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Made a couple small changes to the Cybertruck. Thoughts?
- Thread starter Cyrusis
- Start date
I don't disagree with you but my point is more
Rule 1!! "We can only design with angles, no curves" Was the primary edict because of the material.
Within that restriction there was a great deal of aerodynamic design but if something made it more aerodynamic but violated rule 1 it couldn't be done thus material/strength considerations were primary with aero coming in later within the bounds of the strength/material box
CoyoteJim
Member
I’m not, just found his article while searching for anything Elon may have said about the aerodynamics. From what I have read from a variety of sources, there are three main reasons why the design can’t be changed for aesthetic preference:
1) the steel and the glass were already developed for SpaceX, and the steel is too thick for a press. Leveraging these products they’ve already developed to cut costs dictates the angular design.
2) the frame provides the strength, both for payload and for towing. The body is basically two A-frame trusses driving down the street - start cutting into the trusses and you weaken the design, so the sail pillars can’t be removed.
3) given the first two constraints, the shape has been tweaked to be as aerodynamic as possible while still allowing six people and 100 cu ft of equipment to be carried.
With that you get some really incredible features for the price...it just doesn’t match everyone’s 100-year-old idea of “truckness.” The design is also not the result of Elon’s vain desire to make a giant movie prop toy for himself and a few other eccentrics who may opt to buy such a thing (at least not solely).
I agree with all your major points. The one thing I'd add/adjust is about stamping.
It isn't really about the thickness, though that's a factor. Stamping metal involves stretching it - what the industry would call cold-working (because you're reshaping it at low temperatures, after the matrix is fully set up.) Stainless steels generally aren't very ductile - they don't react well to cold working, and are more prone to cracking. (I think it's the chromium and nickel content that drive this, but I'm not enough of a metallurgist to explain that part in detail.)
But this isn't just any stainless steel - this is cold rolled stainless steel... They've already cold worked it between rollers to align and stretch the grains, giving it awesome mechanical properties in the right directions - and reducing the ductility still more.
You could undoubtedly build a special press that delivered enough force to stamp this thickness and material (though it certainly would require more pressure than your typical stamping die) - but the material would fracture as it gets forced into shape.
I understand those side wings are hollow and will also open for storing items. For a contractor this is where you could put smaller things you use all the time like a tool belt. I watched a plumber with similar side boxes on his truck use them to store various pipe connectors. He put the pipes on top. I assume you could put those pipes in the bed and if they were long run then into the cabin via the center rear seat pass-through. That would deter theft of the pipes since they would be under lock and key.
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PACEMD
Active Member
CoyoteJim
Member
Is there a pass-through? I’ve read this referred to a couple of times but can’t find anything official on it. The tonneau rolls up bellow the rear window, so even if there is a pass-though I can’t imagine that it would be very tall or very useful.
Literally this, and only this change is all it would take for me to buy it outright. I don't understand how they could miss this opportunity, honestly, that photoshopped truck is the most gorgeous truck ever imagined IMO. They were SO CLOSE TO PERFECTION. Please see this Elon.
for like the millionth time because if this truck built this way was shaped like that it wouldn’t be structurally sound
it could be . . .
Honda engineers figured out to eliminate the sail panels on the new Ridgeline. Different scale - sure - but they eliminate the sail panel. I’m sure the Tesla folks can figure out a way.
I doubt the shape is absolutely necessary for strength or stiffness (there are plenty of other ways to make a truck like that strong enough without the high sided bed). The shape is all about the aerodynamics which are necessary to obtain the desired range at the given price/weight.
Personally, I would trade off some range for a more traditional cab and bed configuration similar to the OP's concept (see also my avatar).
Better yet, make the sloped back an optional topper - then people can make that tradeoff decision themselves.
CoyoteJim
Member
I don't think it's all about the aerodynamics. The Ridgeline is a unibody, but it can only handle a 1500 lb payload and tow 5000 lbs - the CT can handle 3500 lbs and tow at least 7500 lbs. Part of it's strength reportedly comes from the triangle truss unibody shape.
A typical conventional pickup can haul 3200 lbs and tow at least 10,000 lbs. The front and back halves of the truck are connected only by two C-rails that are only 6 to 8 inches high. The thickness of the metal in the rail looks to be about 1/8 inch or pretty darned close to 3mm (effectively less on my rusty 15 year old truck). In other words, the frame rails of a conventional truck are about the same thickness as the skin of the Cybertruck yet they are only 6 inches high. You don't need a 24 or 30 inch high cross section of 1/8 thick steel to make it enough strength.
