. Most others are on the first generation although able to get a few ideas from Tesla if they are smart. Cool to see everyone making design improvements.
@@MatthewDeveloper - It depends where you are and the charging network. Tesla superchargers are 100% renewable power from a combination of onsite resources and annual renewable matching. Those EV owners with home solar may also be 100% renewable today.
You may want to break open the nickel plating on those magnets in the cyber truck motor. Double check that they are rare earths because they may not be.
That’s already been revealed. Production decided to use an unauthorized lubricant to help with installation of the break pedal pad. While it did help speed up production it also makes it possible for the pad to slip. Good news is that it’s a simple fix to prevent going forward and to correct the few thousand they have produced so far.
I have wondered for a while, do you do any measurements on the gears? I have missed this being mentioned in the past. As a gear guy this interests me, I am so tempted to disassembly my tesla gear boxes to measure the gears.
Wow, the fact that they have to explain about how they are not going to get shocked. I didnt think that many people dont know about batteries and d/c power. Yes it can shock you but, its not like a/c in how easy you can get shocked.
Doesn't it require lots of maintenance to do that? Timing chains, value adjustments and replacements, spark plugs, rings, and more will need to be replaced along the way, multiple times. If you keep replacing enough parts it could go millions of miles, although nothing will be original.
Electric motors are awesome but what is the life expectancy of the battery which is the most expensive component? The million mile Tesla S had several motors and batteries replaced. Parts for many ICE vehicles are cheap and readily available. Teslas not so much so!
@@richardwolf6269 - Engines, Cataltyic converters, and timing chains are are not cheap either. Engines after 100K miles have reduced MPG too as the rings and valves wear and it starts burning oil. Battery packs generally don't really die, they just have less range over time, perhaps 80% of the original after 250K miles. Motors and packs keep getting better, but agree that for the very early Model S, getting a million miles will take a few packs and motors. The EV's "fuel" and maintenance savings are far more than those expense even on the early models.
@@richardwolf6269 cost waaay less than the ICE that get there. Keep in mind that many that get there as ICE it takes 25 or 30 years because it was was parked in a garage and drove at 45 mph. There are no ICE taxis with over 500k on them in a fleet. Bet Uber would find out they have a 100 model S with that on them if they asked the fleet.
Interesting that Tesla cheaped out on the motor magnets while also giving Cybertruck a smaller battery than other e-trucks. I think they're sandbagging on early Cybertrucks, not thinking Chevy would beat them on range by loading up a bigger battery pack. Perhaps sometime in or after 2025, Cybertruck will get a "refresh" with a bigger, better battery pack, and a few other tweaks to get real-world range over 350 miles without an extra battery.
That's good to know. For most car situations except maybe San Francisco street parking, the electric parking brake is probably fine. For hills and boat ramps, I want a more robust system to hold my vehicle.
@g6cpm6 I agree - a parking pawl in the front unit would be desirable (so all four tires hold), but I understand that they don't offer it because they can usually get away with just the parking brakes. It would also be technically viable to put parking brakes on the front, now that they are electrically applied, but no one does that... although Saab used to put the parking/emergency brakes on only the front, even though they were using mechanical cables back then.
I'd really like to understand why they do not go for a two motor configuration on the front, similar to the rear but two permanent magnet motors. Seems like this would eliminate the need for the mechanical differential and the associated differential lock mechanism as well as allowing full variable torque control rather than just an on/off lock.
@@brunoheggli2888Firstly,"You're" Secondly, a fair bit of Toyota's reliability reputation is because they reuse everything they can. At least, early on, many things in various cars were the same, in engineering terms, but repackaged for different vehicles. I'm not sure how much of that they still do, but it makes me wonder how much of that explains why they are doing so poorly building BEVs.
@@brunoheggli2888been doing it for decades until Tesla… Lexus and Toyota now is really the what u get compared to my legacy Camry in the 90s… nothing exciting
There is no need for segmented magnet in the rotor as there is no changing magnetic field. The rotor rotates and always aligned with the direction of the magnetic field.
Two questions. 1. Why front one is permanent magnet motor and rear ones are induction motors 2. Is induction motors are not difficult for speed control? How they are achieving synchronization between all these 3 motos? Amazing Engineering...
Induction motors are used only during high torque moments, and that typically is during hard acceleration. This load is desirable to place on the rear wheels. Each motor stator has its own dedicated variable frequency drive electronics and computer circuit board. They all are coordinated by the main computer.
20:57 "That's not really a guess, that's just an engineering assumption." 😂
That's a great weasel word, I'll have to use that someday.
So, an educated guess?
The term Sandy was grasping for is "Preliminary hypothesis".
@@revengefrommars its still a guess because they literaly have no idea lol...
we call them SWAG's ("Scientific Wild Ass Guess")
On the monoblock vs segmented magnets, I would recommend using magnaview film to see if the magnet is segmented inside of the external plating. The other thing to check is the electrical conductivity of the magnet to see if they added anything to the magnet that would reduce the electrical conductivity before sintering it. Both methods could be used to reduce eddy currents.
nah tesla wants to cost cut no matter what. Only the high margins matter now
@@NyashaMPatrick is referring to the testing methods to inspect the motor, nothing to do with Tesla making savings.
