scott wrote:

> You mean like these:
> 
> http://members.iinet.net.au/~mmckenzie/files/VX_CHARGED_S/ramps.JPG

Yeah.

> The bigger cars are probably at most 2000 kg, worst case is say 70/30 
> front/rear weight distribution, so I'd say max 700 kg on each ramp (if 
> you put the front wheels on it).

Does that really work? I mean, can you really just say "oh, this thing 
has 4 wheels, so each one only takes 1/4th of the load"?

Also, something like a Prius is 3042 Kg (unloaded). I'm presuming they 
make these ramps with a damned wide margin for safety.

> Well it seems to me that there are 4 vertical columns supporting the 
> weight, so probably max 200 kg or a max force of 2000 N in each column.

But can you really do that? Can you really just say "there's 4 columns, 
so divide the load by 4"? Wouldn't it depend on the angle of the force 
being applied? And what about the horizontal elements? They need to not 
bend at the points where they're unsupported as well.

> Rearranging:
> 
> r = (4*I/pi)^(1/4) = 2.3 mm
> 
> So there you go, make it out of diameter 5 mm steel rod and you'll be fine!

Looks thinner tham 5mm to me - but then again, it isn't cylindrical...

Just how strong is steel? I mean, obviously it varies by type, but how 
much load can you typically put on steel without bending/shattering it?

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