Tesla is facing issues with the bare metal construction of the Cybertruck, which Elon Musk warned was as tricky to do as making Lego bricks
“All parts for this vehicle, whether internal or from suppliers, need to be designed and built to sub 10 micron accuracy.”
LOL
Yeah ok.
Tell me you know nothing about manufacturing, without telling me you know nothing about manufacturing.
That one quote - assuming it is accurate - explains that Musk is even more of an idiot than everyone already knew he was. You don’t make things at those tight tolerances. A couple of dimensions on a part might be (for instance the bore on a press fit sleeve), but you’d almost never, ever hold an entire part to that tight of a tolerance.
In imperial units, 10 microns is .00039". A human hair is roughly .001 to .005" thick. So he is asking for a tolerance that is 3 to 10x smaller than the thickness of a human hair. To put the absurdity of Musk’s demand into perspective, most parts that go into a car are roughly an order of magnitude looser in tolerance with some dimensions being 2 orders of magnitude looser.
That difference might not sound like a lot, but holding something to +/-.0039 versus +/-.00039" could easily triple the price of an item or more. Easy. You use a tight tolerance only when you need to - that’s engineering 101. Some parts could easily be +/- .039" and not affect their performance on bit. Close tolerance engine parts might be held at what Musk is demanding, but never “ALL PARTS” would be held to that.
Not to mention the fact all the tolerances should have been determined before mass production began. You determine the dimensional requirements and develop the manufacturing process to deliver that.
There is absolutely no way they have the systems and tools in place to properly measure every part with sub 10-micron accuracy and precision either. To control those dimensions you need to go a whole additional order of magnitude out. I pity the fool that has to manage that control plan.
develop the manufacturing process to deliver that.
Exactly. I’m sure his engineers did the right thing and know what they are doing, and now the top executive steps his foot into the mix and will muck everything up.
I know exactly how the people that I have worked with in the past would have dealt with this - surrly engineers and quality managers who knew how to handle tough bosses. They would let the whole situation cool off for a day or two first. Then go tell him how much more expensive the truck would be if they tried to hold every dimension of every part to +/-.0004". Any sane CEO would quickly know he fucked up and issue some retract. If that still didn’t sway him because of his ego, we probably would stop even listening to him altogether. He has shown that he is utterly clues, so would he even know a part held to 10 microns versus one held to 100 or even 1000?? I’m guessing no. If he asked if these new parts were held to the tighter tolerance, we’d say yes and just go on about our day.
engineering 101
Mechanical engineering 101, us sparkies don’t get to learn that stuff until we get into the real world. Not bitter just disappointed in my uni.
Really? I’d have thought EEs would learn it in the context of something like circuit breakers using bimetallic strips or the effect of heat-cycling on soldered joints.
Seems like EEs are not taught a lot of practical things in school.
Yes. The field is way too broad and has been for decades. I have all this knowledge in my head that I never get to use (integration of 1 over the square root of arctan squared of x cubed), knowledge that would have bern useful in the 1970s (this is how to build a class C amplifier without soldering), and knowledge that would have been useful but wasnt taught (this is what FLA is).
The ideal would be to break it up into a few different degrees. Guys and gals working in Software Defined Radio shouldn’t have the same training as those planning powerlines.
I lost it on an intern a while back who wanted to drop out because “we aren’t learning anything practical”. Yeah I know kid, get your piece of paper and get to work.
I’ve heard almost the exact same thing from MEs as well. Both are sooo broad. I mead I get WHY they try to teach you anything and everything, but it does seem overwhelming and at the same time seems like you haven’t learned anything useful even when you really have. You simply don’t know if you’ll be working at a nuclear power plant dealing with thermodynamics or a car maker mostly dealing with design or as a project manager at some other company dealing with vibrations. There’s just no way to know. The path your work life leads is impossible to predict so they sort of have to teach you a little about everything.
Damn, I’m an EE and my university wasn’t too bad for having a good mix of theory vs practical. But I’m aware a lot of EE courses don’t do that.
BTW, are you Australian too?
Nope. I might have been to harsh a bit. My sub-field (controls and automation) is notorious for being poorly documented and most of the tech being very vendor specific. So you learn on the job.
I am sure plenty of the semiconductor EEs will disagree with me.
Ah yeh, fair enough. I didn’t do any controls and am. Now having to learn a bit for my job, but I like learning at work. It’s more fun than university.
When I was young I got a job at a manufacturing place that made all sorts of parts for sensitive equipment. Younger people, or people with steady hands would debur and smooth. We would have these huge magnifiers and friggin microscopes and be working with what looked like a really long tiny exacto knives that needed to be replaced every 5 minutes or a couple dozen uses to get that stuff to spec. You can spend 20 minutes on a piece, think it’s perfect and then QC would send it right back because they somehow found some tiny inconsistency or groove you didn’t or couldn’t notice.