As I understand it, rare-earth magnets use sintered material (not poured into a mold in a liquid state). So perhaps a nonconductive binder (instead of sintering) is possible, in which case there would be no eddy losses on any axis. (The counterpoint is that such a structure would not benefit from being plated...so this may not be the case.)
@@satoshimanabe2493 the plating is typically alternating layers of nickel an copper and while I agree that eddy currents may be generated in the plating it is very difficult to build up eddy currents into very thin conductive sheets. I have spent a lot of time using induction power to evaporate metal in a vacuum chamber and bulk blocks are much easier to get thermal power into than thin conductive sheets. This is also why laminations are used. Lastly the plating would still be essential as Neodynimum based magnets are highly succeptialbe to moisture based corrosion.
@@patrickmorse7549 Thanks for the explanation about plating, very helpful. What I meant by non-sintered, seems it's actually called bonded magnets (I'm sure you're familiar). I was trying to say that if the bonding fully coats each particle so they are electrically isolated, would there be any need for additional segmentation?
Appreciate you included more of the teardown
I just love these Monro cybertruck reveal videos.
I'm embarrassed to say they remind me of an old time burlesque show. Where each week the Cybertruck takes off a little bit more.
Thank you for not playing bump and grind music.
It's good to hear Ben's voice in your video. I thought he was a good presenter and a real value to Munro Live.
We agree!
I like all the episodes, but a bit more in which Ben is presenting, good job, Ben 👍🏼🫡
@@ntulsianYes!
@@MunroLive this outdated technology requires oil changes and liquid cooling just like combustion engines and its not 845 hp its 3 motors slapped together to equal 845 hp there are chevy small bocks pushing 900 hp naturally aspirated lol just ''one engine alone'' lol you call this superior tech? get real kids.
@@MunroLive look up louisville family celebrates 1 million miles it's a 2007 honda crv 3rd generation crv with honda k24/2.4 liter 4 cylinder with over 1 million miles lol so munros full of crap in this video.
That bearing rotation constraint is most excellent !!
Absolutely! Huge improvement for reliability/life cost. Some bearings have had pins/nubs on the outer race to prevent spinning and I've never understood why more of them don't.
После разборки, совместить три подшипника будет не возможно, это сделано чтобы вы не смогли сделать ремонт
It adds parts: the bearing rotation locking mechanism and the spring. Does not align with a "the best part is no part" philosophy. Should by constantly checked for better alternatives.
@@hybridinnovate Munro disassembled these very drive units including getting those bearings out. Why do you think this hinders repair of the units? Do you think, they broke the spring mechanism?
@@MooseOnEarth это не мешает ремонту, позиционировать одновременно 3 подшипника для сборки будет не просто
Dear Mr. Munro and Team, I wanted to extend my heartfelt appreciation for the incredible work you all have done in meticulously disassembling and analyzing the state-of-the-art machines. Tesla’s attention to details and dedication to refining their design and technology are truly remarkable. I was particularly fascinated by the hair-pin windings which I saw in some recent cars alternators. To me, they are a piece of art. No wonder why tesla is the ev-leaders, the mindfulness and understanding displayed by Tesla engineers in perfecting even the smallest details is truly commendable. Thanks
STFU. TESLA IS GARBAGE
Hairpin motors have been around since at least the mid 1950s. Yes it looks very neat but is nothing new :)
Elon isn't going to read this or take it into account at your next HR assessment mate... LoL 🤣
@@edwardfletcher7790 Yes! These teardowns are pure Tesla PR. The engineering is OK, but strikingly ordinary. A naive audience would be impressed by a mid 1950's automatic transmission, an ordinary ICE, a Timex mechanical watch... shiny stuff. Nothing in the Tesla is fundamentally different or better than all the cool stuff in any of the other electric cars, And most of those others have not had anywhere near as many troubling safety-related recalls: steering wheels that fall off, steering racks that are not mounted correctly, Cybertruck accelerators that jam, etc.
@@kenfry2664 I'm glad someone else noticed the problems I did. The whole under carriage is a cleaning and rust prevention nightmare !!
that spring loaded pin to catch and stop outer race from spinning is so smart of an idea.. and Sandy's response "so anyways..." lol
It's an interesting solution but... The tiny pin may prevent a small problem from quickly becoming a bigger one however at the power and torque levels involved once that bearing gets grabby its going to spin unless the operator notices the change in sound when it starts to fail and has it serviced expeditiously. Time will tell whether having that pin tear loose causes more damage than it prevents. Hopefully the MTBF of those bearings exceeds the half to one million mile operational life expectation of the vehicle.
