Go to a junkyard. Take a look at any car in the lot. Save for the ones that are rusted out, you’ll note that they’ve all got floors. They’re an integral part of the unibody. Then look at a Tesla Cybertruck. It eschews a traditional floor entirely. The chassis has a big ol’ hole in the bottom.
It might seem ridiculous, but going floorless comes with some serious positives for manufacturing that could apply to EVs more broadly. Popular car teardown channel Munro Live takes us through the Cybertruck’s floorless (but not flawless) design, led by CEO and Tesla investor Sandy Munro.
The video focuses on dropping the Cybertruck’s battery pack, which is the key to this whole shebang. It’s not just the battery that’s coming out—it’s half the interior to boot!
Straight In, Straight Out
We touched on this aspect of the Cybertruck when we looked at Caresoft’s teardown last week. Now, Munro and Associates have given us a better look at how the combined design of battery and floor completely changes the way the truck is built.
Traditionally, a unibody vehicle will have a floor and a roof, with pillars connecting the two. The pillars essentially form the frames upon which the doors are mounted. When building the vehicle, everything for the interior has to be effectively loaded in through the holes in the body. Automakers will install interior components like seats through the door holes, for example, and dashboards are often installed through the windscreen aperture before the glass goes in.
The Cybertruck does things in a more straightforward fashion. The body has no floor of its own. Instead, the battery is installed straight up into the body from underneath. Before installation, though, the battery is pre-loaded with a great deal of interior components. In the video, we see a thick foam underlay on the top of the battery, with the Cybertruck’s carpet laid on top. The front seats and center console are bolted on top of all that, the former installed on large cast aluminum brackets.
For comparison, here’s Munro’s look at the Rivian R1T, which uses a more conventional unibody-with-floor design:
This greatly simplifies interior installation for the Cybertruck. Pre-loading all these components on the battery can be done out in the open. This is much easier than installing these components inside the truck. The whole assembly is then pushed up into the truck in one smooth maneuver. It’s much easier than having workers or robots trying to twist and pivot seats into place through narrow door apertures.
Munro reckons it could save anywhere from $600,000 to $800,000 in assembly line costs, though doesn’t specify how he came to those exact numbers. “I don’t know why it is that we never thought about this before… loading the floor in at the same time as the seats and whatnot,” says Munro. He speculates it’s because of the sheer ubiquity of the unibody concept in the latter half of the 20th century. “We never really thought that hard about what could be done as opposed to what we were told to do,” he says.
While the benefits for manufacturing are obvious, one can also speculate as to the drawbacks of such a design. If the battery is acting as the floor, it needs a near-perfect seal to the rest of the chassis to avoid water ingress. This is more important for a floor than for doors, because water on the road splashes all over the underbody. Whether the seal between the two would survive the removal and insertion of the battery is also worth considering.
There’s also a question of structural rigidity. Leaving the floor open is akin to how convertibles lose rigidity by not having a roof. Obviously, bolting in a big stiff battery housing counteracts that somewhat, but it needs to be rigidly installed to do its job well. Effectively, the battery is kind of acting as a big structural brace to tighten up the chassis as a whole.
Overall, though, this could be a way for automakers to build EVs cheaper and quicker than before. It’s worth noting, though, that this same hack wouldn’t really work for ICE cars. They don’t have a big battery mounted under the body, so there’s nothing to act as a bolt-in floor. Of course, automakers could create large stamped floor panels for ICE cars and bolt them up into a chassis from underneath with the seats and carpet ready to go. In that case, though, the benefits are more tenuous versus just building a traditional unibody. This hack makes the most sense when you already have to sling a big battery under the body in the first place.
In Detail
The video gives us a full walkthrough on dropping the Cybertruck’s battery. This isn’t something you can do on your back in your driveway at home. You might be able to benchpress a small transmission, but the Cybertruck pack is simply a behemoth.
