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Tesla Model S Gets Titanium Underbody Shield, Aluminum Deflector Plates
An anonymous reader writes "Tesla Motors made headlines several times last year for a few Model S car fires. Elon Musk criticized all the attention at the time, pointing out that it was disproportionate to the 200,000 fires in gas-powered cars over the same period. Musk didn't stop there, though. He's announced that the Model S will now have a titanium underbody shield along with an aluminum bar and extrusion. He says this will prevent debris struck on the road from breaching the battery area. Musk offered this amusing example: 'We believe these changes will also help prevent a fire resulting from an extremely high speed impact that tears the wheels off the car, like the other Model S impact fire, which occurred last year in Mexico. This happened after the vehicle impacted a roundabout at 110 mph, shearing off 15 feet of concrete curbwall and tearing off the left front wheel, then smashing through an eight foot tall buttressed concrete wall on the other side of the road and tearing off the right front wheel, before crashing into a tree. The driver stepped out and walked away with no permanent injuries and a fire, again limited to the front section of the vehicle, started several minutes later. The underbody shields will help prevent a fire even in such a scenario.' Included with the article are several animated pictures of testing done with the new underbody, which survives running over a trailer hitch, a concrete block, and an alternator."
Is he saying they've upgraded safety to piloted weapon system levels?
Help stamp out iliturcy.
This happened after the vehicle impacted a roundabout at 110 mph, shearing off 15 feet of concrete curbwall and tearing off the left front wheel, then smashing through an eight foot tall buttressed concrete wall on the other side of the road and tearing off the right front wheel, before crashing into a tree. The driver stepped out and walked away with no permanent injuries
Sounds like a scene from "the A team", where I would have been saying "that's so unrealistic"!
Isn't titanium pyrophoric, sort of like those golf clubs?
We're here dealing in the realm of engineering + political risk = decisions.
There is a risk, but you can't say it was an engineering risk and just a political one.
I thought it was pretty funny as an absurdist thing. "Yes, our car caught fire after crashing through a wall at 110 MPH, an unfortunate weakness in our battery-powered vehicle which any other car would have obviously brushed aside - the driver was fine, by the way." / "Yes, our cars catch fire after merely crashing through a wall, another wall, and a tree, after which the driver walked away...we suck :( "
"These people look deep within my soul and assign me a number based on the order in which I joined" --Homer re:
This sounds like something yon might see if you're watching Road Runner
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the vehicle impacted a roundabout at 110 mph, shearing off 15 feet of concrete curbwall and tearing off the left front wheel, then smashing through an eight foot tall buttressed concrete wall on the other side of the road and tearing off the right front wheel, before crashing into a tree. The driver stepped out and walked away with no permanent injuries
I can't be the only one who finds this amazing. People survive these kinds of crashes, but to be able to get yourself out for the vehicle and walk away on your own is impressive.
If you have to ask, you weren't going to buy one anyways.
You know, I usually detest any sort of PR speak. That sort of bullshit where they desperately try to spin negative news to their advantage. It's just something I've come to expect from corporations and politicians.
But this?
We believe these changes will also help prevent a fire resulting from an extremely high speed impact that tears the wheels off the car, like the other Model S impact fire, which occurred last year in Mexico. This happened after the vehicle impacted a roundabout at 110 mph, shearing off 15 feet of concrete curbwall and tearing off the left front wheel, then smashing through an eight foot tall buttressed concrete wall on the other side of the road and tearing off the right front wheel, before crashing into a tree. The driver stepped out and walked away with no permanent injuries and a fire, again limited to the front section of the vehicle, started several minutes later. The underbody shields will help prevent a fire even in such a scenario.
That is some mighty fine PR smackdown.
Sure, there were other fires, but this one they got covered.
Can we please move to the post-bullshit era where authenticity is expected?
What happened to the 3D printing revolution?
It's more of an evolution than a revolution. Give it time. But it still won't be the right tool for every job.
Agreed... carbon fiber has a brittleness, and while more sturdy than porcelain, exhibits some of the same behavior of cracking rather than absorbing any impact.
The price is always right if someone else is paying.
Um, I think you need to get some materials science 101 into you, buddy. I've read a lot of your posts and you sound like a misinformed, excited teenager. The fact that carbon fiber ISN'T tough is the reason your F1 driver can walk away. You want to see TOUGH? In the 1960s they built race cars like airplanes. Light AND tough, every accident turned the driver into jelly and the cars survived.
That is small. I suspect that means that either the weight of the impact shield is negligible compared to that of the car, or that the improvement in aerodynamic efficiency negates the losses to increased mass.
