The Free Talk Live BBS
Free Talk Live => General => Topic started by: Sam Gunn (since nobody got Admiral Naismith) on November 17, 2009, 10:40:42 PM
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Japan's Eliica may look like science fiction, but with the engine power in its wheels -- all eight of them -- a top speed of 230 mph and a range of 200 miles on a single charge, this electric car has potential in the real world. (http://www.marketwatch.com/video/asset/eight-wheeled-electric-car-from-japan-2009-11-13/E7C648E1-8B46-4911-81DD-A4EEA95D15EA?link=kiosk)
I think it looks kinda cool for a land yacht.
Kinda cool, but kinda wtf.
200 miles is good range for these things though, except for the 10 hour charge.
I'd like to take this thing around the track a few times though.
I guess I since I like 4 wheel drive I should like 8 wheel drive, but it's just so weird!
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I thought that was really cool. 8 wheels is not too weird for me.
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I wouldn't say weird. Atraditional maybe.
Looks great, really.
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Looks great. Hope it actually makes it to market.
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I suppose there's a reason they don't mention the cost. It means that you won't be buying one of these anytime soon.
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I suppose there's a reason they don't mention the cost. It means that you won't be buying one of these anytime soon.
Its a college project; so its not intended for public manufacture.
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I think it looks rad, but I hate 8 wheels. I'm so sick of replacing the 4 I have now.
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20 years ago I was talking to a guy about linear electric motors in the wheels of an electric vehicle
I'm glad someone finally put it into operation.
The problem is not just power delivery, it's battery. Will the establishment in the US allow a non Pb-H2SO4 battery driven car to be produced?
Hmmm.
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It looks like a cockroach with wheels for legs. Given that the big problem with handling is minimizing unsprung weight, I'm betting it handles like shit.
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It looks like a cockroach with wheels for legs. Given that the big problem with handling is minimizing unsprung weight, I'm betting it handles like shit.
Given it has 8 separate motors, and presumably 8 differentials, I bet it can outhandle a subcompact. A normal car by contrast could not have the ability to turn using different levels of power to the wheels on each side to turn.
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With the motors in the wheels, I don't see why it would even need differentials.
Its a college project; so its not intended for public manufacture.
Which means it probably costs millions of dollars. All the more reason we're not going to see it on the roads anytime soon.
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The problem, again, is unsprung weight. You have a hard time turning or accelerating if you don't have firm adhesion to the road. (MikeHz is right, it doesn't have differentials, since the motors are in the wheels.)
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It looks like two Deloreans mating.
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:lol:
But, seriously, I've actually thought about this before. With 8 wheels the acceleration and braking would be mind-blowing!
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...on a drag strip...not necessarily on a "real" road...
There's also more friction from the extra tire surface on the road. It's also exceptionally long--guess it has to be to get enough wheels (motors) under it. Wonder how it tracks in the snow.
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There's also more friction from the extra tire surface on the road.
<< has never understood why:
Force of Friction = fiction coefficient X normal force
Where is surface area in the equation? Why would fatter or more tires provide more traction?
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Force of Friction = fiction coefficient X normal force
Where is surface area in the equation? Why would fatter or more tires provide more traction?
Then why are race-car tires universally wider and larger than "normal" tires, specifically to provide more contact surface area?
I am not disagreeing with you, just pointing out an apparent contradiction to the strict equation. After all in theory, theory and practice are the same. In practice, they're not.
As a motorcycle rider, I cannot tell you if it is just smaller tires, or lighter weight, that makes a bike less sure footed than a car. Just that it happened.
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Tandem wheels worked on this car: http://www.youtube.com/watch?v=dchPW55k6pk
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Force of Friction = fiction coefficient X normal force
Where is surface area in the equation? Why would fatter or more tires provide more traction?
Then why are race-car tires universally wider and larger than "normal" tires, specifically to provide more contact surface area?
I am not disagreeing with you, just pointing out an apparent contradiction to the strict equation. After all in theory, theory and practice are the same. In practice, they're not.
As a motorcycle rider, I cannot tell you if it is just smaller tires, or lighter weight, that makes a bike less sure footed than a car. Just that it happened.
Yeah, this is kinda what I was trying to say. I don't get it. I wonder what makes the fatter tires work.
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Force of Friction = fiction coefficient X normal force
Where is surface area in the equation? Why would fatter or more tires provide more traction?
Then why are race-car tires universally wider and larger than "normal" tires, specifically to provide more contact surface area?
I am not disagreeing with you, just pointing out an apparent contradiction to the strict equation. After all in theory, theory and practice are the same. In practice, they're not.
As a motorcycle rider, I cannot tell you if it is just smaller tires, or lighter weight, that makes a bike less sure footed than a car. Just that it happened.
Yeah, this is kinda what I was trying to say. I don't get it. I wonder what makes the fatter tires work.
More surface area = larger contact patch = more real friction, so handling improves.
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It's been a long time since I've studied friction (like, 15 years.) This web page implies that the component of friction does not change with extra surface area, but the force of friction does...it also explains why treads work better than slicks (more surface mating with the road, a similar effect.) There's probably a better explanation available.
http://www.worsleyschool.net/science/files/tires/andfriction.html (http://www.worsleyschool.net/science/files/tires/andfriction.html)
In addition:
WRT multiple wheels, they're probably making up for less traction due to high unsprung weight by adding wheels, improving the odds that at any time enough wheels have positive contact with the road. The tires are probably softer composites than usual too.
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It's been a long time since I've studied friction (like, 15 years.) This web page implies that the component of friction does not change with extra surface area, but the force of friction does...it also explains why treads work better than slicks (more surface mating with the road, a similar effect.) There's probably a better explanation available.
http://www.worsleyschool.net/science/files/tires/andfriction.html (http://www.worsleyschool.net/science/files/tires/andfriction.html)
In addition:
WRT multiple wheels, they're probably making up for less traction due to high unsprung weight by adding wheels, improving the odds that at any time enough wheels have positive contact with the road. The tires are probably softer composites than usual too.
Yup.
I think another factor in the extra wheels is that the motors are actually in the wheel, perhaps they were having size constraints and to make the car faster decided to just add more wheels. Just conjecture there.
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I think you're right. They might have only been able to get as much horsepower as they wanted by adding more motors, which also meant more wheels. It's kind of a bummer if you think about it, because it probably means you'd have to buy a higher quantity of more expensive tires more often. I'll bet they don't wear as evenly as tires on lighter rims with good springs either (I'm thinking, like a car with a shimmy.)
That, and there are a lot of hidden expenses in battery-operated cars, including the need to recycle batteries (yuck!)
Oh, and...long wheelbase probably means wide cornering, unless the rear wheels help.