Edison2 Very Light Car: Chapter 2

[sheepdog 44]

I've watched it several times actually. My point is that some poorly designed cars require several grand repairs for low speed accidents, while others don't. For example a car that gets side swiped, may require new front and rear quarter panels and a door. The drive components remain untouched, and the car is still drivable. The VLC might clip and expend an outboard wheel (absorbing and deflecting the impact), requiring replacement of the whole wheel assembly, axle, bumpers etc. I don't know if it would be less costly to repair the VLC or a Box car under different accidents. But it's something they should look into. The car is economical in all aspects, cheap to own, fuel, maintain. Cheap to repair would be a good selling point.

http://www.youtube.com/watch?v=E3Aye...layer_embedded

[euromodder]

Originally Posted by NeilBlanchard

What about the VLC is a problem? It is one of the most efficient car designs ever; let alone a 4 seat design.

Trying to sell it off as a 4 seat design is only the beginning of the problem ...

It's not a new path in automobile design, as Edison claim.
It's trying to fit 4 people in a traditional pre-war race car .
The car industry has long since worked out that idea isn't going to float ...

Being only a rolling chassis, it's got no doors on it, and it's already very cramped.
That ain't going to get any better with doors and a roof (+internal liners) on it.

They can talk about deflecting crash energy, but that crossbeam is directly on the passenger cell.
Making a sturdy passenger cell is no big deal - Smart's done that - but it transfers the huge loads to the occupants. Not good either.
If the crossbeam gives way ... where's the wheel going to end up ?


Have you seen or found any crash test pics / videos ?
All I've seen is the alu block they hit - which was fine afterwards, simply because the VLC has far less energy in it than a regular car does.
That's fine for what it crashes into.
But what about the VLC itself ?

Even then, crash testing is only about getting rid of the car's own energy.
IRL, that's not exactly what's happening.
Anything beyond a motorcycle is going to be far, far heavier than the VLC, and carry a far bigger punch.
How on earth is it going to absorb it ?

I'm actually driving one of the smallest cars on the market today.
In Europe where we have a long history of them.
Yet I have severe reservations about the VLC.
In the bigger is better market known as the US ???


As for being practical ...
It's not very wide, not very high.
The aero shape severely restricts internal volume.
So it's not going to carry much either ... nor bulky items.


Starting with a boxfish shape - not unlike your CarBEN - would have made it a lot more practical.
Without sacrificing the efficiency, and giving more spare room to make it safer, more practical and more comfortable.

[euromodder]

Originally Posted by NeilBlanchard

They have crash tested the X-Prize version of the VLC, and it does great. I think that Oliver Kuttner mentions the specifics in the video above.

He mentions it.
But I'd rather see it.
40% offset crashes go well , fine but what with other crash types ?
Like head on.
Rear ending.
Pole test - euroncap and real life would have it go smack between the wheel pods ... ouch.

Also the shape is structurally robust. The wheels and their support structures are able to absorb and dissipate energy.

If the VLC is hit on the wheels ... i.e not too high.
Especially in the US, a lot of vehicles will hit over the wheels, or hit the wheels so high they won't nearly absorb as much energy .
Once over the wheels, there's little to stop them ...

The tube frame will surely be robust enough for the vehicle itself.
I have my doubts about its integrity when something else plows into it though ...

It may look like a roll cage, but a roll cage still has a crumple zone around it - the original car.
The holes in the cage are too large compared to the tubes.
That doesn't just mean the tubes will give way more easily, you'll also get intrusion between the tubes.

More weight means more energy to absorb. In a majority of all types of crashes, higher weight is a disadvantage

More weight is more energy.
But more weight is good when you plow into something lighter.
Basic Newtonian physics.


What I find really strange about Kuttner's talk, is that he praises the advantages of his design elements like the suspension - but then doesn't use these advantages in the VLC ...
Like the extra space the quite ingenious suspension allows.

[P-hack]

There should be a Godwin's law for when the discussion devolves to safety.

[euromodder]

Originally Posted by P-hack

There should be a Godwin's law for when the discussion devolves to safety.

Why on earth should there be ?
It's a pretty valid discussion IMO.

Let's have the pics / vids :

How well does the VLC crash ?
- agains the wall
- against another car (it's so different in design that this needs to be assessed)

[P-hack]

You seem oblivious to the compromises made in this design and want to see how it will do against a tank.

I ride a motorcycle, be glad they gave it any thought. 100mpg, HELLO!?! this isn't the nthc forum.

[Xist]

Originally Posted by euromodder

Have you seen or found any crash test pics / videos ?
All I've seen is the alu block they hit - which was fine afterwards, simply because the VLC has far less energy in it than a regular car does.
That's fine for what it crashes into.
But what about the VLC itself ?

The VLC is a lightweight car, but if you add four occupants, that could be an additional seven hundred pounds, right?

[P-hack]

Snore... boring safety speculation alert. Are you guys actually interested in buying one or just looking out for anyone who might buy one, because they shouldn't have the opportunity to do so if it doesn't meet your safety standards for a 4 wheeler?

[euromodder]

It's marketed as a car, not as a motorcycle with improved survivability ...
If they get it on the market, it'll drive around amidst regular cars, so it'd be nice to know how it'll fare in a collision with one of those before learning the hard way.

I'm not oblivious to the design compromises, I'm baffled by them.
It's almost like they're building in so many compromises that it's doomed not to succeed ...

[RedDevil]

I'm with Euromodder.
Edison suggests the VLC may be safer than other cars in many aspects.
I very much doubt that can be true.

The problem with many cars in the last centuries prewar era was that their solid beam frame made them too stiff. Even though those cars could withstand a collision relatively well, the people inside them were subjected to huge G forces and often were killed just by that.

I dream of making a lightweight car. It will have a stiff frame and body, but the chairs will be mounted on a frame that slides with the blow in case of an accident just to manage the G forces. The car needs to be far roomier than the Edison or there would be nowhere to slide to.
A light but stiff car with little space for the passengers to move about sounds like a death trap to me.

It is okay if you know the risks like a biker does; if you would still drive it that's your choice. If they tell it is obviously not as safe as an ordinary car, fine.
If they say it is safe without definitive proof then I'm not convinced; it goes against my logic.
It can be nowhere near as safe as the oh so heavy and spaceous Tesla model S.