Tesla's Cybertruck Approach on Auto Manufacturing and Engineering | Hacker News Reader

Tesla's Cybertruck Approach on Auto Manufacturing and Engineering

motortrend.com

79 pointsfumar69 comments

This was the most compelling explanation of the visuals. They are saying that Telsa put function radically over form to reduce manufacturing complexity and efficiency. This is a purely utilitarian approach that is not self-evident.

I hope Telsa will put together a better presentation to explain this to the public. This is the sort of technical progress you'd like to see in other domains.

These are mostly old manufacturing ideas which affect crash safety; repairability, an street legality.

It reminds be a lot of the DeLorean.

Could you please explain how it affects those things? I'd be very interested in learning about that.

I can't speak towards repairablity and legality, but I know cars are safer now than they used to be back when they were made of steel, because they crumple which absorbs the impact of crashes. Rigid steel transfers the impact to it's occupants.

I'm eager to see how this thing performs in crash tests.

Ah that makes sense. I'm interested to see how it performs there too

Yes they affect them, not all in a negative way.

unconvinced. long, precise, sharp angles are expensive to stamp on thick steel plates.

so I've checked around the pictures, apparently the marketing material has seams along the angle, but the car in the presentation has angled plates.

something doesn't add up https://imgur.com/a/HO1HnGC

I figured they would be using a brake[0] for the bends.

[0] https://en.wikipedia.org/wiki/Brake_(sheet_metal_bending)

yeah but that doesn't make really sharp angles and controlling the curve where it bends precisely is hard, fighting that is going against the claim it's about manufacturing efficiency

Point well taken.

There are multiple dimensions to manufacturing efficiency, though, right? I have no appreciation for the cost of a couple dies and a machine for stamping versus the cost of a CNC break with one die, but it may play a part based on the number of units they think they will sell. (1,000? 10,000? 100,000?)

If starting with super hard cold rolled steel, it’s most likely impossible to “stamp” using traditional progressive stamping dies. The deformation has to exceed the final shape and via springback the final shape is produced.

Springback is possible on a press brake when folding along a single straight line. If panel needs a 30 deg bend, then bend it to 40, and it pops back 10 when off the press brake. As an example.

That quickly gets impossible to do when you start bending around complicated 3D contours.

That's a lot slower than stamping from sheet and has all kinds of limitations with respect to angles and manufacturability. I've used them a lot making sheetmetal enclosures for industrial hardware, it's great for simple stuff, right angles and other common shapes but if you start doing sheets that have multiple bends at precise angles at odd angles to each other you'll run into the geometric limitations very quickly. Keep in mind that the wedges need to cover all of the angle for the brake to work and that you need to be able to remove your work without disassembling the tool.

This is a more likely option:

https://www.247tailorsteel.com/en/plate-bending

These machines will do full sized sheets as well and are much more versatile than a brake, also far faster.

I believe that is a type of brake, a press brake.

Ah ok, I do not know the name for that particular tool but I've seen them in use for sheetmetal bending in large quantities.

The device the OP linked to is meant to be hand operated and only for small series. Setup takes forever and then some, redoing a setup for another batch is impossible because it will all come out slightly different.

That 'press brake' uses a tool-and-die style mechanism to deform the sheet, very accurate and highly repeatable, quick as well, cycle time is a few seconds.

Is there any reason they wouldn't just make those independant panels and weld those joints? It's a little slower than stamping, but cutting and welding panels like this is well within the capabilities of their existing robots.

From what I understand, the outside of this car is bare stainless steel. Can humans or robots make welds that don’t show Up as ugly warts on the outside? If so, can it be done cheaply enough?

Fair enough. I supposed the structural weld could be on the inside to hide the bulge. But you'd need some tight tolerances for that to look good from the outside.

Order of magnitude cheaper to start with flat sheet, lasercut/waterjet/stamp out final shape, and bend.