Now that I think about it it seems kind of odd that most cars *don't* have an undercarriage shield, even if only plastic - think of how much engineering effort is spent on improving the aerodynamics of the body, which accounts for less than 3/4 of the surface area. Meanwhile the undercarriage is left completely unoptimized, despite having to deal with not only normal aerodynamics, but ground-effects as well.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Carbon fiber has a failure mode that you could describe as "explosive". It absorbs a lot of energy, which is what the race car driver wants, but it doesn't necessarily prevent a sharp object from penetrating the area, which is what Tesla wants.Titanium has incredible toughness given its weight, which makes it a good candidate here. It's expensive, but in a $100,000 car, so what?
Anyway, there's a reason that the A-10 pilot sits in a titanium "bathtub".
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
Most German cars (which is who Tesla competes with) have undercarriage engineering for reasons of sound and high-speed aero concerns. They are expected to sustain 200kmh, and the relevance of drag rises exponentially with speed, but also, controlling airflow is important so that the car doesn't have too much high speed lift. What you do NOT want is a vehicle that loses significant grip as speed rises, yet most cars are shaped like (poor) airfoils so this is a concern.
You may recall that the first gen Audi TT did not have a rear deck spoiler, but real world driving showed that there were many high speed loss-of-control accidents with the vehicle, so a rear spoiler was fitted later.
My opinions are my own, and do not necessarily represent those of my employer.
This. One of the unsung heros of the late 20th Century and beyond are the automobile engineers. Modern cars can take an enormous amount of impact energy and distribute it away from the passengers. It's actually unusual to see serious injuries in major car crashes - it certainly happens but not to the frequency it did previous to energy absorbing frames, airbags, active tensioners and the like.
No kaboom.. No earth shattering kaboom. But you can't have everything.
Faster! Faster! Faster would be better!
Cost and strength. You can extrude something for a fraction of the cost of 3D printing or milling. You can even extrude titanium if you have a big enough press. (google "heavy press program" if you want to see some MONSTER presses.) Both extrusion and milling still have strength advantages over 3D printing. Where 3D printing shines is prototyping, small run, or fancy designs that are too difficult to extrude or cast or mill. But give it a few more years. The other methods have been around far longer, so we know how to do things well.
Haven't they already broken the safety tests by being beyond the test limitations?
Let's see, they had to come up with extraordinary measures in order to flip the Tesla for that safety test, they broke the crush machine at somewhere around the equivalent of 4 teslas stacked on top of the roof.
Thus far the Tesla has taken full advantage of it's electric design to make a vehicle that sneers at standard impact tests.
I don't read AC A human right
I don't understand why people see every new bit of technology like it's some magical panacea, ready for mass consumption the instant they learn of its existence.
You wouldn't try to print 100,000 books on an ink jet printer. While you might do mockups on that ink jet, you'd have the actual run output on a printing press. 3D printing is the same exact thing. Great for prototyping, but too slow, inefficient and expensive for mass production. That may change some day, but currently were a ways away from that being feasible.
I think I know the accident you speak of - it wasn't so much a 'metal spike' as a caltrop in the form of a trailer hitch on the road - One of those 3-ball types from some reports. I don't think it really weighed 50 pounds as I think it was a hitch like this one, putting it closer to 40 pounds(or less), given the shipping weight of 44 pounds.
As for mild steel - not unless it was bought from some shady chinese store.
That's basically what it amounts to. If you see a rusty trailer hitch in the road, try not to hit it so hard that it lifts your car up into the air.
I'd tend to say 'try not to drive over stuff, especially big bits of metal'.
I don't read AC A human right
Did anyone else notice those seem to be successive tests on the same car? In the alternator test you see a fastener toward the back of the belly plate gets loosened, in the trailer hitch test you see the fastener actually come out, then in the concrete block test you see the belly plate actually flap under impact, and you can see what appears to be the hole that fastener came from.
I am fairly impressed that, not only did they do real world tests (which do fall short of shearing off wheels and battering through concrete walls) but they apparently did not put the car on a lift and return it to perfect condition between successive tests.
That makes the test a bit more real world like, cars get driven and accumulate wear and tear, so they are not necessarily going to be in factory mint condition when they hit something.
You get the feeling, regardless of what you think of Musk or the car, that he is very proud of that car, and it appears justifiably so. Yes, he is defensive when the press screams disaster and trumpets doom and gloom about the car, but he doesn't ever try to hide from the press or try to spin the reports, instead he makes a change to improve the car, then does his spin on his own terms.
Obviously titanium might be a bit pricey for the "cheap" Tesla when it arrives, but I bet the anti-penetration armor design will be there, even if it ends up being constructed of less expensive materials.
In this way the response to the overhyped Tesla accidents and fires will help us all in the long run, just like the German automakers pioneered crash simulation in the 80s and 90s, and now all cars have crumple zones.