I can see that spring loaded pin failing and causing damage similar to other implementations using spring located pins that we've had for some time in pneumatic and hydraulic tools. If the damage isn't too catastrophic sometimes I've been able to just clean up the seating area and drill a new hole for the locating pin and spring while other times its weld and machine a new surface or replace that part of the housing depending on the cost of the part and the value of the unit or perhaps the cost of the downtime. Like Sandy said:. so anyways... ;>
Best!
Great video, thank you so much for putting this for free!
Some thoughts on the non segmented magnets: First of all, yes there are eddy current losses in the magnets but they are quite small compared to iron and copper losses. Still they can be problematic since they are the heat source in a temperature sensitive part. One problem with the segmentation is that you will lose some torque because of having less magnet material in the rotor. This will make the motor a bit less efficient. I think that this loss of efficiency could be more than the additional eddy current losses. However, these eddy current losses are mainly due to the current harmonics caused by the PWM. This means that you can drastically influence the magnet losses by the PWM. Maybe Tesla optimized their PWM in order to reduce the magnet losses for not having to segment the magnets.
Dont worry MUNRO will SELL the Cybertruck report for $1 MILLION Dollars.
It has nothing to do with what you are saying. It’s because this pm motor will never reach deep into the flux weakening region. If you are interested I can explain why I know.
I am @@ignaciohavok1
@@ignaciohavok1 I am interested, please explain!
@@ignaciohavok1sounds interesting, could you explain? Does it mean the motor is not driven to high speeds or is the corner speed quite high?
"It's not a guess. It's an engineering assumption." Best Sandy quote ever!
Aka Bullsh*tting lol
I am no electrical engineer but Tesla uses segmented magnets in their other motors. There must be a valid reason why they changed. I remember a few years ago Sandy was surprised at segmented magnets used in the model 3 motor
If loss of efficiency is the downside, it is possible that torque is the upside?
I think its very likely that the inefficiency is only noticeable at high power loads, which it too infrequent to have an impact on range. The motor will have at least 300hp and will probably be using less than 60 at cruising speed.
Trucks need MORE Torque than Speed .
more Efficiency over Acceleration.
more RANGE when Towing.
my best guess is that elon has 4 years backlog on the cybertruck. Now take that to its conclusion.........
@@davidanalyst671 No idea what you mean. What does the magnet has to do with the backlog?
SM> "That's not a guess, that is an engineering assumption"
Sandy you are the best!!!
A long way from the original front end teardown! LoL
Thanks for another great teardown!
The disassembly intro adds context and perspective. If you were to add them to most of your videos we all would get a lot more out of them... THANKS!!!
Cooling the magnets makes sense, because overheating a magnet can reduce it's strength permanently.
That’s not the main point of cooling the magnets, this is a synchronous motor, it’s to prevent the motor from reaching the end region heating limit as well as armature heating limit as well as field current heating limit.
Its nice to finally see a company that cares to make the best product possible instead of designing products to fail for service revenue and profit motives. TESLA rules in that regard.!!
This kind of videos really benefits from Sandy outlining the wider meaning and historic place of all the technical details. As a software engineer I otherwise wouldn’t quite catch the showcased engineering genius 🙏🏻
Software & Hardware need to work alongside on the Floor , to better understand one another.
@@markplott4820 Isn't that the truth. Especially when it comes to embedded design, it's easy to say "X" will work, then realize it doesn't in practice. Flashbacks to RS-232 vs RS-485 pain in the rear. Especially when the company is trying to be cheap.
Would love to see more of those big honking gears, that's some pretty wicked stuff. Machined, smooth, shiny metal - practical and beautiful all at once.
All motors can be "turned off" in motion; the difference between induction and PM is the magnetic drag while unpowered, as more clearly explained in another Munro video by Paul.
thank you for having sandy and other presenters in this one.
sandy makes the material watchable.
10:36 If you could confirm that endRings (rotor disks) are made of steel, reason of not covering up to the rotor OD would be to avoid magnetic short circuit (or flux leakage) on the mgnet lateral throught the disk.
Of course, will also help to magnet cooling compared with a fully covered lateral rotor disks
Induction machine rotor surface grooves have not been designed to replace skew. Seems that rotor slots are opened meaning that slot opening leakage inductance is reduced to get more power from the same voltage. Challenge there use to be to avoid any aluminum leakage during rotor cage casting process but seems that they have solved it.
Great videos guys! You share with the world those hidden piece of engineering that we love to see!
I love this truck even MORE now that I see the innards
I am DYING to see the electrical system. DYING!!!
Do you love it when they use soap to lubricate the accelerator pedal and have to recall every last truck due to suds left over? Lmao junk
@wethomas3 I love to see someone take a risk, innovate, move our perception into new direction. Ford made a lot of mistakes that cost the lives of many people before they dialed in their trucks. The issues you mention are minor. If you think you can do better, have at'er, I doubt you could compete.
@@toxic.lobster wait, you’re telling me that a stuck accelerator pedal (the reason for the recall) is “minor”? Fwiw I’m not a fan of Ford either buddy. But let’s be honest, Tesla while they innovate in areas they are shoddy compared to the rest of the industry in many others. iPads on the dash and faulty misnamed “FSD” systems aren’t impressive. Keep it 💯
@@toxic.lobsterit’s a high priced junk
"You'll never get that (half a million miles) engine life from an ice car."