They are starting the cut and bend operations with the fully hardened steel, so there is no post stress relieving / aging / finishing. It's about as simple as it can get for metal fabrication.

Welding also fundamentally changes the underlying steel properties. I'm not up to speed on full hard 301 SS, but most likely any thermal operation will degrade it's mechanical and chemical grain structure.

Saw this on Reddit. Seems to show a panel there which opens up. I don't think we can trust anything but the major bullet points making it to production though. This thing is a prototype and much of what we see could be up in the air.

https://imgur.com/a/r4drdJh

Basically: the stainless steel, hard edged design has quite a few cost-savings for manufacturing but may effect aerodynamics, weight, and durability (large flat sections of metal are more likely to dent than curved).

It will be interesting to see how the pros/cons play out for Tesla with the cybertruck!

The whole stainless steel thing is fascinating to me. The other really famous car made of stainless is of course the Delorean DMC-12.

Wasn't that aluminum?

Brushed stainless on the DMC-12. Although now Ford F-150s are getting aluminum bodies.

Definitely stainless. Unlike the rest of the chassis.

https://www.deloreanguide.com/new-posts/frame-rustquite-poss...

"Well, if you're going to build a time machine, why not do it with some style? Besides, the stainless steel construction made the flux dispersal.....watch out!"

I always wanted the rest of that line. As though the writers had thought up some way to make 'stainless steel' a necessary part of the the time machine construction.

Brilliant writing, though— hint that the reason is there without actually filling up the script with made-up gobbledygook. Author Sid Fleishman said that if you had a plot hole in your story, all you had to do was point to it and it would disappear:

----

For example, in McBroom’s Zoo I wanted to use the Hidebehind, a fabled frontier creature. No one knows what the Hidebehind looks like because every time you look, the animal hides behind you.

I saw the hole at once. All McBroom needed to do was to hold up a mirror and he’d see the Hidebehind’s mug. I plugged the hole by pointing to it. Works like magic. “I even tried walking around with a hand mirror.” McBroom declares. “But the Hidebehind was too eternal clever for tricks like that.”

Kinda like the lampshade trope. It's interesting to compare to writing/acting in terms of a product like this. The launch is basically a written and choreographed performance - all done live. And in this case, something went seriously wrong (the so-called armor glass shattered during the live test). What does the performer do to hold a mirror to it (or lampshade on it) to make it go away?

It's actually crazy that it would fail so distinctly in the demo that was supposed to show its strength. Was it the first time they used the metal ball? Had all testing just been done with hammers and crowbars?

Maybe they should really highlight how and why it failed.

> The other really famous car made of stainless is of course the Delorean DMC-12.

the metallic finish made the entire care near un-repairable. It showed flaws exceedingly well, and the properties of most stainless hinder most efforts at regular dent and ding repair.

Aside : I got to smog certify a DeLorean when I was a mechanic in a previous life. It's one of the most memorable cars I have ever had the pleasure of driving. It wasn't that great a driving car, but it was just such a neat image to see in real life.

Wouldn't it be more easy to maintain because you could just sand and blend away defects as opposed to dealing with paint where flaws are more noticeable.

paint can be filled and repainted, bare metal cannot without exposing fillers and ruining the finish.

realistically no one is blending the metal during most repair jobs; the panels either get replaced or bondo'd, sadly -- unless we're talking about vintage or nostalgic cars that have inherent issues with panel supply.

Sounds like their plan for this is just that the panels are super thick and therefore really hard to dent, though I don't know what that means for crumple zones and safety.

Perhaps there's an argument here that the bare metal will acquire a kind of patina, that the accumulation of small blemishes will over time contribute to an attractive worn look? That's certainly not how cars conventionally age, but it will be interesting to see what a Cybertruck looks like once it's got 200k miles on it.

