Exoskelton fake news?

[Ehninger1212]

I dont think some people realize just how much aluminum we have on modern trucks... This mega casting aluminum piece for the rear will be WAY stronger than some flimsy frame rails. They get damaged very easy off road as is.. usually you have to beef them up in the aftermarket.

Those castings mixed in with the SS exoskeleton! Gonna be CRAZY strong. I cant wait.

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[VolklKatana]

Why does the casting 'doubt' exoskeleton?

A bridge still has a deck. We still need something for the motor and suspension to mount to. Even a crab has internal structures that its gills and ligaments mount to!

That's what the casting is. That doesn't change the exoskeleton.

None of their other vehicles are body-on-frame. And they have castings.

-Crissa

This totally hits the nail on the head.

Did we actually think the would just bolt to suspension and motors directly to that flat piece of exoskeleton steel? No! The torque and force that those motors produce would be more an enough to rip some bolts through that metal over time. The casting will be attached to the rear half or the exoskeleton to fortify the rear motors and bed area.

I would take anything from the InsideEVs website with a grain of salt...remember back to before the release party some of the wild articles they were throwing out just for clicks? Not really the most trustworthy source

 

[VI Tesla]

Why does the casting 'doubt' exoskeleton?

A bridge still has a deck. We still need something for the motor and suspension to mount to. Even a crab has internal structures that its gills and ligaments mount to!

That's what the casting is. That doesn't change the exoskeleton.

None of their other vehicles are body-on-frame. And they have castings.

-Crissa

Thanks Crissa, was waiting for you to chime in
Funny because I was thinking of the crab/bug example as well.

 

[Sonnus]

Did we actually think the would just bolt to suspension and motors directly to that flat piece of exoskeleton steel? No!

It is very reasonable to think the drivetrain and suspension components would directly bolt to the exoskeleton. Cars have been built like this since the 1960s. I restored an old Camaro that was built this way. And don’t tell me, “of course Tesla wouldn’t use 60 year old technology!”. Formula 1 cars do the exact same thing, bolt suspension and drivetrain to the monocoque (exoskeleton) body.

The Cybertruck reveal clearly showed a traditionally cast internal frame with all the compound curves that were subsequently said to be impossible or impractical. I think your expectations exceeded the reality.

These smooth internal parts are not cast components in this picture. These are stamped stainless(?) steel, like every other car made on the planet. Open the door on any car you currently own and look at the B pillar, it is identical. Tesla would just need to use a lighter gauge 30x SS to be able to stamp these parts, very simple.

Also, essentially all truck beds are sheet metal (few are composites). They strengthen them by adding welded stamped cross-members.

I am not saying that Tesla’s engineering is wrong with the cast aluminum subframe, I just think it is a cost saving measure. I’m guessing that people that abuse their work trucks like me will likely see issues in the future.

 

[BillyGee]

Why does the casting 'doubt' exoskeleton?

A bridge still has a deck. We still need something for the motor and suspension to mount to. Even a crab has internal structures that its gills and ligaments mount to!

That's what the casting is. That doesn't change the exoskeleton.

None of their other vehicles are body-on-frame. And they have castings.

-Crissa

Beat me to it. This article seems like fudster nonsense meant to deride tesla based off of things you should know if you're ever built a lego set.

A substructure with an exoskeleton is still a unibody. Not sure why that's hard to understand.

I’m guessing that people that abuse their work trucks like me will likely see issues in the future.

What issues do you foresee? If the design of the CT is anything like tesla's other vehicles it's going to be comically tough to the point of breaking safety testing equipment (like the model S did). What's more, those vehicles are full aluminum.

I assume the CT is going to be tougher than my F350 is, but I've come to feel like that's kind of a low bar for a vehicle. What exactly are you planning to do to your CT that makes you so worried?

 

[Crissa]

It is very reasonable to think the drivetrain and suspension components would directly bolt to the exoskeleton.

What car is that?

-Crissa

 

[CyberOwl]

Once, long ago, Elon said the Cybertruck would be made with Titanium, lots and lots of Titanium. Is that an option for casting?