I'm real damn sure a couple of ICE cars have passed a million miles, not just half a million.
Guy math: Spending $30,000 and countless hours to keep a $3,000 vehicle running. 😁
Stalin math: “Spending $60k ($30k + your labor) to get that lone $3k car to 1 M miles is a tragedy. Getting 1 M Teslas to 1 M miles is a statistic.”
Better than spending a 100 grand on the Cybertruck monstrosity!
I have almost 300,000 miles on my 4 cylinder Toyota 4 runner with the original engine and tranny and still runs great.
New radiator, driveshaft with new u joints, tires, brakes, oil changes and that’s it! Parts are cheap.
Let’s see a Tesla after 300,000 miles. If the battery goes tits up then take out a loan!
I’m not anti EV but they have their place, we have a 2020 Chevy bolt which sees the majority of our miles now but it won’t replace our motorhome for travel or Chevy pickup for hauling.
@@richardwolf6269 There are plenty of Tesla's over 300K. Half a million is much tougher to hit, almost no on drives enough to do that on a vehicle before it way ages out. The avg yearly mileage for someone in the US is around 13.5K. That would be 37 years for the average person.
Yeah there are a couple that have but that is the exception and not the norm. Less than 0.2% of vehicles on the road get to 500000
Kudos to Munro and associates - all your presenters are very experienced and do outstanding presentations. Excellent information and excellent naught.
I think the magnets issue is so that tesla intentionally makes the motor hotter so that it can use that heat to keep the battery warm in colder weather. It is really the only motor that is running most of the time and especially on the highway. So, there is a lot of heat loss in colder climates. Basically, they don't have to add a heater, but then they can modulate the cooling for hotter climates, or even shift the work to the induction motors. I am just guessing, but I'm usually right.
I love induction motors! Such a indestructible design, soo easy to drive without all the position-sensing hall sensor junk. Makes me happy that they still use them even in modern electric cars
I agree.
My Honda Civic at 460,000 miles says otherwise. I got that out of a piston car. It's more than doable if you regularly maintain.
Don’t confuse the cult with facts.
Elon could take a dump on a sidewalk and they would be clamoring to put it on their mantle! 🙄
03 E220CDI , had over 1M Km and a original turbo on it's way out when my family got rid of it . Grandpa passed it down to my aunt and she traded it in for a 2016 BMW 3 series Gran Coupe. Car had literally 0 issues other than the loud turbo .
Even if they don't rebuilding or replacing an engine is still cheaper than a new battery half the time and it's not clear how many new batteries these cars would need to do that kind of mileage.
Civic reliability is absolutely phenomenal, the on of the few things beyond a civic is an early 2000s diesel Volkswagen Jetta, a million miles is common with those things. What year of civic do you have? I recall that the most (in fact the only) I could find of the Honda civics that were able to reach a million miles were all 2006.
She's an 07 civic. Has all the paint issues, but mechanically absolutely sound.
The thick aluminum end plates on the PM rotor, if it is closer to the stator will have higher eddy currents that is not good for efficiency. If cooling is the reason why not have some holes on those end plates.?
air permittivity vs aluminum permittivity, good observation
Ok I know aluminum thermal conductivity but what is the comparison with air in this situation?
I'm construction and thermal bridging of aluminum is tragic.😊
little drill marks on the induction motor casting to maybe balance it like balancing a tire?
Yep. You'll see it on most (all?) motors.
So to be clear on the front differential- it's not limited slip, it's an electronic locker- giving a true Detroit locker type of performance?
This locker allows both electric motors to send combined torque to the wheel that grips. Only really needed if a single motor has insufficient torque, which is a weakness in the PM reluctance rotor design.
The supplier videos are excellent, the 3 D Services Group look to be extremely impressive.
Paul was really a great communicator in this video.
The rotor end plates are called DE and ODE balance rings. DE is "Drive End" and ODE is "Opposite Drive End". You could get through rotor cooling to the magnets if you just perforated the balance rings. That's probably not the reason they aren't the same diameter as the lamination stack. Near net shape shafts were used in the GMT900 program as far back as 2008. We had a rotary hammer forge that fed our machining process.
Thanks! Wondering if the dual motor will have a similar set-up only reversing the PM with the induction motor. Also wondering if having the induction motor up front turned off at highway speeds would help with noise vs having the PM running all the time.
The induction motor is noisier you have coil whine on the stator and the rotor while PM motors only have coils on the stator.
I believe I saw somewhere mention that on the 2 motor the induction is in the front and PM in the back.
Induction and PM synchronous motors sharing stator design is good, but not new - Tesla has done that since their first PM motor, in the Model 3. Like the Model 3, the axial lengths are different, to suit different flux density and power requirements. Long before Tesla, Remy (now BorgWarner) offered their HVH series (which is also bar-wound with hairpins) with a choice of induction or PM rotors using exactly the same stator. It's good to see Tesla continuing this practice, and finally catching up to use bar winding.