Small scratches, sure, but dents are way harder to deal with on a stainless steel body panel. A dent stretches the metal, so you have to un-stretch and reshape it perfectly, which is time consuming and unless you take it to a shop that specializes in Deloreans no one will know how to do it. Compared to a regular painted body panel, everyone in every body shop has filled a dent with bondo, sanded it flush, and sent the panel to the paint booth hundreds of times. The painting itself can be finicky, but that's where the practice comes in.

Delorean assumed body panels would just be replaced when damaged, not repaired.

For me, I like my tools to age with the patina of use - scratches, knocks and dents. I'd love to see this taken up on a larger scale, but sadly can't rationalise the cost or commodity of a Cybertrunk here in London...!

ed -

* Cybertruck, obviously. Although I'm now working on a SAAS solution named 'cybertrunk'.

> durability (large flat sections of metal are more likely to dent than curved).

I take it you didn't see the part of the presentation where they hit the Cybertruck with a sledge hammer with no effect.

The "regular pickup door" did not fair so well.

So what happens when you get into an accident with this thing? Do you have to replace the entire body? Or does it just not properly crumple and you’ll just be dead or crippled so you won’t have to worry about it.

I would imagine it would probably be similar to any current car, it looks like it has panels which could be replaced. The roof was difficult to tell though, if there was a weld or seam on to top which was part of a larger panel

This is the truck Howard Roark would build. Function over form for good reason and to hell with the critics. I for one absolutely love it.

How is it function over form? They use electric motors on the door handles, bed cover, and ramp. They made the bed sides super high and hard to access the bed. It has no floor tie-downs. They gave it a glass roof where you'd lean stuff from the bed!

This is absolutely form over function, they just picked a form which is controversial.

PS - I actually like the Cybertruck. But I'm self aware to know it is due to all the impractical toys that will ultimately be a maintenance hazard. It is cool but impractical.

Uh it looks like there are at least holes where the tie downs can fit. The glass roof is kinda nuts for sure though. Those high walls are also annoying if you want to put tool boxes in your truck. It might be possible to still be practical by making some changes to how you might store things for easy access like on a normal truck but it probably can't use current existing solutions. :/

If there are re-enforced holes to add floor anchors then that definitely resolves that issue, just didn't see any on the limited press photos released so far (only wall anchor points). Kind of want someone to do a "truck bed review" of the Cybertruck, just loading, unloading, anchoring, etc.

The high sides are for overall stiffness, compensating for the flat sheet steel, which is for cheap manufacturing.

I know, I read the article. We're talking about the utility of the design they ultimately wound up with, the "why" doesn't alter that. Designs are always a trade-off, the question is did they trade-off the correct things to make a really good utilitarian truck?

Sorry, I see your point.

I saw in another article that this is their first prototype, built very quickly, so I wouldn't read too much into details like tie-downs. For the rest, I guess how useful it is depends on the customer; e.g. I saw a contractor comment that the built-in battery power and air compressor would be pretty convenient for job sites. (Of course other electric trucks would at least have the batteries, but it remains to be seen whether they'll match this on price.)

It's function over form from a DFM standpoint, not utility. Case in point, if they cared about utility, they'd quote torque numbers instead of 0-60 times. Not to mention the laughable sides and glass top.

I agree from a consumer standpoint, but the article makes a great argument for the form being very functional from a manufacturing standpoint.

Honestly, I see it as more of an FJ Cruiser or a Wrangler that happens to have a very, very large trunk.

I think a lot of buyers will be people who would normally buy a large, 2-row SUV, or truck owners who keep a cap on their bed.

>Ditch the heavy, traditional, body-on-frame, and rethink the structure as weight-efficient trussed bridge in its simplest load-spreading configuration: a triangle set on its hypotenuse. One side is the Cybertruck's wedgy cab, the other, its tapered, sail-sided bed, their meeting point at the truck's tall peak resulting in a huge cross-sectional area for maximum stiffness.

So one little mishap with a heavy object in the vicinity of the bed rails and the truck's structural integrity may be compromised. All the pros listed to the design seem valid but this seems like a very high stakes bet on exactly the functions this truck does and doesn't need to perform.

