Munro: Cybertrucks exoskeleton & castings deep dive w/ Tesla's Head of Vehicle Engineering

[Administrator]

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[cvalue13]

Interesting stuff here

mostly for @JBee:

(1) they call the BIB part of the exoskeleton

(2) he explicitly says all the load path goes through the castings (and so BIB)


so, in Tesla’s view, it’s an “exoskeleton” to the extent the castings and BIB are part of the “exoskeleton”, and specifically the operational load-bearing part of the “exoskeleton”

which pretty much puts to bed the notion the exterior stainless steel is material to the load bearing structure of the stainless steel-only portion of the structure



not that you-know-who’s won’t be along any minute to keep arguing otherwise…

 

[JBee]

(FYI this is an extract from the full Monroe deep dive video, specifically about the frame.)

It's interesting that they don't mention the SS skin at all in the discussion of the exoskeleton, and directly label the cabin frame and casts as the "exoskeleton".

This means the Tesla Model Y also has a "exoskeleton" by their definition because it shares those parts. I haven't seen anyone disagree calling a MY a unibody...yet.

The point is that most of these parts are common elsewhere, China makes cars with casts and unibodies already... so this seems more of a rebranding to differentiate rather than there being something that we have never seen before in a vehicle.

I don't really care about what they "brand" it, so long its clear its branding, but I am interested in if, how and where the SS skin takes operational load in the design. Hopefully we'll see some more details on that soon.

 

[cvalue13]

This means the Tesla Model Y also has a "exoskeleton" by their definition because it shares those parts. I haven't seen anyone disagree calling a MY a unibody...yet.

The point is that most of these parts are common elsewhere, China makes cars with casts and unibodies already... so this seems more of a rebranding to differentiate rather than there being something that we have never seen before in a vehicle.

I think the fairer interpretation is that the exoskeleton is composed of:

• castings + BIB (operational load bearing)

• glass + pack (operational load bearing + ingress)

• stainless outers (ingress)

In which case, it’s the last bullet that makes the CT unique compared to MY etc., including in how the stainless reduces or obviates the need for some additional ingress features in the BIB (eg deletion of the standard sort of anti-ingress bars in the doors).


which difference isn’t nothing, and is in fact arguably a step-change in the way a MY is a post-molt soft-shell crab (not *quite* an exoskeleton, given absence of material exterior ingress protection) whereas an CT is a Christmas Island Red between molts**

Stainless outers sure didn’t seem to save material weight, and not materially adding to operational load-bearing, but …




**before the told-you-sos rush in: no one serious ever disagreed that animals with exoskeletons had inner structures, the serious disagreement was in the added assertions that the SS was operationally load-bearing, and material to more than the obvious Joe Rogan-stopping ingress functionality

 

[Mr.Dee]

@cvalue13 @JBee
Oh hey guys. Fancy seeing you here.

I'm just here to get notifications from the structural exoskeleton crowd.

 

[Coolbreeze704]

I think the fairer interpretation is that the exoskeleton is composed of:

• castings + BIB (operational load bearing)

• glass + pack (operational load bearing + ingress)

• stainless outers (ingress)

In which case, it’s the last bullet that makes the CT unique compared to MY etc., including in how the stainless reduces or obviates the need for some additional ingress features in the BIB (eg deletion of the standard sort of anti-ingress bars in the doors).


which difference isn’t nothing, and is in fact arguably a step-change in the way a MY is a post-molt soft-shell crab (not *quite* an exoskeleton, given absence of material exterior ingress protection) whereas an CT is a Christmas Island Red between molts**

Stainless outers sure didn’t seem to save material weight, and not materially adding to operational load-bearing, but …




**before the told-you-sos rush in: no one serious ever disagreed that animals with exoskeletons had inner structures, the serious disagreement was in the added assertions that the SS was operationally load-bearing, and material to more than the obvious Joe Rogan-stopping ingress functionality

So when did they start teaching engineering in law school?

I know, you are a patent lawyer?

 

[Deleted member 17810]

Mmmm

Exo

 

[HaulingAss]

I don't really care about what they "brand" it, so long its clear its branding, but I am interested in if, how and where the SS skin takes operational load in the design. Hopefully we'll see some more details on that soon.

Why would you be interested in how and where the stainless skin takes operational load in the design when you are sure it doesn't take operational load? That was you claim when you first said it wasn't an exoskeleton due to some nonsense about loadpaths not being able to go through the skin. Now it's OK to call it an exoskeleton and you want to know how the operational loads are transferred through the skin. It's like I already told you, the other components of the exoskeleton flex (Lars commented on how much the casts flex) and the skin resists that flexing, spreading those loads to different parts of the castings and stampings.

It's been fun to watch your position morph over time, while pretending it hasn't morphed. Houdini would be proud of your contortions!

 

[SlegMD]

Oh damn

 

[cvalue13]

@cvalue13 @JBee
Oh hey guys. Fancy seeing you here.

I'm just here to get notifications from the structural exoskeleton crowd.

 

[cvalue13]

So when did they start teaching engineering in law school?

I know, you are a patent lawyer?

was almost a patent/IP lawyer, but…

 

[JBee]

Why would you be interested in how and where the stainless skin takes operational load in the design when you are sure it doesn't take operational load? That was you claim when you first said it wasn't an exoskeleton due to some nonsense about loadpaths not being able to go through the skin. Now it's OK to call it an exoskeleton and you want to know how the operational loads are transferred through the skin. It's like I already told you, the other components of the exoskeleton flex (Lars commented on how much the casts flex) and the skin resists that flexing, spreading those loads to different parts of the castings and stampings.

It's been fun to watch your position morph over time, while pretending it hasn't morphed. Houdini would be proud of your contortions!

When did you stop writing for the Washington Post and make CTOC your full time job?

If only you knew how to use the search function you could actually bring an counter argument. Nothing though, just more strawman.

FYI I was the one that told you about the bed torsional rigidity, not the other way round. So my interest hasn't changed one iota.

 

[cvalue13]

When did you stop writing for the Washington Post and make CTOC your full time job?

If only you knew how to use the search function you could actually bring an counter argument. Nothing though, just more strawman.

FYI I was the one that told you about the bed torsional rigidity, not the other way round. So my interest hasn't changed one iota.

I can’t see his comment (and he can’t see mine), and it’s not nice to talk behind someone’s back (though to be fair, in this analogy, med-convo *he* turned his back towards me):

please just keep asking him “source?”

 

[ziggy]

What's are the bumpers made of? My guess is its stamped high strength boron steel.

 

[HaulingAss]

When did you stop writing for the Washington Post and make CTOC your full time job?

If only you knew how to use the search function you could actually bring an counter argument. Nothing though, just more strawman.

Why would I waste my time searching through your old posts? I have nothing to prove to you, the record is already clear (and if you were honest with yourself, you could see how dramatically your position has morphed over time).

FYI I was the one that told you about the bed torsional rigidity, not the other way round. So my interest hasn't changed one iota.

Huh? I was the one schooling you on torsional rigidity from the beginning of your anti-exoskeleton silliness. You brought up the torsional rigidity of the bed long after I first schooled you on exactly how that works but you continue to push back as if you understood from the beginning.

Whatever, it's not worth my time now that the truth is out of the bag.

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