"Proximity to wonder has blunted our perception and appreciation of it" --Tim Hartnell in 'Exploring ARTIFICIAL INTELLI
Yes, "toughness" is a technical term that refers to how much a material can yield before it breaks. In that sense, carbon fiber is not considered to be tough at all.
Crash structures that use CF normally depend on it's tendency to shatter violently at failure. If you watch any recent F1 crash that damages the monocoque, you'll see an explosion of debris -- this is by design. Done right, you can use up some of the crash energy as kinetic energy in the debris. Unfortunately, this is extremely difficult to design and test. It's also more or less a one-time use thing, I would worry that day to day bumps and scratches that happen on road vehicles might reduce the effectiveness of the structure.
The undercarriages of F1 cars are a little different, they generally have an aerodynamic undertray protected by a layer of kevlar (or similar material). This is good at reducing damage from occasional contact with the road surface and minor debris, but it depends on the undertray's ability to flex at impact and has to be replaced fairly often.
It is Tesla's indifference to the customer's safety that makes this car a death trap. Somone ever so gentily nudges a barrier (an old one that crumbled for 15 feet) at a relatively slow speed of 110 MPH and the two front wheels fly off and the car is flung in to a tree. All we hear from Telsa is "Save the batteries, save the poor batteries". What about the driver? Who is looking out for him?
The safest car ever built was the Yugo. A 200 pound car with a top speed of 15 MPH; how much damage can you do?
That's not exactly right. Nobody corrected you that quickly.
So the folks in the other involved vehicle(s) will be quickly torched by leaking gasoline ignited by the long-lasting sparks from the shield designed to protect the rich man's batteries. Aces.
That's only six stacked on the roof of one, and Volvos are lighter than Teslas by about a 2:1 margin.
www.wavefront-av.com
Battery swaps aren't a dumb idea. If you want to recharge your electric car as fast as it takes a gas-powered car to refuel, that's the only way to do it with current tech. This doesn't mean it'll actually happen though; economic and regulatory problems could prevent battery swaps from ever becoming an available option. Technically, they make perfect sense.
When the Empire State Building was designed, it was planned that dirigibles would dock there and people would be able to get on and off from the deck on top of the building. That of course never happened, but the building was designed with that capability in mind, and it wasn't a dumb idea; dirigible travel would really be nice in a lot of ways, but various problems prevented them from becoming a common mode of travel.
Printing presses are also increasingly under pressure (no pun intended) by start ups like Lulu that essentially print books on demand.
I have no problem with your religion until you decide it's reason to deprive others of the truth.
It's not a Faraday cage, but lightning does use the skin effect for most of its charge, and thus goes over the surface of the car. However, this doesn't work so well with the huge number of cars on the road with a non-metal skin.
You are usually okay if your car's skin is metal, you don't happen to be touching anything in the interior at the time, and if nothing in the car catches fire due to the strike.
Yes, you should use technical terms, and "toughness" is indeed a technical term. From Wikipedia:
"In materials science and metallurgy, toughness is the ability of a material to absorb energy and plastically deform without fracturing. One definition of material toughness is the amount of energy per volume that a material can absorb before rupturing. It is also defined as the resistance to fracture of a material when stressed. Toughness requires a balance of strength and ductility."
Diamonds aren't very tough. They are extremely hard however. Hardness != toughness != strength.
You people need to take a Materials Science class.
Extrusion *IS* "3D printed" with a massively parallel head that can print the entire cross-section all at once. It has been optimized to "print" something with an uniform cross-sectional area. Same can be said about pasta machine. :)
Welcome to Tomorrow done yesterday.
There are a lot of Audi TTs and few corvettes on the German market, where it is legal to drive that fast (at certain places). Add to that the "Deutsche Grundigkeit" and it doesn't seem a big surprise they added that spoiler. Conversely, IANAL, but I think if you were to sue Corvette in the US for loss of control at 120mph, you'd probably walk out of court with nothing but the speeding ticket of your lifetime.
Extruding aluminum tends to be stronger than cast aluminum. I imagine 3-D printed aluminum is not as strong not to mention it is a lot more expensive and much faster.
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Can we get slashdot off Musk's nutsack please? This nutswinging on Musk and Tesla is the greatest car ever is horseshit is getting old. Now he's changing the design great, work the problem Elon. Let us all know when your cars don't catch fire from just sitting there.
What? Like a Porsche GT3? You speak as if gas powered vehicles don't randomly catch fire all the time, and nobody says boo. Troll.
I remember the ad, and quite some time later the reality.
The Volvo(s) had help.