For dropping EV batteries, Munro has a new heavy-duty BendPak lifter. It’s a huge flat platform on a concertina jack that can be hydraulically raised and lowered to support a heavy battery as it’s dropped out of a car. It pairs nicely with the BendPak hoists in the Murno shop. Rated for 12,000 pounds, they’re more than strong enough to handle the heft of the 6,843-pound Cybertruck.
Andy Deloy, Munro’s Program Manager, explains where to find all the bolts for freeing the pack. There’s a row of fasteners along the rocker panels and the front lip of the battery, a few inside by the kick panels, and four more are accessed through the bed. It’s a lot of bolts, but it’s a perfectly reasonable amount given the weight and size of the battery.
Julian Aytes, lead engineer at Munro, then explains how the pack was made safe for removal. The main key is disconnecting the low-voltage supply, which de-energizes the battery contactors and cuts the HV supply to the battery’s external connectors. After checking the HV connectors are indeed showing zero volts, it’s safe to proceed. Fully removing the battery involves unhooking several additional connectors, including the blue low-voltage connectors that run to the electric seats. One also needs to consider the rigid aluminum lines that run vertically to the vehicle’s charge port, which are accessed through the bed area.
Examining the process involved in removing the battery, Munro speculates further on the benefits of the floorless design. Speaking on his experience in assembly line design, he believes the bottom-up load-in process could slash the number of assembly stations needed for the Cybertruck. “I think I can load it in one station and maybe run it down in a station after that,” says Munro, speaking on the battery and interior installation. “Two stations, versus maybe, twelve, fourteen, something like that.”
Basically, Munro is saying that the battery pack could be elevated and bolted into the Cybertruck in two assembly line stops at most. That’s with all the seating and carpeting attached, too. Deloy concurs with his assessment. “It’s a lot of time on the assembly line that it saves,” he says.
Munro points out that damage and mistakes in interior assembly are far less likely when it’s a single smooth operation. “It’s just straight up and down,” he says. “That’s maybe one of the reasons why they have 43 seconds per [assembly] station versus everybody else at 60 [seconds]” he explains.
It bears noting that this design isn’t unique to the Cybertruck. The Munro team notes the design is similar to Model Y. As in the Cybertruck, the seats, carpet, and center console all sit on the battery in much the same fashion.
It will be interesting to see if other automakers adopt similar designs in future EVs. It’s another example of Tesla doing things differently to cut costs at the manufacturing stage. Of course, other automakers are all busy implementing their own tricks to find their own edge in the marketplace. The battlefield of auto design has been ever thus.
Image credits: Munro Live via YouTube Screenshot
massive labor saving on the assembly line. this is akin to the old body on frame car production model where the rolling chassis is fully assembled separately from the body and then they drop the body on the frame, tighten 4 bolts, connect some wires, cables and brake lines, and drive away
Is it weird that I saw the impact driver and was like “Hey, the milwaukee M18 with the 6Ah battery!” I don’t have the big driver, but I’ve liked the performance of the tools pretty well. Except the drill, oddly enough, which has some weird issues in the chuck and keeps gouging my really nice bits.
Does anyone else feel uneasy about having a shitload of high voltage batteries under their ass w/ an electric chair, I mean seat bolted to it? No thanks! Just wait til there’s a bad accident- all those chemicals all over occupants and/or Ride The Lightning Metallica style. This is the last piece of junk, I mean vehicle I would ever own anyway…I still can’t believe this thing even exists…what an absolute ugly overweight behemoth
I prefer to seat on a rolling tiny can full of gas… 🙂
Yeah, was gonna say…no option is “risk-free”. It’s just a different risk.
“I, too, would rather be covered in battery acid than burned alive.”
Hey, I drive a Prius. Why not both?
