No Exoskeleton

[Deleted member 17810]

The knight suit of armor isn't an exoskeleton because...it's a suit.

Sponsored

 

[cvalue13]

So you think it was built as a body on frame with stainless steel panels?

I’m saying the on-stage prototype was absolutely not built as a 3mm stainless steel monolith with no internal structures

That prototype has seams in the metal (eg along the waistline of the sail pillar) that show they were unable and not intending the prototype to be more than a prototype

That prototype was built with large segments made of relatively flimsy, thin, metal. here’s a photo, from a member here, of that prototype’s quarterpanel metal (right) compared to 3mm (left)

so, yes, as a prototype it was probably built around some sort of one-off rolling chassis with the externals hung upon them

 

[Cybergirl]

The reveal prototype still exists, and will continue to exist for posterity. We'll one day find out who's right. I say it was a structural exoskeleton.

 

[Jhodgesatmb]

based on what?

it was a prototype, in most places using ~less than 1mm sheet metal to approximate the look

they didn’t have the breaks etc needed to form the 3mm of the entire CT into “an exoskeleton in the true sense of the word”

Unless you or someone cut the prototype you don’t know either so why bother with this kind of statement? I suspect that the entire prototype was indeed 3 mm stainless but that is based on what everyone at Tesla said and not on any ramblings of my own.

 

[Jhodgesatmb]

The knight suit of armor isn't an exoskeleton because...it's a suit.

Even an exoskeleton suit such as those in The Matrix, Avatar, or in real life are providing extra weight or load redirecting capabilities to an otherwise fairly flimsy endoskeleton creature. I am not arguing against the use or misuse of the term; only saying that it is used quite liberally across industries. It is clear that Elon’s use of the term has brought out the worst form of trolling but I believe his intention was always to mean that the skin of the Cybertruck will be extremely durable compared to other trucks and I expect that to remain the case no matter what anyone calls it.

 

[cvalue13]

Unless you or someone cut the prototype you don’t know either so why bother with this kind of statement? I suspect that the entire prototype was indeed 3 mm stainless but that is based on what everyone at Tesla said and not on any ramblings of my own.

Tesla never said that - it said the truck it was going to build would be 3mm

And if we’re going to exclude conjectures, then your original post is also out the window

strange discussion

 

[cvalue13]

The reveal prototype still exists, and will continue to exist for posterity. We'll one day find out who's right. I say it was a structural exoskeleton.

then, why don’t you go visit it? It’s on display. And ask folks around here who have gone to see it. It’s unanimously with folks would describe in the collector auto world as a “12 footer.” I let looks pretty good from 12 feet or more away. Get any closer and you can tell real fast it’s a prototype.

 

[Cybergirl]

Get any closer and you can tell real fast it’s a prototype.

Who said it wasn't a prototype?

 

[GlockandRoll]

I'm not sure I agree with this, as it's really just semantics. You can clearly see that the the body isn't made of panels, and is part of the structural integrity of the vehicle. Crumple zones are mandated federaly, if I am not mistaken, so seeing that doesnt mean that the body isn't also structural.

 

[JBee]

I have a suit of "amour" on right now, and nothing you say can hurt me, because I love myself a more! ? ? ?

 

[Aces-Truck]

From my point of view, what's amazing about the Structural Design of CT is that it's NOT Bed on Frame. Look at a bridge over water. it's a truss, that leverages the tall size of the structure to handle more bending stress with less materials.

Look at a conventional Pickup, right where the bed should touch the Cab. There's a Gap there. And it needs to be there. Why? because the Frame that both the Cab and the Bed sit on will flex under load. The two would hit under the right loading. There is all that movement due to Deflection of the frame as you change the load.

If you look at the height of the Ladder Frame on a conventional pickup, it's tiny compared to the height of the Cab. Strength, and Stiffness, increase by the Square of the Height of the Beam But if you increase the Height of the Ladder Frame, you get the cab and bed so high it causes other problems.

With the CT (and similarly a Honda Ridgeline), the cab and Bed are part of the Truss system that handles the Bending Loads. The Beam height is same as the Cab height. Much more rigid. Requires less materials to handle the same Payload. I believe that was the point all along with the CT design. OP is correct that it's not a true Exoskeleton. But really, that's not so important to handling large Payloads.

 

[LDRHAWKE]

As I said to fullygrounded in July 31…

“

FullyGrounded said:
We do understand that the frame is like the backbone of the vehicle, right? And, now, we've taken and moved that from the protected, to that which protects and will take the brunt of damage.

Now, they will also crease it to allow for it to crumple. You've just made my back weaker. And, off road, that is so critical. Frames will flex if they can. Well, will it crumple? So many questions that Elon and physics need to answer. I'm, right now, not sold on an exoskeleton. I'm sure there are those that will beat on this exoskeleton body, and then we will see what the result is.

I think that was the original idea to have the stainless body and simply attach things to it, but I believe that might have all changed with the large casting front and rear and battery structure in between that has evolved. It looks like the truck body can simply be fit on top and attached to the three piece structure, with the evolution of the mega castings.”

 

[cvalue13]

Look at a bridge over water. it's a truss, that leverages the tall size of the structure to handle more bending stress with less materials.

serious question:

other than being triangle-shaped at a macro level, in what ways is the now-known functional structure like a truss?

 

[Aces-Truck]

serious question:

other than being triangle-shaped at a macro level, in what ways is the now-known functional structure like a truss?

You are correct that a Bridge Truss involves typically dozens of links. CT is like a large Triangle (3-Piece Truss). But the reason Bridges have so many links is that those in Compression can buckle if they are too slender compared to their length. So the extra links prevent that. CT is quite shorter of a span. and there are other elements that would help prevent buckling.

The big deal is that the Ladder frame on a Truck is like maybe 8"-14" tall (somebody with a tape measure check this please). The CT Cab height creates a Triangle that's say 40"-50" tall. If my assumptions and math is right, the same amount of metal in the top and bottom of CT, compared to that in a Conventional Truck would, provide 12 to 25 times as much capacity for Beam stress caused by payload acting between the two axles.

The reason a Triangle works so good here, is that the Bending loads are greatest mid-way between the axles. And drops to considerably less over the axles.

 

[cvalue13]

If my assumptions and math is right, the same amount of metal in the top and bottom of CT, compared to that in a Conventional Truck would, provide 12 to 25 times as much capacity for Beam stress caused by payload acting between the two axles.

still serious:

I believe as far as we know, the cab frame is steel (though not 3mm SS), and certain the castings are aluminum. As I understand it, those materials don’t play/weld together well.

These joints occur in the middle thirds of the vehicle, fore / aft of the SS cab.

What’s described above so far, is roughly the same construction as the Model Y.

The Model Y most definitely couldn’t tolerate the sort of payload / towing specs attributed to the CT.

Those loads occur essentially at the rear hitch. In a traditional boxed frame truck, those stresses would cause failure above or just foreward of the rear wheel - the suspension acting essentially as a fulcrum, with the payload/tow weight behind the rear wheel, and on the other side the weight of the front of the truck ahead of the rear wheel.

With the Model Y, where would that point of failure be? Would the suspension itself give first? And if not, where would the Model Y casting/cab separation occur? I assume at/near the joint between cab and rear casting.

Now if the subframe of the Model Y can’t tolerate that sort of CT-level spec of payload/towing, what is it about the CT frame (cab + castings) that allows it to?

Sponsored