Stiffness is another story. There, the Cybertruck design is much stiffer. Which leads to better ride due to more effective suspension damping. Yes, chopping the sails down will reduce the stiffness some. But it will still be plenty strong and stiff.
CoyoteJim
Member
Yes, but you are comparing a body on frame truck to a unibody truck. The CT uses a unibody also to make it lighter than body on frame, probably by 15-20%. I imagine this is how they get away with offering an EV truck with a heavy 100+kWh battery at the same weight as an F150. Can you name any F150-sized unibody trucks that can haul 3200 lbs and tow 10,000? Anyway, 200,000+ people (including myself) are fine with the way it looks so I don't think they are going to make your suggested changes.
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Except it is necessary. The cybertruck is not constructed in a way even close to any truck you’ve ever seen. It’s not unibody or ladder frame not even close to either
except that that’s not a valid comparison. The cybertruck is not a ladder frame nor is it Unibody. It’s a monocoque body which is significantly different than either of these despite a lot of people incorrectly saying the cybertruck is unibody it’s not and it’s a very different animal, the strength is in its exterior shape and nothing else the body panels you see on the outside are all that holds it together with maybe a ribbing along the inside so shape becomes extremely important for strength it’s completely hollow when you strip down a unibody it has an extensive internal structure which the cybertruck will not have. For example this is the frame of a unibody Ridgeline
Nothing resembling that in any way exists Underneath the body panels of the CT. Again for the millionth time the Cybertruck is NOT a unibody and the exterior shape and panels are structural
And for those still not understanding unibody does not mean no frame, the frame is integral to other parts of the car body like the firewall, roof, etc. The engine and transmission mounts attach to the unibody as well as things like suspension, But you still have body panels that can be removed like quarter panels, bumpers, etc
a non-unibody car has a body that can be completely separated from the frame, the suspension, engine, transmission etc all mount to the frame not the body in most if not all cases
A monocoque like the cybertruck is different it has no frame the exterior body panels are the only structure with the possible exception of possibly ribs along the inside (this is how it’s often done on aircraft) everything mounts directly to the exterior structure.
Its not a perfect example but think of the monocoque design like the design of a canoe ( this is imperfect because some canoes have the cross braces which the CT may or may not have) but like a canoe all the structure is on the outside
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CoyoteJim
Member
You’re right... something like a “stressed skin” on on a fuselage design? It’s never been done on a truck before so I don’t think you can look at a body on frame design and compare the metal thickness of the frame at certain points with the metal on the skin of the CT body.Except it is necessary. The cybertruck is not constructed in a way even close to any truck you’ve ever seen. It’s not unibody or ladder frame not even close to either
except that that’s not a valid comparison. The cybertruck is not a ladder frame nor is it Unibody. It’s a monocoque body which is significantly different than either of these despite a lot of people incorrectly saying the cybertruck is unibody it’s not and it’s a very different animal, the strength is in its exterior shape and nothing else the body panels you see on the outside are all that holds it together with maybe a ribbing along the inside so shape becomes extremely important for strength it’s completely hollow when you strip down a unibody it has an extensive internal structure which the cybertruck will not have. For example this is the frame of a unibody Ridgeline
Nothing resembling that in any way exists Underneath the body panels of the CT. Again for the millionth time the Cybertruck is NOT a unibody and the exterior shape and panels are structural
In this rendering from Tesla, you can see the CT has a bunch of folded sheet metal inside the door frames, floor pan, roof edges,and pillars that looks a lot like the cabin design of many other "unibody" designs. It has ribs added under the bottom of the cabin for stiffness. The unique part is that the outer front fenders, frunk inner panels, rear fenders, and inner bed sides appear to be used as part of the structure to connect it to the front and rear suspension.
PACEMD
Active Member
Tesla obviously knows nothing about how to design a truck and hasn't even bothered to consider the structural integrity of the design. They just randomly threw a bunch of metal together. I could do a better design job with 5 minutes on photoshop making the Cybertruck look like a real truck. Looking like a truck is what matters. I'm sure everything else in my 5-minute design will work better than Tesla's stupid design.........
TjckTock
Member
Looking at the rendering from Tesla recently linked by @keeney, I don't think the sails can be removed if you plan to tow anything requiring a weight distribution hitch (like an Airstream). That places considerable torque on the hitch and is subject to punishing torque impulses when you drive over bumps. You *need* that A frame if you don't have an underlying frame to attach to. That angle formed by the bed and the cabin on a rigid body without the sails form a stress riser that *will* eventually fail.
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