Could it be that the magnet is segmented internally, inside the outer plating, or made of a less electrically conductive material to reduce eddy curent losses?
How much eddy current loss there is in a magnet though? Doesn't the stator aim to keep the magnetic field quite constant relative to the magnets, and a constant field definitely doesn't produce eddy currents!
you don't put an outer metal plating on a series of magnets. Thats magnets 101 man. Any metal solidly connected to the magnets would distort the mag field. You could segment the magnets, wrap in saran wrap, and then dip in liquid steel, like they dip snickers bars in chocolate, but that would increase the distance from magnetic material to the lectric coils it reacts with.... so you wouldn't do that.
@mikeselectricstuff , Wow, you would be a great addition to the Monroe reverse engineering team. I can hear your whispering voice now discussing the finer details as the components are carefully disassembled. I have been waiting for the day you disassemble an MRI superconducting magnet on your channel.
I assume they did something to the metallurgy of the permanent magnet. That would be a low hanging fruit. Tweak the silicon content or add some exotic element and bam eddy current is reduced significantly.
Love the bearing retention detail! Huge improvement for reliability/life cost. Some bearings have had pins/nubs on the outer race to prevent spinning and I've never understood why more of them don't.
I really love this type of video. Thank you for sharing; it's very informative.
Glad you enjoyed it!
The rambling about induction rotor construction starting around 19:07 is almost entirely incoherent. I think Sandy wanted to talk about skew, and stumbled into rotor construction as a result. In the end, the construction of the induction rotor for the Cybertruck motor is not described, and how longitudinal grooves might help motor operation is not explained.
An induction motor's rotor uses electrical conductor windings which are shorted, so changing magnetic field from the stator induces a current in them, which produces the rotor's magnetic field. The windings can be constructed of wire, but that isn't done in EVs; instead, EVs use "squirrel cage" rotors, with a cage of lengthwise conductors which are shorted to each other at the ends. Regardless of how the conductors are made, the rest of the space is filled with a stack of iron laminations, just like a permanent magnet rotor for a synchronous motor.
The old copper design has the conductor bars and one end plate expensively machined from a solid block of copper. The laminations are then stacked into it and the shaft, then the other end plate is attached to finish the rotor.
The aluminum conductors of the newer design of rotor are cast into the spaces left for them in the stack of laminations. That means less waste material than machining from a block, and a less expensive manufacturing process; it also uses cheaper material (aluminum instead of copper).
The aluminium cage does have slightly greater resistance losses however. Maybe not a big deal, especially on a fast spinning motor because the Al conductors are lighter and could thus be thicker without causing issues with centrifugal stress.
well done guys... your channel is worth watching !! love.. Jazz from Auckland New Zealand
14:50
Munro, are we sure there are significant eddy currents in a Permanent Magnet Synchronous Motor?
The whole point of the word Synchronous is that the magnetic pole from the stator is rotating in phase with the rotor’s permanent magnetic field poles.
If there is significant pole slipping (relative movement between stator and rotor) then I think there is a problem in design or control systems.
Relative movement between the field and conductor is required for an eddy current.
We know heating is a problem that is why they opened up the end plate to get oil in. So there must be significant heating losses happening in the rotor near the magnets. Otherwise it would be much easier to fabricate the rotor all sealed up.
The magnetic field is still passed from pole to pole in the stator. Even when three or so poles overlap per winding, there is some field fluctuation passing through the rotor. So it's like amplitude modulation.
i assume at this point in the tesla story...if there's a design change or something that is "inexplicable" then it is for a damn good reason.
@rwhirsch Yes, but I think the reasons might not be instantly obvious. Is it simply cost savings? And is that simply to make the cars more affordable? Or cheaper to run? Or durability? Or better performance? And is that more power or greater efficiency? Tesla has greater integration in their engineering teams than anyone else, and I will bet there are many conversations that go, "Hey! I gained X% more something!" to which another engineer says, "Did you consider XYZ?" ...."Oh shit! Back to the drawing board" From which they end up with a third option that solves both problems. This is why I don't think many manufacturers are going to catch up all that quickly. Would love to see how the latest Mach-E compares to the first version. In particular the thermal management was a dog's breakfast. Even Ford admitted they missed an awful lot of details on the Mach-E generally.
Sandy and Co. = National Treasure. No I am wrong= International Treasure.
(Though I can tell you as a multi plane owner in times past, Sandy, that aviation venture was doomed from the start. Nothing is tougher. You have balls to even have tried it.
nope
Amazing the amount of power those little components on the inverter board’s control. The whole truck is awesome.
Yup mosfets can switch pretty insane current for their size. A chip the size of a fingernail can switch hundreds of amps❤
how does the grooves on the lamination of induction motor rotor cage eliminate torque ripple? and how is it better than skewed rotor?
