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Tesla Model 3 Torn Down, Hacked and Set On a Dynamometer, Exposing Unusual Tech Details (electrek.co)
Rei writes: With an estimated 8,670 Model 3s delivered, a race is on as competitors and owners work to figure out its limits and explore the tech behind it. Many-time Tesla teardown expert "Ingineerix" has posted a series of videos and discussed his findings on Reddit. Among them: what appears to be the industry's first switched reluctance motor, a massive "smuggling compartment" allocated for a future front-wheel motor, no physical fuses (all solid-state), significant wiring harness length reductions via the use of multiple body controllers, a swappable crash energy absorption system, a liquid-cooled compute unit, and redundant controllers for all safety-related systems. He followed up by posting a screenshot of the car tricked into "factory mode" to reveal its internal specs, including a 1200A max discharge current, 370kW max discharge power, and a 76 kWh pack with 72,5kWh usable. Meanwhile, Munro and Associates tore down a Model 3 for an undisclosed, "not Tesla" client, releasing a video criticizing its build quality and for difficulty in accessing the HV cables in the event of an accident (Munroe's claims were dismissed by Ingineerix). Meanwhile, engineers from German automakers were extremely impressed by what they found during their teardown -- particularly the power electronics system, which they described as "compact, expandable, fully integrated, modular, easily accessible, well-protected, reasonably priced and astonishingly clever in many details." Other owners have been putting their cars on dynamometers to measure their power. Drag Times suffered some skid and measured a conflicting 281 / 327.6 hp with 552 lb-ft torque. Contrarily, Tesla Repair Channel found consistent readings around 250hp when starting from 30mph, but consistently around 390 hp when starting from 10mph. The reason for the discrepancy is not yet clear.
To expand a bit on the motor: it should be clarified that it's not a normal switched reluctance motor (SRM), but rather a PMSRM (permanent magnet switched reluctance motor).
Reluctance is used to some extent in many hybrid EV motors, in the form of "IPM" - interior permanent magnet motors. These are a hybrid of a conventional surface permanent magnet motor (SPM) and a SRM, allowing for high power at high speeds that SPMs don't allow for, as well as reducing magnet sizes (and thus rare earth consumption). By contrast, a PMSRM is a SPM that incorporates permanent magnets into the stator; they don't move and are readily cooled, while sculpting and enhancing the field to increase torque density and help control torque ripple.
It's a new type of motor, combining extreme efficiency, high torque density, and reliability over that offered by an IPM. Getting a PMSRM to work smoothly is an impressive job.
Point of interest. Offering to shoot us might not work so well as an incentive as you might imagine.
Can't wait to see a teardown of the Tesla Roaster, I heard Elon put it somewhere safe though.
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I have to say, that between Tesla and SpaceX Musk seems to truly be amazing for at least one thing - hiring engineering talent.
Sure Tesla has some struggle scaling up producing. But a lot of what they have built is really advanced technically, and generally works quite well.
SpaceX is even more amazing in terms of tech, getting stuff working like vertical landings that seemed like it was going to remain as science fiction, while also seeming to be very reliable tech as far as the rocket industry goes which is its own feat (even in modern times you still see rockets exploding on launch).
I'd have to imagine the Boring Company has hired some equally impressive engineers for mechanical engineering and understanding the science of tunneling...
I wonder if the secret is Musk not creating a huge layer of bureaucracy above engineering on top of a decent amount of funding, so they can really accomplish things.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
"The reason for the discrepancy is not yet clear." Uhmmm..... Electric motors display maximum torque at stall
Um... Not always.... In fact, often the maximum torque is defiantly NOT at motor stall for many common electric motor designs. Synchronous induction motors have zero torque at stall and standard induction AC motors often need help to get started by temporally adjusting the current phase of some windings to kick them forward.
DC motors tend to be highest current draw at stall and many have high torque when running slow. For Tesla's drive motors, I'm guessing the stalled torque is pretty high by design but they are not really DC driven, but are really AC motors driven by variable frequency and phases. With these motors you are able to adjust the torque in/out independently of RPM by varying the frequency and phase of the various windings.
I'm going to bet that the discrepancy really has more to do with the motor and drive electronics limits of both voltage and current and the power dissipation of the system. You will lose system efficiency at high currents because I^2 x R losses when the motor is turning slow.