Ha ha yeah…it just seems like things are getting more extreme and trying to point out stuff that most people wouldn’t think of…I mean yeah, they are aware but this is somewhat uncharted territory (well, at least for the cYbErJuNk)
🙂 🙂
Not really? I don’t have one, but it’d take a very odd confluence of circumstances to discharge the battery at high voltage through the chair, and even if it did, the current will be a problem first as it turns steel bolts into fuses and/or gases, and even then what happens is that the lithium catches fire (lithium fires do have a unique smell, I can say that much) or could explode.
So like, maybe if the seats were wired to or might possible penetrate in such a way as to bring the anode and cathode of the entire battery pack. Otherwise you get the voltage between cells that you’ve penetrated, which even then is supremely unlikely – if you swing a machete into 10 9-volt batteries and manage to cut them in the same place at the same time, you’ll have a mess but not necessarily 90V at any point.
Meanwhile, gasoline is a barely controlled explosive that could ignite with cavitation or a cigarette smoked too close to a pump or any such thing. I’m kind of amazed we’ve made it as “safe” as we have, but there’s a sloshy liquid bomb in every ICE vehicle.
Finally, while you made no assertion otherwise, this is the internet and I have spare time so:
Master of Puppets was the better album by far, as Metallica elevated their songwriting while remaining grounded in the roots of thrash. More complex song structures and growing musical proficiency marked the maturation of their sound, bringing in changes to tempo and time signature that successfully bridged the aspirations of symphony and the execution of thrash. Hetfield’s voice in particular matured out of its youthful screech and found range not present in Kill ‘Em All or Ride the Lighting. They were solid thrash albums, but Master of Puppets is a masterpiece, the benchmark. When metal bands want to note their high water mark, the peak of their form, they endeavor to record their Master of Puppets. See, Chimaira’s self-titled album, or Fear Factory’s Demanufacture.
Made for a cool shirt though.
Yeah, thanks for the explanation…just a different type of risk- just trying to think outside the box and point out things that people wouldn’t think of. Yeah, I’m surprised there hasn’t been more problems w/ gas but at the same time it’s been used for so long and glad that most of the problems have been worked out and “most” people are at least smart/responsible enough to be careful w/ gas- also add in that it’s their own vehicle, a way to get to work, and feeling of freedom and able to travel so they take good care.
I completely agree that Master of Puppets was the best- I love all old school Metallica- was just listening to Kill Em All recently. The Black Album is notorious for being controversially right in the middle and yes, it’s not the same but I do love Enter Sandman and was around when it 1st came on MTV and was blown away…also The Unforgiven/Nothing Else Matters which are slower…I actually like most all kinds of music but mostly on the metal and hard rock side. There is one band I’ve discovered that has totally blown me away recently and it’s Insomnium from Finland where a lot of death metal bands are but it’s not what you would think- it’s considered “Melodic Death Metal” and I’ll list my 3 favorite songs of theirs:
-While we sleep (Amazing song)
-Through the shadows
-Heart like a grave
Enjoy!
Hell yeah! I think there’s an Insomnium show coming near to me. I didn’t really know them and so was thinking of giving it a pass, but then again, I haven’t scratched that Soilwork itch in a long time. It would be worth checking them out, especially if they come recommended!
Not going to comment too much on the assembly of the Cybertruck, but I saw my first one in the wild yesterday. My family were mixed between laughing at the absurd design and disgust with the absurd design. I did nothing to dissuade their reactions, as I knew what to expect but was still disappointed that it looks even more silly in real life than in photos. Fit and finish were better than I was expecting, though.
Based on the decisions made elsewhere in the vehicle, I just assumed someone forgot.
With all the talk of “skateboard” platforms for EV’s isn’t the natural evolution of this the entire chassis– batteries, suspension, motors, interior is built as a unit and the body drops on top of it at the end? The same thing but in reverse.
Yeah!
Why not let Tesla explain it.