It's not better just cheaper to fabricate. The grooves splits the magnetic fields.
I was taught that offset fins make the mechanical characteristics of the engine more "smooth"
Be interesting putting two of these motors in one vehicle 😀
At Investor Day in March 2023, Tesla announced that it planned to move away from rare earth metals in future motor designs. It would be interesting to hear if Tesla has managed to do this in the Cybertruck's motors.
_Extraordinary Engineering_
That was an engaging teardown boys! Can't wait for the next one....
12:00 The first time I saw Sandy was before the Pandemic, on Autoline After Hours. . . Showing John McElroy Tesla’s “Secret Sauce”, pulling a segmented magnet out of his tweed jacket.
I learn a lot from Munro, Tesla and others; Thanks! - With the Cybertruck I see a certain amount of over-engineering and a vehicle that no longer helps many people in their daily lives, and there is no blessing from Above. - On the other hand, useful vehicles for many people, in many regions and many terrains in the world, small and affordable, robust and simple, economical "Model 2" are needed! Small cars for 3, 4 or 5 people, with a length of 2.8m to 3.5m (!), that is my area of work and is on the rise. Because there are already enough big, expensive “dinosaur cars” that will die out, but the little clever things give the world hope.
YES!
These motor are also si.ilar to what will be going into the Semi. Electric food transport is more important than cheap car with the production available.
Keep in mind typical US car makers take as long as tesla has been selling cars to develope a new model.
Wonder if the front and rear inverter are all the same...I would imagine so...but surprised they didn't mention it.
this is just an amazing 20 minutes piece of knowledge. THANKS
Great info. Thank you to the whole team.
Our pleasure!
So does the dual motor configuration have two of the fronts that are in the cyber beast? Do we know that yet?
The rear motor on the dual motor model is a single configuration of the induction rear motors used here.
Heat can reduce or destroy magnetism. So cooling them may also increase magnet life/power.
The segmented magnets make great sense if the truck is only operating in hot climates.
But Tesla uses motor inefficiencies to generate heat to put into the heat pump that keeps the battery and cab warm.
It may well be that when they run the calculations, the extra heat is required more often and the solid batteries allow this to be generated faster and at less electrical cost.
Rapid warm up and keeping the battery warm is very important. Not to mention creature comfort.
Doesn't the aluminium shrink after being cast in the rotor? I imagine you'll have some gaps and resistances. Maybe also adding noise?
Any news on the battery configuration? You wanted to look under the sides of the pack to look for more cells there and check the engineering assumption of 192s7p for the configuration of the pack.
I smacked the "Like" button !
thanks Munro team!
Thank you for educating us, great content!
More than just the non-segmented magnets, having that rotor end plate run to the rotor OD would generate unnecessary eddy current losses since they would be exposed to some of the magnetic flux from the stator field. In terms of the magnets, I'd be surprised if Tesla weren't on top of the gains segmented magnets can offer and I'd suspect they were not that significant, especially since the magnetic flux at part load operation is pretty modest compared with full torque so the losses would be not huge for most of the time.
Now apply those thoughts to 750,000 miles on said vehicle. What are the long term results? 1,250,000 miles? Keep in mind, the average Tesla produced after 2019 is expected to last 750k miles.
@@davidbeppler3032 I doubt Tesla is concerned with the cumulative efficiency losses above maybe 200K miles if they can save money up front in manufacturing costs.
@@davidbeppler3032the efficiency losses are probably only noticeable at higher power. For a vehicle that can do 0-60 in less than 3 seconds, it will spend very very little time at anywhere near full power.
@@davidbeppler3032 The efficiency won't change with time. It's all about selecting a cost-optimum design. If you spend 30 bucks more on segmented magnets but you can't see any range improvement and you can still handle the high power thermal control of the rotor, what's the point in spending the money?
Great video and I hope your hands getting better love the work you’ve been doing in that area too
15:00 Land Cruiser 70 series : "Hold my beer Sandy" 😂😂😂 (just one example that they can)
Just as a clarification. When you say "noise". You are talking about electromagnetic noise?
04:18 Isn't it 10 bars per slot in the hairpin of the PM motor of CyberTruck? From what I can see on the video, there are 5 rows of end windings there.
Is the solid magnet for the motor the reason there is a pulsing vibration at some speeds? This is reminiscent of older automatic transmission when you are traveling at a speed that is kind of between two gears.
This *has* to be watched at 1.5 playback speed. The anticipation was killing me.
AMAZING! THANKS FOR VIDEO!
Power is in Watt, why still use these archaic HP ? And which one ? The one = 746W ? Same for torque, Nm etc...
Because this America, and hp is the standard used by the general public to compare motor power.
We use SAE wire guages in cars, and AWG guages for everything else. Those are standards in use.
Engineers use the ISO standard for geographic position of only degrees, to five decimal places. And that's fine, but no navigators or cartographers use it. They use two different standards of degrees, minutes, and either decimal minutes, or seconds.
Try to change standards. By all means.