 

[Sonnus]

What issues do you foresee? If the design of the CT is anything like tesla's other vehicles it's going to be comically tough to the point of breaking safety testing equipment (like the model S did). What's more, those vehicles are full aluminum.

I think if the cast aluminum components are a major structural portion of the frame then this may be a point of failure. This is based on my experiences in the past with repairing cast aluminum.



The other problem is you are not going to be able to weld the cast aluminum to the stainless exoskeleton. It will need to be bolted or bonded (glued) together. This is not ideal. Having a completely stainless exoskeleton welded to mounting rails for the drivetrain, etc would be a more homogenous way to do it. My guess is that the aluminum subframe was chosen purely on the financial benefits (cost savings).

I assume the CT is going to be tougher than my F350 is, but I've come to feel like that's kind of a low bar for a vehicle.

I do not have blind confidence in Tesla’s cars. I have a 2018 Model 3 that has just over 30k miles and my car has noticeable creaks and rattles. My Tesla replaced a 2009 X5 diesel with >130k miles that had none of these issues. Do I regret getting the Tesla? Definitely not, all of the positives easily outweigh the negatives. My point is that Tesla’s cars and engineering are not perfect.

What exactly are you planning to do to your CT that makes you so worried?

I haul 12k+ dump trailers and equipment all over job sites. Regularly, I am hauling heavy loads over non-graded hillside dirt lots that constantly tweak the frame back and forth. This gets repeated over and over all day long, non-stop. I also have a 10k toy hauler that gets pulled deep into the National forests over very rough dirt roads.



I have no doubt that the Cybertruck will be able to handle hauling loads off-road from time to time. I am just not sure a cast aluminum frame is ideal to tolerate this repetitively day in and day out.



I will certainly find out. like I’ve stated before, I have no intention on canceling my Cybertruck order.

What car is that?

Essentially all cars are built this way, including all of Tesla’s cars. As BillyGee stated, the Cybertruck’s exoskeleton design is basically just a unibody frame like every other car. It has the exact same components (aprons, A/B/C pillars, quarter panels, floor pans and mounting rails) that every other modern car has.



The groundbreaking part of the Cybertruck’s design is that the unibody frame does double duty at the body panels. This is a genius cost saving way to make a vehicle.

 

[Crissa]

I think if the cast aluminum components are a major structural portion of the frame then this may be a point of failure. This is based on my experiences in the past with repairing cast aluminum.

Cast aluminum can come in lots of different strengths.

But if this part is broken, well, the back of the truck has been broken. There's unlikely any repair at that point. Crumple bars can be replaced, but if the damage is further... What would be left of the vehicle?

The other problem is you are not going to be able to weld the cast aluminum to the stainless exoskeleton. It will need to be bolted or bonded (glued) together. This is not ideal.

Your statement is decades out of date for fastening and bonding technology. Sometimes bolts are better than welds, but composites are stronger than welded steel now.

I do not have blind confidence in Tesla’s cars. I have a 2018 Model 3 that...

...doesn't have the mega castings in it. It has the least aluminum of the Model 3s built. No one is asking you to have blind faith.

I am hauling heavy loads over non-graded hillside dirt lots that constantly tweak the frame back and forth.

...That's because the frame is a narrow ladder. That's what the exoskeleton is designed to prevent.

Essentially all cars are built this way...

No cars are built this way:

It is very reasonable to think the drivetrain and suspension components would directly bolt to the exoskeleton.

They're instead built like they're proposing for the Cybertruck: A unibody with a lower assembly to hold the motors and suspension. In fact, an aluminum one.

There has to be something to mount the motors to. This isn't a go-cart, you can't mount it to the outer body.

-Crissa

 

[ScoobyDoo]

You're all way off.... it's gonna be cast Unobtanium mined from passing asteroids. The whole Starship Mars thing was just a cover up. It's for mining asteroids. That's why Elon was so upset that they couldn't test the SN9 yesterday. He needs that thing hauling Unobtanium asap to keep the Cybertruck on schedule. Silly ya'll didn't realize that. ?

And the HPDC machine isn't on IDRA's website because it's their special Plaid model. You have to already own the OL 5500 CS HPDC model to be allowed to buy the Plaid model.

