Exoskelton fake news?

[VI Tesla]

Pretty sure that by having floor costing front, back or middle does not preclude the exoskeleton design. The truck would require some sort of floor. If the entire truck was a casting it would still be an exoskeleton...

https://insideevs.com/news/482658/musks-remarks-cybertruck-doubts-exoskeleton/

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[Sonnus]

Tesla is worrying me with this, do they only expect these truck to be highway driven with the occasional light off-roading, like you might do with a new Range Rover? I hope the decision to go with an aluminum subframe doesn’t diminish the Cybertruck’s durability.

I ordered a Cybertruck to replace my 2012 2500HD Duramax Z71. My truck regularly hauls 10k trailers off-road that stressed the frame to the max.

I had complete confidence that the stainless monocoque frame design would be able to handle this. I do not think a cast aluminum subframe is going to be able to survive this same type of punishment for 10 years.

 

[VI Tesla]

Tesla is worrying me with this, do they only expect these truck to be highway driven with the occasional light off-roading, like you might do with a new Range Rover? I hope the decision to go with an aluminum subframe doesn’t diminish the Cybertruck’s durability.

I ordered a Cybertruck to replace my 2012 2500HD Duramax Z71. My truck regularly hauls 10k trailers off-road that stressed the frame to the max.

I had complete confidence that the stainless monocoque frame design would be able to handle this. I do not think a cast aluminum subframe is going to be able to survive this same type of punishment for 10 years.

Don't think that'll be the case.
They're designing a 8000 ton casting press specifically because they're designing the CT to be beat on and carry and haul heavy loads. At the end of the day these castings will be much more rigid/strong compared to tradition ladder frame design. Way stronger IMO!

 

[Sirfun]

Remember your Hot Wheels as a kid? There was the body and the bottom plate mounted together. This will be kinda like that. A casting isn't that structural. Not like a frame.

 

[Sonnus]

Remember your Hot Wheels as a kid? There was the body and the bottom plate mounted together. This will be kinda like that. A casting isn't that structural. Not like a frame.

I am not sure I want Tesla getting engineering inspiration from a toy.

All joking aside, I think this approach is fine for a car that is intended to drive on smooth roads. I just don’t like the idea of a cast aluminum frame on an off-road truck. A truck frame gets twisted, stressed and abused if you use it like I intend to. And, regardless of how well it is engineered and built, cast aluminum does not respond well to this.

 

[Dids]

No one said cast aluminum . It could be cast stainless steel. Also no one said cast frame. The frame of the CT is the external cold rolled 30x stainless steel. Elon said CT requires an 8 ton casting machine because its a bigger part.

 

[Sonnus]

I think it is very logical to assume that Tesla is intending to use aluminum. The 8,000 ton die casting press mentioned in regard to the Cybertruck would only be used for aluminum or some other low melting temp metal.

Investment casting is generally used for steel or stainless. Think of the old-fashioned foundries pouring molten steel into a sand-cast mold. A Gigapress is not be needed for this.

BTW, I don’t intend on canceling my Cybertruck order even though I would definitely prefer a completely stainless steel frame without major cast aluminum components. I just foresee cracked aluminum subframes being discussed on this forum 10 years from now,

 

[Dids]

I think it is very logical to assume that Tesla is intending to use aluminum. The 8,000 ton die casting press mentioned in regard to the Cybertruck would only be used for aluminum or some other low melting temp metal.

Investment casting is generally used for steel or stainless. Think of the old-fashioned foundries pouring molten steel into a sand-cast mold. A Gigapress is not be needed for this.

BTW, I don’t intend on canceling my Cybertruck order even though I would definitely prefer a completely stainless steel frame without major cast aluminum components. I just foresee cracked aluminum subframes being discussed on this forum 10 years from now,

Its logical because stainless isn't usually die cast.... but they are making a new press. 8 tons thats 2 tons more force than the parts for model y. Does it really take 2 tons more force just to do a larger aluminum part? Lots of people panned Tesla when they started doing die cast. It is completely possible that they are doing something completely new again.

 

[Owner13669]

Tesla is worrying me with this, do they only expect these truck to be highway driven with the occasional light off-roading, like you might do with a new Range Rover? I hope the decision to go with an aluminum subframe doesn’t diminish the Cybertruck’s durability.

I ordered a Cybertruck to replace my 2012 2500HD Duramax Z71. My truck regularly hauls 10k trailers off-road that stressed the frame to the max.

I had complete confidence that the stainless monocoque frame design would be able to handle this. I do not think a cast aluminum subframe is going to be able to survive this same type of punishment for 10 years.

The problem with worrying about the frame is that there is no frame. There is an exoskeleton. That is what will be carrying the load.

 

[Sonnus]

It is not that hard to read between the lines here. The Gigapress is described as an “aluminum die casting press”. I have experience with investment casting, sand casting, metal fabrication, etc. I have personally worked with foundries designing and manufacturing parts. I have also spent time welding/repairing cracked cast aluminum and cast stainless parts.

It is not feasible to die cast stainless steel. The dies used in the casting process would melt and weld to the part they are casting. It would end up being one massive chunk of scrap metal.

Unless they are going to use tungsten dies? How in the world would they even make those? But even then, molten stainless binds pretty well with tungsten so I doubt that would be viable.

 

[Sonnus]

The problem with worrying about the frame is that there is no frame. There is an exoskeleton. That is what will be carrying the load.

That is exactly what I expected. This is the main reason why the Cybertruck required such thick stainless steel that could not be formed into curvy body panels like a traditional vehicle.

But the fact that the Cybertruck is going to be using a massive cast aluminum subframe means that maybe Tesla is no longer relying completely on the exoskeleton frame.

 

[Newton]

some of the strongest designs in nature (and copied by us) is a lightweight interior structure, with a strong outer shell.

think, something like a honeycomb, or foam beam, wrapped in carbon fiber... super strong and light

 

[VI Tesla]

some of the strongest designs in nature (and copied by us) is a lightweight interior structure, with a strong outer shell.

think, something like a honeycomb, or foam beam, wrapped in carbon fiber... super strong and light

Plus the bottom had to be made of something.
Don't think I ever thought it would also be stainless, although would be pretty cool.

 

[Crissa]

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

 

[jfuesting]

Tesla is worrying me with this, do they only expect these truck to be highway driven with the occasional light off-roading, like you might do with a new Range Rover? I hope the decision to go with an aluminum subframe doesn’t diminish the Cybertruck’s durability.

I ordered a Cybertruck to replace my 2012 2500HD Duramax Z71. My truck regularly hauls 10k trailers off-road that stressed the frame to the max.

I had complete confidence that the stainless monocoque frame design would be able to handle this. I do not think a cast aluminum subframe is going to be able to survive this same type of punishment for 10 years.

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.