@@lyfandethgreat for proving me right, you seem so confused ! 😮
Imagine this Tesla designed and built according to SAE NON METRIC standards (pre seventies) 😅
Thanks Ford who made the inch exactly 25.4 mm ! Imagine the mess if it was still based on the survey units ?
As for the US general public , sad to compare its education level to the rest of the civilised world. I have a foot both sides of the pond.
Are you going to complain when they start using Electric HP or do you know if they are?
Excellent video.
Thank you very much!
Regarding the mechanical rear diff locking, why would that be needed when you have two servo-controlled motors with positional feedback? Surely they can simply command that they follow the same motion profile to come close to emulating a locked diff? The induction motors might not be quite as smooth as PM at low speed but I wonder why that wasn't done as it's a far cheaper solution, even if shaft resolvers of a higher resolution were needed?
The bearing outer-race locking feature addresses a problem when over-sized ball-bearings are specified to handle helical-gear thrust loading, including cases where a tapered-roller pair would normally be used. It avoids the finicky preload setup on assembly but introduces a new problem because the minimum radial loading required to avoid outer-race spin in a slip-fit assembly situation is not achieved. This is a clever solution from Tesla as the spring pin even avoids needing to index the bearing during assembly.
Thanks for the video, Munro team, alway interesting!
The reason is that when a wheel lifts off and traction is lost, a locked differential allows *_both_* electric motors to apply torque to the single tire.
It seem to me that locker mechanics was in the front permanent magnet motor section. I could be wrong.
@@redwood6737 good catch! I watched it again and you're correct that this was the front drive unit. They didn't show us the insides of the rear diff unit unfortunately.
@@KiwiMechEng thank you sir
@@KiwiMechEng thank you sir, I also got out the magnifying glass and when Sandy entered the picture they showed a spec sheet and on that sheet they’re showing 10,296 foot pound torque. The regular cyber truck there are actually showing 7435 Torque, not sure where they got those specs from but looks like they’re off by quite a bit. Not sure who did the misprint but I can’t imagine this Tesla putting out more than 1000 pounds of torque like my ram truck diesel Dooley Cummins.
Amazing what EV’s have done with just first generations. Just think a few more generations. Battery tech is also rapidly changing
I think Tesla is more like the 4th generation major design. BMW appears to be on the 2nd generation. Most others are on the first generation although able to get a few ideas from Tesla if they are smart. Cool to see everyone making design improvements.
Some of the Chinese are on the 2nd and 3 generations as sell.
Charging infrastructure that's not based on coal or diesel is also growing, we're not there yet, but it sure is coming.
@@MatthewDeveloper - It depends where you are and the charging network. Tesla superchargers are 100% renewable power from a combination of onsite resources and annual renewable matching. Those EV owners with home solar may also be 100% renewable today.
You may want to break open the nickel plating on those magnets in the cyber truck motor. Double check that they are rare earths because they may not be.
Ben's explanations have been awesome! Thanks to both! 👏👏😍😍
Is installing two electric motors a better solution than one motor with an adaptive/adjustable differential?
Awesome wideo! Thanks for sharing knowledge!
Greetings from Poland!
Why aren’t the segmented magnets in a halbach array?
A Halbach array is valuable in a surface-mounted configuration, but not in an interior (embedded) configuration like this.
Sandy is the man.
Really thanks sir ,god bless you and your family
The motor is a work of art
))) у вас плохой вкус. Это произведение маркетологов.
Great video as always!
What about the accelerator pedal recall?
It would be nice if you could show what is the issue
That has nothing to do with the drive units so it's not relevant to this video... and it's just a loose pedal cover.
That’s already been revealed. Production decided to use an unauthorized lubricant to help with installation of the break pedal pad. While it did help speed up production it also makes it possible for the pad to slip.
Good news is that it’s a simple fix to prevent going forward and to correct the few thousand they have produced so far.
Seems to me that the pedal cover issue caused a backlog of Cybertruck to build up in the Austin GF parking lots long before this became public.
I wonder if the rear door hinges can be moved to the front doors
Terrific overview.
thank you sandy n team
I bet Munro's about to sell a whole lot of Cybertruck teardown reports once this series is finished.
Hope so
Only by Munro... thx folks for the teardown and comments, this info is priceless both for existing and future EV owners. Keep on building great name!
So the inverter on the motor is used for recharging during decel?
What do you think is causing the stuck pedal issue with the cybertruck?
I have wondered for a while, do you do any measurements on the gears? I have missed this being mentioned in the past. As a gear guy this interests me, I am so tempted to disassembly my tesla gear boxes to measure the gears.
Они достаточно массивные )))
Could the rear motor be split and used as 2 motors in a different application or do they need to be interlinked (using a different controller)
Wow, the fact that they have to explain about how they are not going to get shocked.
I didnt think that many people dont know about batteries and d/c power.
Yes it can shock you but, its not like a/c in how easy you can get shocked.
