Model 3 teardown program

[David Green]

He is assuming no FEA because the parts appear to be heavy. But I think that is likely due to planned additional loads and capabilities for the dual motor and performance versions. Keeping the same parts across the model variants saves costs and eases assembly.

Tesla uses Dassault Systems 3DX PLM system and applications for engineering. Which includes advanced CAD, FEA, CAE, manufacturing simulation packages.

I am not familiar with the specific software, but with any FEA system you need experienced designers and operators to get the best results, you also have to have very detailed data on the actual parts loading in all axis, temp, etc... to get the most optimized results, what Munro found on Model 3 was defiantly rookie level work as Munro stated in the video (this makes me think Tesla might have done the production engineering in house on Model 3 which they did not do on S and X) . He was especially critical of the rear of the car which is where I have seen the most problems on the Model 3's I have seen... Actually front hood and back trunk area. By chance Bjorn Nyland just posted a video today where he crawls inside the trunk of the Model 3 and you can clearly see some of the pieces Munro is talking about. The other part Munro was puzzled by was the upper A arms that were stamped steel, and then injection molded. This is not at all optimal, and looking at the part I think they stamped the parts, and then discovered a problem in test (weakness or vibration), so rather then throw the parts away they may have tried to strengthened them with the injection molding? I cannot think of any other reason to design a part that way, and especially make them so heavy.

 

[Cypress]

That is not always true, especially if you are talking about a cast or forged-machined part. In a stamped part, what you are saying might be true. When you are trying to get the parts completely optimized, you are even looking for a gram here and a gram there. This the the way the big automakers do cars these days.

I have 20+ years of structural engineering background and CAE development, working in a field where weight optimization is much more critical than in automotive. Engineering and design is always a trade. Low cost, low weight, easy/fast to build (pick 2).

Let’s just save some time and assume I’m always right. /jk.

 

[Cypress]

I am not familiar with the specific software, but with any FEA system you need experienced designers and operators to get the best results, you also have to have very detailed data on the actual parts loading in all axis, temp, etc... to get the most optimized results, what Munro found on Model 3 was defiantly rookie level work as Munro stated in the video (this makes me think Tesla might have done the production engineering in house on Model 3 which they did not do on S and X) . He was especially critical of the rear of the car which is where I have seen the most problems on the Model 3's I have seen... Actually front hood and back trunk area. By chance Bjorn Nyland just posted a video today where he crawls inside the trunk of the Model 3 and you can clearly see some of the pieces Munro is talking about. The other part Munro was puzzled by was the upper A arms that were stamped steel, and then injection molded. This is not at all optimal, and looking at the part I think they stamped the parts, and then discovered a problem in test (weakness or vibration), so rather then throw the parts away they may have tried to strengthened them with the injection molding? I cannot think of any other reason to design a part that way, and especially make them so heavy.

If interested, you can sign up for a free seminar on CATIA functional generative design
https://www.3ds.com/events/single-eseminar/catia-function-driven-generative-design-webinar/

Or there are some YouTube videos.

But it basically allows for topology optimization as you are describing FEA (but FEA is much broader than that and has existed for much longer than topology optimization) but also allows to remaster the shapes to be more traditionally manufactured via forging/casting or machining.

 

[David Green]

haha! OK, you win! I am just a dirty old construction worker... ~ Actually I worked a fair amount on hydroplanes (as a hobby), and as I said before my neighbor is VP of Altair Engineering (I built their house), so that is my only limited experience. I do have a fair amount of friends around Detroit from the days when Progressive Tool helped us on the race boats. You mentioned CATIA, do you work in aerospace?

 

[Pushmi-Pullyu]

I don't seem to be able to upload a picture to my "Album" section from my Profile page, so I guess I'll have to do it by posting the photos here.

These are a couple of screen shots where, in the Munro video, they ridiculously claimed you could "barely get a fingernail in" on one side of the trunk panel gap, and "almost get your thumb in" on the other side. I'm posting them merely to show how ridiculously they exaggerated the fit-and-finish issues on the Model 3.

 

[Domenick]

It looks like there could be some variation in the gaps there, but it's hard to tell from just looking at the video. It would have been better had they just showed the measurements with a tool instead of making a claim which sounds a little exaggerated.

 

[Pushmi-Pullyu]

It would have been better had they just showed the measurements with a tool instead of making a claim which sounds a little exaggerated.

Maybe it's just me, but it looks like it's exaggerated a lot, not just "a little".

To be fair, these photos are a lot smaller than the actual car is, so variations may be easier to see if you're standing right next to the car looking closely. The thing is, I don't think most people examine the panel gaps on cars that closely. Not even when they buy them. So who cares? Seems to me this is nit-picking to a ridiculous degree. It appears to be a case of Munro going out of his way to look for unimportant things to complain about, when the important stuff is just fine.

Just my opinion, of course.
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[David Green]

Maybe it's just me, but it looks like it's exaggerated a lot, not just "a little".

To be fair, these photos are a lot smaller than the actual car is, so variations may be easier to see if you're standing right next to the car looking closely. The thing is, I don't think most people examine the panel gaps on cars that closely. Not even when they buy them. So who cares? Seems to me this is nit-picking to a ridiculous degree. It appears to be a case of Munro going out of his way to look for unimportant things to complain about, when the important stuff is just fine.

Just my opinion, of course.
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You are absolutely right it doesn't matter a bit to how the car moves you from point A to point B. Its all about perception and perceived quality. My wife likes Hermes purses, and they are crazy expensive, some of hers cost more then a Nissan Leaf (not kidding) but when I look at them the design is simple, but the quality is fantastic. Each stitch is perfectly done. Does it hold her wallet and phone any better then a dollar store purse? nope! But she likes it, and appreciates that attention to detail. When I bought our companies last dump truck, I went to pick it up myself, and found a few scratches in the paint and an imperfection on the aluminum fuel tank. I had them fix it, and on the fuel tank they gave me a rebate because it was not fixable without a replacement. Did this matter the next day when we drove the truck on the construction site in the mud... No, of course not, but I paid a price for a new product and it should be delivered as designed and expected. I guess if you buy a quality product you should expect it to have mechanical quality and also cosmetic quality. If I bought a Kia in the 90's at 50% below typical car price I might lower my expectations, but when it is a premium product I expect nothing less then the best. In the case of the Tesla Model 3, its the corner cutting in the manufacturing process that chaffs me. My buddy who works for Space X has a very flawed car, now I am not even sure if he paid full price as he is not allowed to talk about that, or let me take pictures, but the car is far from perfect. It does run and drive every day, and he drives it to work here in Redmond, so I guess it is functional. Typically when our group of friends talk about the car he just changes the subject. His was a Oct-Nov 2017 built car, those were rough ~