Basically Tesla wants to get rid of the assembly line, and putting stuff like the engine and interior into an already built body is pretty dumb when you think about it,
https://youtu.be/k4g5Sb-VQo8
I have tried messaging Tesla engineers and they don’t reply!
wow the first EV cab/chassis 😀
Given Sandy’s…ummm…extreme…opinions about fasteners, I assume he was still unhappy about them. 😉
Which is a reminder that you have to keep in mind Munro teardowns are almost exclusively focused on manufacturing cost and they don’t tend to like things designed for serviceability. Which is fine, that’s literally their job, but it does sometimes skew their opinions a bit.
” In the video, we see a thick foam underlay on the top of the battery,”
That’s EPP I tell ya, functioning as temperature and sound insulation as well as leveling. I’ve been out of the biz. for twenty years but recognized it immediately from the circular steam vent impressions that are characteristic of steam chest molding. Good to see it’s getting this application since bumper cores have shrunk to almost useless dimensions due to lack of minimal damage testing.
“Then look at a Tesla Cybertruck. It eschews a traditional floor entirely.”
Yup… Tesla has been doing this with the Model Y a while now. Saves money on materials and assembly time and contributes to Tesla having excellent profit margins.
Things will get even more interesting when they get into the electricals… particularly the battery pack and the 48V low voltage system.
I’m still wrapping my head around the idea that new trucks have carpets, and if you try to remove them it’s a big random wires draped across the floor mess. If you don’t remove the carpet it’s a big stinky filthy mess and hosing it out makes it worse. Why did anyone think carpet in a truck was a good idea?
I could easily go on a rant about “features” that carmakers advertise like they are optional but they aren’t optional at all.
Anyway, having the floor and everything attached to it drop out as a unit seems like a good idea. Does it make it easier to change out the carpet?
Trucks are luxury vehicles and not for work use for the majority of the owners. You can still get work trucks with rubber floors. When I think of buying a truck it’s to put my bicycles in the back and not tools.
I have carpet in my pickup that I absolutely use for work and get dirty all the time. It’s not a big deal as long as you have floor mats and vacuum it annually.
Two words: dairy farm
Okay yeah, I get that. If you regularly walk in poop and then immediately get in the pickup, carpet is a terrible idea. Not super representative of general use though, and this is a problem that can be solved.
I guess the stock shorts were right, “Tesla has no floor”.
Ahahahah
Thank you for the helpful label on Sandy, otherwise when I took apart my Cybertruck and found him, I’d be surprised!
I believe his name is “Salty” 🙂
( If you’ve ever watched one of his vids, you would understand)
I’ve seen how torn apart most unibody vehicles have to be to do serious work through the interior – seats removed, carpet pulled back, dash torn apart, mechanic legs sticking out at impossible angles while they are inverted and headfirst into some crevice.
Once you’ve dropped the floor a few times I’d imagine it would be amazing to work on either the removed floor+interior, or also standing up through the ex-floor while the body is on the lift.
Isn’t this the way type one VWs are put together? It doesn’t seem so radical.
Kind of, yeah
I was thinking the same thing. Only real difference is the entire drive train is attached to the floor pan.
I’ve been wondering why all the skateboard architecture cars don’t install the interior on the skateboard.
The cool thing about starting a car company from scratch is that you can build factories to suit the car as opposed to building cars that you can build in your existing factories. Sort of what Henry Ford did with the model T . I believe the Volkswagen factory was designed around the car. GM sort of did that with the Vega but failed miserably by not paying attention to detail. Sure, it’s nice to have a car that can be shipped vertically while filled with all of its fluids, but only if attention is paid to how it functions as a car.
Some brave soul now knows all that’s needed to Yabba-dabba-do that Cybertruck-Flintstones conversion.
I am thinking pedal powered.
The title of this post sounds like one of Rudyard Kipling’s “Just So” stories (How the Leopard Got His Spots, How the Rhinoceros Got His Skin, etc).
“And that is why the Cybertruck has no floor…”
So how long until we see a Cybertruck body and pack/frame/interior experience a “rapid unscheduled disassembly”?