“Piston car can’t go 3/4 million miles,,,,,” 30 years ago Lexus causally makes the LS400 which can go over million miles 🤯
Doesn't it require lots of maintenance to do that? Timing chains, value adjustments and replacements, spark plugs, rings, and more will need to be replaced along the way, multiple times. If you keep replacing enough parts it could go millions of miles, although nothing will be original.
Electric motors are awesome but what is the life expectancy of the battery which is the most expensive component?
The million mile Tesla S had several motors and batteries replaced.
Parts for many ICE vehicles are cheap and readily available. Teslas not so much so!
@@richardwolf6269 - Engines, Cataltyic converters, and timing chains are are not cheap either. Engines after 100K miles have reduced MPG too as the rings and valves wear and it starts burning oil.
Battery packs generally don't really die, they just have less range over time, perhaps 80% of the original after 250K miles. Motors and packs keep getting better, but agree that for the very early Model S, getting a million miles will take a few packs and motors. The EV's "fuel" and maintenance savings are far more than those expense even on the early models.
@@richardwolf6269 cost waaay less than the ICE that get there. Keep in mind that many that get there as ICE it takes 25 or 30 years because it was was parked in a garage and drove at 45 mph.
There are no ICE taxis with over 500k on them in a fleet.
Bet Uber would find out they have a 100 model S with that on them if they asked the fleet.
Interesting that Tesla cheaped out on the motor magnets while also giving Cybertruck a smaller battery than other e-trucks. I think they're sandbagging on early Cybertrucks, not thinking Chevy would beat them on range by loading up a bigger battery pack. Perhaps sometime in or after 2025, Cybertruck will get a "refresh" with a bigger, better battery pack, and a few other tweaks to get real-world range over 350 miles without an extra battery.
Is there a parking pawl in either motor? Both? For slippery coastal boat ramp use, I need to be able to lock all 4 wheels in park.
I don't think Tesla puts a parking pawl in any drive unit. It relies on the parking brakes, which are only on the rear wheels.
That's good to know. For most car situations except maybe San Francisco street parking, the electric parking brake is probably fine. For hills and boat ramps, I want a more robust system to hold my vehicle.
@g6cpm6 I agree - a parking pawl in the front unit would be desirable (so all four tires hold), but I understand that they don't offer it because they can usually get away with just the parking brakes.
It would also be technically viable to put parking brakes on the front, now that they are electrically applied, but no one does that... although Saab used to put the parking/emergency brakes on only the front, even though they were using mechanical cables back then.
I'd really like to understand why they do not go for a two motor configuration on the front, similar to the rear but two permanent magnet motors. Seems like this would eliminate the need for the mechanical differential and the associated differential lock mechanism as well as allowing full variable torque control rather than just an on/off lock.
Which is cheaper, a diff or a whole motor?
The PM motors are very expensive, also you probably get more power than the tires can handle, so minimal benefit. Rivian does quad motor though.
@@EwanM11 Well, yes, but you solve both problems by making each motor half as powerful!
@@john_hind half the power will not half the cost.
@@EwanM11 Electric motors do scale fairly well cost to torque. Possibly the reason is you do want to be able to route all the torque to one wheel.
When engineers sound like a kid in a candy shop. Buy it.
lol......
Just buy a Toyota and your fine!
@@brunoheggli2888 Toyota is pretty impressive tech... For 20 years ago. I don't suggest buying a Toyota. They'll go bankrupt in the next 10 years.
@@brunoheggli2888Firstly,"You're" Secondly, a fair bit of Toyota's reliability reputation is because they reuse everything they can. At least, early on, many things in various cars were the same, in engineering terms, but repackaged for different vehicles. I'm not sure how much of that they still do, but it makes me wonder how much of that explains why they are doing so poorly building BEVs.
@@brunoheggli2888been doing it for decades until Tesla… Lexus and Toyota now is really the what u get compared to my legacy Camry in the 90s… nothing exciting
There is no need for segmented magnet in the rotor as there is no changing magnetic field. The rotor rotates and always aligned with the direction of the magnetic field.
segmented and hall effect magnets can juice a couple percentage points of efficiency out of the motor.
@@davidanalyst671What if they fiddled with the permanent magnet alloy to reduce eddy currents?
@@kazedcat I'm not an engeener but I can guarantee that would cost more than just doing the segmented magnets.
@@sparksmcgee6641 One time cost on developing the alloy compared to a reoccurring cost of adjoining segmented magnets.
Just a question regarding the aluminum battery wire: why can't it also be stamped and then isolated?
What is the issue with just bending the concentric assembly? I don't see any downside.
Two questions.
1. Why front one is permanent magnet motor and rear ones are induction motors
2. Is induction motors are not difficult for speed control? How they are achieving synchronization between all these 3 motos?
Amazing Engineering...
Induction motors are used only during high torque moments, and that typically is during hard acceleration. This load is desirable to place on the rear wheels.
Each motor stator has its own dedicated variable frequency drive electronics and computer circuit board. They all are coordinated by the main computer.
@@imconsequetau5275 thanks!
Great piece of Engineering?!
Great craftsmanship.