There is no way you can expect that level of accuracy, unless your willing to pay for clean room level stuff. Even we weren’t always quite that accurate depending on the end use and they charged like almost $50 for something that looked quite like something you get a hardware store for 50 cents.
huge magnifiers
Probably an optical comparator.
Using a comparator for deburring breaks my QA addled mind.
I’ve told many (usually new) design engineers that they’re stupid for asking for 0.001" tolerance on parts when they only need 0.005 “or 0.010”. The difference between 0.010" and sub-10 micron is easily a factor of 100 in most parts, ESPECIALLY when you’re talking larger steel components like panels on a freaking car.
Unless you are talking about a press fit location or some kind of high precision alignment issue, almost nothing needs anything tighter than .001" and .005 or .010" is perfectly fine for most things. I work with a lot of weldments so if we’re within .030" we consider that good enough.
+/- .030 good enough for most skin panels on airplanes.
Gear teeth I believe need to be precision ground to less than a thou for best efficiency and life. But that’s not for most things.
I don’t see anywhere in the article where Musk says “tolerance”. He specifically says “accuracy” and goes on the talk about listing more decimal places instead of rounding. Any mention of tolerance is done by the author of the article. If certain dimensions are not naturally rounded to one, or even two decimals, there is no reason not to list it to three or more on modern drawings. GD&T can specify whatever tolerance is necessary without relying on a decimal-based block tolerance. I’d be interested in seeing the original email but it seems like there is a misunderstanding by the author given the context being discussed.
I default to three decimal places for all my basic dimensions on both in and mm drawings. One of the benefits of GD&T is that you can give provide additional dimensional accuracy, completely independent of the tolerance being specified.
That’s a really good point. If this is actually for the intervening calculations, that’d make a lot more sense.
The linguistics of metrology is not exactly a topic I’m particularly passionate about, but if yiu look at the technical definition of accuracy, it essentially is the same as a tolerance.
Accuracy: the degree to which the result of a measurement, calculation, or specification conforms to the correct value or a standard.
And when it comes to decimal places, you’d never display more than you really need. If a dimension is +/- .010" there is absolutely no reason to display it to 4 decimal places. That doesn’t win you anything. More importantly, I’m sure a company like Tesla doesn’t even use drawings at all. I’m sure they are paperless and send out their models for machining.
I think there is a very important distinction between accuracy and tolerance in engineering. +/- .010" is not a dimension, but a tolerance that can be applied to a dimension. However if your example was changed to a .010" dimension, I would agree with you as I stated in my last comment. There is no need to give any further accuracy to that dimension if you are just adding zeros to the end (unless you are using block tolerances that rely on a specific number of digits to correspond with a standard tolerance). Unfortunately, not everything is designed using the same units and you will inevitably end up with a part designed in mm that uses a bolt-on component using a hole span in inches (for example, a nice round 1-in span). If you want a +/-1 mm tolerance on that part, you wouldn’t want to round every dimension to the nearest mm because you may end up with a tolerance of 24-26 mm when you really wanted 24.4 to 26.4 mm. I like to provide true dimensional accuracy (to microns or .0001" if I’m not just adding zeros) and then apply a suitable tolerance independently, using GD&T.
Regarding paperless manufacturing, I agree that many components are made straight from the models these days and imported directly into a CNC machine. However, there should always be a drawing or a digital equivalent a drawing. This is the contract that specifies acceptable tolerances to the manufacturer, and it will be used during QA inspection to determine if an acceptable part has been delivered.
I think there is an important distinction between accuracy and precision in engineering. I’m having flashbacks of sitting in class when the professor was going over this stuff. I honestly always found it some of the most boring topics in the curriculum.
One of my physics profs had a story about this. He needed two resistors to be very similar in performance for a circuit he was making, so he asked for a couple of the super-high-quality ones.
His advisor said “fuck that, get the 1% bin, they’ll be bimodal at 1% above and below rating, sort em and find two that match to the degree you need”
That’s kind of analogous; do you need to try to hit a particular value (accuracy) or do you need things in a consistent relation to one another (precision)?
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Ethically I agree completely but this should only be done if you’re past your warranty (or don’t care about it).
I agree. And be ready for the insurance company to deny all claims related to the vehicle once they discover the “modification”.
can’t you just install a honeypot that simulates the stock firmware?
This just shows how dumb he is and that he doesn’t know shit. Unnecessary, unreasonable and unrealistic tolerances will not result in a better car!
That tells you of Elon’s brain surface roughness
Variations below 10 microns, like the car parts?