From a quick google search:
1971 Volvo print ad emphasizing roof strength. Called "Stacking," the ad showed six Volvo 144s stacked atop a seventh. They were real Volvos, but the impressive stack had help. Each of the six stacked cars rested in a wooden cradle that evenly distributed its weight across the top of the car immediately beneath--and also helped keep the stack from toppling over and ruining some hapless photographer‘s day.
http://autos.aol.com/article/s...
No brain, no pain.
Next up: CowCatchers on the Tesla X!
Confirmation bias. You hang around someone intelligent people, you fail to recognize the rest of the country is bat-shit stupid.
Aluminum sucks for wheels which are at risk of impact, no matter what kind of vehicle you're talking about. That's why you often still see steel wheels on 4x4s even now that aluminum wheels are cheap. But CF spokes with a steel rim would be all right. That way your rim wouldn't explode if you ran over a curb or a rock.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
You need either a materials science class or a reading class...
Diamonds are not tough in that they can be crushed and they do not appreciably deform.
Anvils are tough in that they can be repeatedly hit with a hammer, which will create dents etc. but will not fracture the metal.
Is 1563649 a prime number?
50k tons is indeed huge,
Huge isn't the word. The battleship USS New Jersey is 58,000 tons, Empty its 48K tons. Can you imagine bench pressing a battleship?
It would only take one incident of scratching the wheel on a curb and a CF-spoke rim would be trashed.
That's only true for wheels with a massive offset (I always get which is positive and which is negative wrong, so uh, outwards.) And while those are in the majority today, some sort of protective hubcap could be used. It could feature transparent elements to show off the CF for markets which desire that sort of thing.
So you're not likely to see any CF-spoke wheels for roadgoing cars, except maybe from some aftermarket companies that include giant warnings and disclaimers.
I suspect that eventually someone will come up with a clever way to determine whether the CF is failing. Some sort of capacitance test through an edge connection (conductive epoxy?) is my gut instinct. If you could detect both conductivity (fiber failure) and leakage (epoxy failure) you'd really have something. Probably an astronomically expensive part.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
When Tesla examined the car, they found the fire had not touched the battery, the charging system, or the electrical connectors. In other words, all of the parts of a Tesla that could cause a fire weren't involved in the fire.
Something is fishy about the owner's claim of the fire starting spontaneously in the car.
I think I've seen her on Plenty of Fish.
Mostly random stuff.
I think you might have written the best advertising material for the car so far.
Why? What happened? Isn't carbon fiber the magical Space Elevator material of the glorious 3D printed future?
Carbon fiber or carbon fiber reinfoced polymer are not the same thing as carbon nanotubes. For example, carbon nanotubes have 15 times higher tensile strength than carbon fibre. I couldn't find toughness numbers for carbon nanotubes, though. And we can't really make anything large with nanotubes yet (not without losing most of their strength).
>You have to manage an inventory of expensive $20k+ parts that could be stolen,
All inaccessible and underground. They're also fairly useless to thieves; who would they sell a stolen Tesla Model S battery pack to?
The battery packs are heavy, unwieldy, and can't be resold to anyone. If you're a thief, there are much better targets.
>you have multiple sizes and model of battery,
All the loaner packs can be the same size and model.
> and different wear states. The batteries lose power constantly.
Since they're at the charging station, they can keep the batteries topped off. As they wear out, they'll be replaced. Tesla owns the loaner packs. The battery swap is actually a loan, not a true swap like propane. You have to go back to that station and get your original pack back.
>You have to manage liability, if you install a defective battery and it catches fire who pays.
Tesla, since they're both the manufacturer and the battery swapper.
>You have complicated machinery that you need to have many of to handle rushes that go unused at other times
It takes 93 seconds to swap batteries. http://www.teslamotors.com/bat...
They really only need one swapping machine on site for the foreseeable future, and if they get to the point where they need more swapping machines, then they're doing very very well.
Especially since swapping isn't going to be used day-to-day; you'll charge at home or work. Swapping is really only for long-distance trips.
>And you still need to have the same order of magnitude of power available to charge up the swapped out batteries as you would to just charge them in the car.
Of course. The advantage of battery swap is that you can run out your current battery, swap at the station, drive wherever you're going, come back, swap back for your now-recharged pack, and go home. 186 seconds during the trip, versus having to stop and charge for a few hours.
That's not a metal screw, it's a plastic pop fastener designed to hold plasticy bits in place.
Karnal
We had a couple of 700-ton presses around here. They looked like they were very precisely designed to fit in a semi trailer and not have room left over (and that's probably how they were designed). Scale up by a factor of 70.
"When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
My 1997 BMW 5 series (the Tesla competes with the 2014 7 Series) has a thick plastic underbody shield. It was designed in ~1992 and started production in Europe around 1994. So it's not a new concept. It also still gets 33mpg @ 70mph on the highway from Dallas to Houston and isn't a diesel.
moox. for a new generation.