Like most luxury trucks this thing probably won't have very many super heavy things coming near its bed.

I was actually prepared to dislike it before I saw a picture of it, because I'd seen other conceptualizations of hypothetical Tesla trucks and they look sorta like they're trying too hard to look like the sedans, but end up too bubbly and cute.

However, this truck is dope as hell and I'd drive it. It makes you look like a retro-80s action star. I think I would have to grow out my mustache if I drove it, and I don't mean that ironically.

It looks like in a couple of ways, though, they maybe did go with form over function.

1. It looks the roof over the passenger compartment peaks over the heads of the people in the front seats, and then lowers towards the back. (See photo 42 of the first gallery in the article, or photo 22 of the second gallery, or photo 10 of the third gallery, or the second photo in the Ars article [1] gallery).

This could get annoying for tall people in the back seats. For a family car, where the back seat will usually be kids, less headroom there is fine. A pickup is work vehicle and so should assume adults in back and so should have adult headroom back there.

2. The walls on the side of the cargo bed are not flat. That angled line from that end to the peak of the roof does look great...but it also means that existing truck campers [2] or camper shells [3] won't fit.

My understanding is that while bed sizes aren't quite standardized, what one manufacturer calls a short bed, standard bed, and long bed will and what another manufacturer calls short, standard, and long will be close enough to each other that a lot of accessories like campers and shells can be designed to work with both.

It looks like the Tesla will need new accessories, which only work with Tesla.

[1] https://arstechnica.com/cars/2019/11/tesla-wants-to-reinvent...

[2] https://en.wikipedia.org/wiki/Truck_camper

[3] https://en.wikipedia.org/wiki/Camper_shell

> This could get annoying for tall people in the back seats. For a family car, where the back seat will usually be kids, less headroom there is fine. A pickup is work vehicle and so should assume adults in back and so should have adult headroom back there.

4-door full-size pickups are the modern giant family sedan. Just look at one with a cap on the bed, and it just looks like a giant 1950s sedan, (edit) only taller

Tesla missed opportunity to describe headroom in backseat. A 6'5" man sat in back seat when asked how much leg room, he said "I have days" [1] and his head doesn't appear to touch glass ceiling.

[1] https://www.youtube.com/watch?time_continue=105&v=-oW-BVxoQF...

The Prius is the ultimate function over form vehicle, and people still complain about its form.

This is a great way to describe it. I love any Fountainhead reference.

And he went to Rearden for the steel.

Why would you need bulletproof glass?

Why would you need an SUV in urban areas?

Because station wagons aren't as profitable for Ford. I'm not even kidding. A lot of groups benefit from increased consumption from this. Auto companies get protection in the light truck segment from foreign competition. Gas companies sell more gas. There is more churn on the consumer loan market as people overextend themselves to buy them (instead of getting more practical coupes or sedans and renting pickups as needed).

Because some of us are tall.

I commute with a 2.5L Golf, I get 25 mpg in urban mountain driving. Stick shift, it's a blast to drive. However, it's also a massive pain in the ass to get in and out of. Especially since my recent abdominal surgery.

When I slip into my SUV I really appreciate the extra space.

When I load all the crap modern children have (car seats, strollers, pack and play, ect) and lug them 300 miles to their grandparents (which I used to do monthly, now once every two months), I also appreciate the extra room.

Speaking of kids, I really appreciate having an extra 1000 lb of inertia (vs. the Golf) protecting them when some idiot on his phone crashes into me. Fellow millennials! Put the phone down!

If (when, really) I move back to CND, I'll appreciate towing 5000 lb trailer worth of stuff to have while the moving companies does their thing.

And you know the best part of the SUV? The Golf doesn't get much better millage! I save more money from the cheaper tires the Golf takes than I do on the gas!