Spray those bolts well with Krown or Fluid Film every year. Otherwise they’ll be rusty lumps in a few years of salt exposure. Good luck getting the pack out at that point. It’ll be cheaper to total out the truck.
I mean, that’s not a bad idea, but do you spray the motor mount bolts in your car every year?
Please, all my motor mounts are self-oiling.
Perhaps I am no expert, but this seems like it’s great for assembly but a repairability nightmare. Any repairs to the pack and you’re dropping the entire interior.
Somewhere Audi engineers are infuriated that they didn’t think of this first.
Audi engineers are trying to figure out how to adapt this for ICE cars so they can run a timing chain through it.
timing belt
No! NO! Vehicles with timing belts are unreliable! 😉
Vehicles with radiators and timing chains are unreliable
Then Ford engineers will run a oil submerged belt
or one to drive the oil pump only
With timing chain guides made of cardboard.
Its recycled fibrous materials.
Meh I don’t think it’s that serious. It’s no different than dropping the pack in a normal EV, just with seats and carpet on top rather than being a bare metal shell. Hardest part would be making sure the seal is in good condition upon reinstallation. This is all assuming the pack is repairable anyway, the only other 4680 car (4680 Model Y which is no longer being sold) had the inside of the pack filled with essentially fire-retardant expanding foam… recycling was about the only thing you could do with the pack once it reached EoL
Recycling is extremely effective now for batteries, but it would be nice to be able to replace a group of cells vs a whole pack.
Why is it a big deal to drop the interior when removing the battery pack? I don’t know how much interior trim you might have to remove first, but it seems to me like you just do the normal battery removal process and seats come out too, without really adding any steps or labor.
The more things you have to unbolt/unfasten/unseal, the more of a pain in the ass it is.
Well that’s my point, I don’t think there are many, if any, more things to unbolt/unfasten/unseal.
Seats and interior trim ain’t nothing.
But you don’t have to remove the seats to take the battery out, they come out with the battery. That’s like the point of the article.
Of course you’d have to move the seats over to the new battery if you were replacing the whole thing, but it’s four bolts per seat out in the open. I promise the extra 15 minutes of labor will not significantly increase the cost of a full battery replacement lol
Can repairs be done in situ? I’ve gotta imagine most battery repairs consist of swapping out damaged/shorted cells or associated BMS balancers/sensors – is the CT intelligent enough to pinpoint the cell location (geographically) such that a new cell can be installed from below?
In BEV generally the whole pack is generally replaced vs just cells or components due to complexity and time. Individual cell replacement is time intensive. Battery recycling is at a point where they can recover 95% of the materials to reuse them.
These packs are also not designed for serviceability. It’s literally impossible to disassemble them without damage in many cases. And that’s not just Tesla, it’s all EVs as I understand it.
It’s worth noting that in the context of fullsize pickups, you wouldn’t normally compare it to a unibody, and it’s kind of weird that the article repeatedly does compare to a unibody.
Normally fullsize pickups are body on frame, with a floor that is not structural to any other part of the vehicle. Older Ford pickups have large removable access panels in the floor, so it’s not like having unboltable parts of the floor is necessarily that weird.
Tesla has pioneered and or made popular so many technical innovations when it comes to EV’s it’s a shame that Musk ruins it by being a twit.
You don’t have to let him ruin it
Unfortunately his foul musk is already there, and it will stain Tesla as long as he is the major stockholder and decision maker.
This might change if I was shopping for a Tesla, but I find it quite easy to not care about anything Elon says or does.
Yeah, quite so. Musk and his stans are something else, all right. Yesterday I saw someone on Bluesky refer to the Cybertruck as the incEl Camino. I had to clean the coffee off my keyboard, I gotta stop reading such bon mots while sipping my coffee.
Damn them for making me want a Cybertruck just so I can rebadge it. 😛
How do you rebadge something that doesn’t have a badge?
Fair point. I guess I just want to badge it then.