Like a bowling ball
Hahhaahhahaah
It’s just marketing. Elon wants dumb tesla bros to think their truck is built to that accuracy. No need for it to be reality.
As opposed to smart tesla bros?
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Why does Space Karen still have all his fanbois? Do they really think he’s some kind of software/technology/business genius, even after all that has come out about him?
He is talented, just not at engineering or science particularly.
His talents lie in obtaining government subsidies and trolling.
Yes, agreed.
Him and his companies have achieved some very impressive things, most notably Tesla being so far ahead of the pack with EV technology, and Space X with their reusable rockets.
Regardless of your opinion of him as a person, he has achieved some impressive things.
Which part(s) did he do, though?
Cybertruck, Cybertruck,
Engineers say “what the fuck”
Micron fits for auto steel?
Those are not a thing that’s real
So deal! Deal with it, Cybertruck.I read that in the Spiderman themesong’s rhythm lmao
This is what the refrance
Two things, not necessarily related.
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The cybertronk looks highly regarded when put together correctly. Imagine if it has the panel gaps of other cars TSLA makes.
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My tinfoil hat theory on why Elon is acting all right wing all of the sudden is to get those idiots to buy electric bare metal Pontiac Aztecs with “unbreakable” windows instead of F-150’s
100% everyone is making fun of teslas already, so imagine how the people feel who pre-ordered some garbage years ago. Now with their “leaked” email they can tell people how their future car will have toleraces that are on an qtomic level. These are also the prople who believed that teslas can fly in 3 years. Which was in 2016 i believe
My tinfoil hat theory on why Elon is acting all right wing all of the sudden is to get those idiots to buy electric bare metal Pontiac Aztecs with “unbreakable” windows instead of F-150’s
can he recoup $44 billion tho…? it’s a bold move.meme
wouldn’t it be nice to have some kind of logical explanation for his demented thrashings?
I don’t think he actually cares about the money he blew on Twitter. Money is a construct and that is even more true for rich people. If he cared about the money, he wouldn’t have tossed Twitter down the shitter.
I think he cares more about the impression he is making, whether it be good or bad. People are talking about Elon and that’s all that matters.
While I don’t know the cost to develop the cyber truck assuming it was 0 dollars to make the cost of the Twitter deal from cyber truck alone, it would take 88 thousand of them at elon getting 100% of the money from the sales. ( how he expects to sell an electric truck for 50k is beyond me)
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If Elon would have looked back, he would have seen that Delorean has already tried bare metal, and it’s nearly impossible to fix. Dent your truck? May as well paint it.
I mean, Elon obviously doesn’t care about repairability, but the first few fender benders will result in a pile of articles about how unfixable the body panels actually are.
But at least John DeLorean didn’t demand that the parts be accurate to within a few microns. Maybe he was too busy making cocaine deals to do it, but still…
I just realized how accurate the comparison probably is…
Although Musk is famously on Ketamine instead.
Sounds like a pr campaign
Hilarious considering the panel gaps in all his other cars, dude is fucking insane. Unattainable standards don’t breed better work they breed exasperation and apathy.
While holding this tight of a tolerance is standard for small sinple injection molded plastic part like Lego blocks (0.01mm tol. usually need some really good tooling though), it’s not really possible to hold this tight of a tolerance for large sheet metal construction such as the Cybertruck body (Standard tolerance should probably be in the milimeter range at most. )
So, guess the Cybertruck is never coming out.
Also, there is no way to actually measure this tight of a tolerance on large parts such as a car, since the standard methods for this tight of a tolerance measurement is… using a caliper, as using automated optical inspection for every dimension isn’t really feasible.
So, I guess they’ll probably just coddle Musk and make some fake drawings for his eyes only or something, which would only be more useless work for Tesla people.
Also, there is no way to actually measure this tight of a tolerance on large parts such as a car, since the standard methods for this tight of a tolerance measurement is… using a caliper, as using automated optical inspection for every dimension isn’t really feasible.
We definitely have lasers that can measure this tolereance.
Yeah, as I said, automated optical inspection isn’t feasible, it would be extremely cost prohibitive to set up laser fixtures for every dimension.
Guarantee he has no understanding of metalwork. It’s not tricky, it’s an exact science.
“Bad news guys… We’re gonna have to delay production for just TWO MORE YEARS because of these woke microns! The good news though, you can get re-premium upgraded waitlist VIP positioning with a renewal deposit of only $500”
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Oh fries please, he gets too easily distracted and just plays with the mash potatoes all dinner
So that’s how this PoS vehicle was conceived in the first place? That tracks.
This means something…
Every time I see it I can’t get past how hideous it looks. I just don’t get it…who’s the target demo for this thing? They’ve already been beaten to market by non-absurd looking trucks, how big could their market actually be?