Station wagons, being lower and not outfitted for 4wd, have taller cabins than most suvs. The physics are pretty clear cut. You have not done your due dilligence and are talking without knowledge of wagons.

Working pickups in the wild are subject to lots of sharp impacts that regular cars do not normally get. Glass is a big problem.

>Working pickups in the wild are subject to lots of sharp impacts that regular cars do not normally get.

realistically this vehicle has very few of the traits needed in a work pickup.

Expensive and remote repair, lots of gadgets to break, difficult to remotely fuel, very likely costly compared to the cheapest alternatives.

It's like an anti-Jeep.

This seems to me to be like an electric Honda Ridgeline; a truck made for grocery-getting, mall-hopping, and very light offroad duty.

Also : there are glass formulations that are better suited for tear and puncture resistance than bulletproofed materials. There are trade offs when those materials don't need to deal with the same kinetic energy as a bullet, but i'm not educated enough on the subject to say much more.

Realistically only a very small percentage of pickups or Jeeps, even on the high end, are working vehicles. It's just a different form of virtue signaling.

Nobody has an interest in talking about it, but pickup trucks and truck culture in the US are a marketing driven phenomenon. It stems from the fact that most US auto manufacturers' profit is driven though light trucks as the result of the 1964 chicken tax. They are appallingly impractical and expensive for the most part, and I'd bet 99% of Silverado High Country package trucks doing no more heavy duty than typical suburb traffic, too. I think Tesla has just embraced the world as it is rather than trying to shift consumer preferences.

> Expensive and remote repair, lots of gadgets to break, difficult to remotely fuel, very likely costly compared to the cheapest alternatives.

I really don't understand this argument. Ford/GM/FCA 1/2 ton trucks are in a gadget/gimmick arms race and pretty terrible at executing it. The new 2019 Dodge Ram has been a disaster for new owners. I won't provide references because it is a simple google search. (For bonus points research the ongoing 2020 Ford Explorer debacle). Objective observers give Ford the nod for reliability of the big 3, and that's why Ford can charge about a 10% premium.

And that Ford/GM/FCA builds gadget-full and reliable pickup trucks seems to be a collective delusion of the truck enthusiasts. Toyota Tundra hasn't been meaningfully updated in 10 years and still sells like crazy. Toyota hasn't had to update it with gadgets because it is reliable like all Toyotas. It correspondingly has significantly higher new price (for given features) and resale value than any of the other 3 brands.

Tesla's electric motor drivetrain formula is already proving to be lower total cost of ownership [1].

As for the Tesla truck, airbag suspension is a notorious reliability item from any mfg, they all source from similar Tier 1 suppliers. So maybe Tesla decides to insource this? And that retractable bedcover looks prone to breaking. But besides those, everything else are things Tesla has already proven to be more reliable than ICE alternatives.

As for difficulty to remotely fuel, are there more power outlets or gas stations in the world? Motivated people find solutions to EV logistics and it is getting easier every year.

Tesla has also said the Cybertruck will come with a solar panel option that can add 10-30 miles per day given configuration.

[1] https://www.marketwatch.com/story/this-math-shows-teslas-mod...

The fact that the truck looks like a Warthog from the Halo video games aside, I feel that this truck is destined for the defense market. Overly sturdy frame, bulletproof windows, no gasoline. Electric vehicles that can self-charge through solar seem to be a massive logistical advantage. You can reduce the need for fuel supply lines.

It could recharge through solar in a day or two, if you have a house's worth of panels, and the clouds cooperate.

Imagine deployable solar canvases! Similar to how satellites collect power. In the past two decades, I think this could have been useful. The US deployments were in the middle east (plenty of sunshine) and were mostly fought without a frontline through patrol missions out of bases (plenty of sitting around waiting for something to happen).

Black and white in a work truck..

I think that they used pure white anywhere shows where they expect the market to be.

Aesthetically I like it, it's different and looks like something you'd see bouncing around Mars.

Reply on news.ycombinator.com