 

[Sonnus]

A titanium Cybertruck would be epic. I would honestly be willing to pay >$100k for a titanium Cybertruck but that unfortunately won’t happen. Unless Tesla designed a Mars-spec Cybertruck. Then titanium starts to make more sense.

No cars are built this way:

What on God’s earth are you talking about? Of course all cars are designed and built with unibody frames. Are me and BillyGee the only two people in this thread that realize the Cybertruck is a unibody frame design?

Your statement is decades out of date for fastening and bonding technology. Sometimes bolts are better than welds, but composites are stronger than welded steel now.

I’ll have to challenge you on this one, what exactly makes my statement outdated? Welding is always stronger than bolts or bonding in regards to metal. When the SpaceX Starship was first designed it was made of carbon fiber (one of the best composites available). But then SpaceX scrapped millions of dollars worth of engineering and research to abandoned the carbon fiber and go with welded stainless steel. What exactly are you talking about? I have to imagine you are comparing a few random spot welds to a completely bonded structure. The bonding is obviously stronger in this case. With the spot welding you are only fixing a few small points together whereas the bonding occurs along the entire seam. Also, spot welding is the absolute worst kind of welding you can do.

Cast aluminum can come in lots of different strengths.

The fundamental material properties can not be changed. You can expand their envelopes with alloys but not by much. Anyone that has worked with cast or extruded aluminum knows these limitations very well. Let’s find a metallurgist to see what they have to say on the subject.

...doesn't have the mega castings in it. It has the least aluminum of the Model 3s built. No one is asking you to have blind faith.

Never said my car has a megacasting. My comment was simply in regards to Tesla’s engineering and build quality. I thought I made that pretty clear?

 

[Crissa]

I'm done talking to someone who doesn't own up to their errors.

No cars are built this way:

It is very reasonable to think the drivetrain and suspension components would directly bolt to the exoskeleton.

I make enough of my own, but straight up lying about what I quoted is too much.

-Crissa

 

[Sonnus]

I'm done talking to someone who doesn't own up to their errors.



I make enough of my own, but straight up lying about what I quoted is too much.

-Crissa

Yikes, I never altered your quotes. Everything is here in black and white. I certainly did not mean to offend you.

I think it’s most likely we are interpreting the “exoskeleton” in two completely different ways. It seems you had envisioned all outer panels with nothing on the inside. I never interpreted it this way. When Tesla said the Cybertruck was an exoskeleton I automatically assumed this included all of the components of a traditional unibody frame with the rails and floor pans included. In fact, if you look at Tesla’s exoskeleton in the above posts you’ll see that the A/B/C pillars are clearly there like every other unibody that exists today.

 

[Crissa]

I think it’s most likely we are interpreting the “exoskeleton” in two completely different ways. It seems you had envisioned all outer panels with nothing on the inside.

Dude.

Misrepresenting what I have posted is uncool.

...We still need something for the motor and suspension to mount to. Even a crab has internal structures that its gills and ligaments mount to!

That's what the casting is. That doesn't change the exoskeleton.

You on the other hand have posted

...that the stainless monocoque frame design...

It is very reasonable to think the drivetrain and suspension components would directly bolt to the exoskeleton. Cars have been built like this since the 1960s.

(No cars have been built like that)

A uni-body (or unit-body aka 'moves as one') is not the same as 'exoskeleton'. You're swapping terms around when you speak but then pretend I swapped around when I did not.

-Crissa

 

[Sonnus]

Dude.

Misrepresenting what I have posted is uncool.

You on the other hand have posted


(No cars have been built like that)

A uni-body (or unit-body aka 'moves as one') is not the same as 'exoskeleton'. You're swapping terms around when you speak but then pretend I swapped around when I did not.

-Crissa

My friend, I'm simply trying to find common ground for us to understand each other on. I am trying to understand this conversation from your perspective and I am also trying to describe things from my perspective.

I think of "exoskeleton" as a clever marketing term that Tesla came up with to describe their unibody frame construction. All manufacturers do this and Tesla is no different.