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
Statler and Waldorf have moved from their previous job of reviewing live shows https://www.youtube.com/watch?... to reviewing cars at Munro & Associates . .When reviewing the new Tesla Model 3 they "still cannot find the gas cap after 3 days" and hooking two jumper cables to 12V to open a trunk "more complicated than programming my VCR , I never figured that one out either".
Both found that the BMW I3 the "most advance ever" with a electric range of 114 Miles and a 2 cycle generator option for extra range that gives off enough smoke "so you know it is working"
You clearly haven't been hanging out on the Model 3 Owners Club. It's amazing the disconnect between how certain individuals seems to want to portray it, and how non-selection-biased random owners describe their vehicles. Or, for that matter, photograph them. I watch person after person get their invite, pick up their car, and then rave at how amazing it is... then I check out the latest article to show up about the Model 3 on Google News where they act like everyone's car is held together by gaffer tape and they're furious.
To put it another way: "I just picked up my new (insert-topic-of-interest) and it was perfect!" doesn't go viral in the same way that "I just picked up my new (insert-topic-of-interest) and there was something wrong with it!". Seriously, for example, the rash of coverage over the person who had a dead 12V battery. Literally the only dead 12V battery that's ever been reported in a Model 3, and there were dozens of articles written about it - despite the fact that Tesla sent a guy to his house to take care of his battery for him.
Or more directly: check out some of the teardown videos linked in TFA. Does any of that look like poor build quality to you? One thing that's neat is you'll notice blue markings on a number of the bolts; that's common in the aerospace industry, but rarely in the automotive industry. Those are witness marks. They're used to double check that bolts were tightened to the proper tightness.
That's not to say that there haven't been some issues. Things that actually have been problems, at least over certain points in time:
* There used to be frequently a small sag in the hood, going a several millimeters out of alignment with the sides at its middle. It's been fixed in recent vehicles.
* While handling has gotten extensive praise, some people who don't like a stiff "sports suspension" feel have been complaining about that. Tesla is reportedly working to soften the suspension some.
* Noise, while quiet by ICE standards, is relatively high by EV standards. Namely, road noise (connected to the aforementioned stiff suspension) and wind noise (worse than the S). But both have been reducing with recent VINs.
* There's some issues that relate to preference. Some people don't like the Aston Martin-style door handles, while others aren't bothered by them. Some people think the door and frunk hood needs to be shut too hard, while others prefer the solid feel. Etc. So whether they're "defects" depends on your personal preference.
There are some GUI issues as well, but they decrease with each over-the-air update, as well as getting new features. At the top of the most-requested features list that hasn't been implemented yet is moving cruise control speed from the GUI to the right steering wheel control (akin to volume control and station selection are on the left steering wheel control). There have also been a couple issues related to it not remembering various types of infotainment / preference settings between drives; most (but not all) of these issues have since been patched.
Probably a couple other things I'm forgetting.
Point of interest. Offering to shoot us might not work so well as an incentive as you might imagine.
Completely different powertrain. The AC induction motor couldn't handle max power for more than a couple minutes because the rotor would overheat from induction currents. There's no induction currents in a PMSRM. Heating is in the stator, which is trivially cooled.
Meh, even Tesla's current induction motor fleet does that sort of stuff just fine. Watch Björn Nýland's videos, he tows huge things through mountains all the time.
Your post is well appreciated (I don't know why you were marked down to -1, that's unfair), but it's premised on obsolete technology. Motor technology is advancing fast, and Tesla has invested a huge amount of money into it.
Point of interest. Offering to shoot us might not work so well as an incentive as you might imagine.
[...] but what about towing a two-axle mobile stable with two horses in it, steep uphill?
I don't own any horses.
You're right--electric cars in general may suck towing heavy trailers up steep hills. So if that's something you're doing a lot of, I would not recommend buying a Tesla.
Now the other 99% of us who don't tow heavy trailers up steep hills, we'll be quite happy. And you'll be quite happy with your ICE car that does that towing with no problem.
>>> meaningless until Tesla cars can lap the world standard Nurburgring Circuit at speed.
Can't remember the last time I did that.
>>> what about towing a two-axle mobile stable with two horses in it, steep uphill?
I'm pretty sure that the bog-standard BMW 3-series wouldn't be particularly happy about that task either. I'm not quite sure where you'd mount the 5th-wheel hitch, either. That's why there are heavy-duty pickup trucks in the world. I guess we can revisit your challenge once the Tesla Semi is hauling 80,000 pounds around the US.
Is there a reason that you believe a mid-sized sedan should both lap the Nurburgring at speed, and pull a horse trailer?
And the worms ate into his brain.