Hi Peter and All,
--- Peter VanDerWal <[EMAIL PROTECTED]> wrote:
> I have a rather ambitious project to build a
> (mostly) ground up EV with
> a fiberglass body. Since fiberglass doesn't offer
> much crash
> protection, I want to integrate a roll cage into the
> foam/fiberglass body.
I wonder how many F1 drivers would agree with you
that composites are unsafe.
Steel does not work well with composites and will
raise your structal weight 50%+ without making you
safer.
How about an experiment. Buy a yard of woven
roving, take out the strands and make a 1/2"x1.5" bar
with a good iso- not ortho-polyester, vinylester or
epoxy resin, then try to break it after it cures well.
This is how they make aircraft roll cages, landing
gear springs, main wing spars for Rutan's airplanes.
I find steel roll bars very dangerous in the
cabin from hitting your head on them in an accident.
To avoid that the EV would have to be a lot bigger to
allow enough headroom from the roll bar to be safe.
Of course the best place for a roll bar is right
above your head. I've done the inside roll bar and
never again. Smooth inside body for me for safety.
The composite rollbars can be built in between
the composite skins by hollowing out the foam core
where you need protection.
>
> What I want is adequate protection should the
> vehicle flip at 65-70 mph.
Works for the F1 racing guys in 200+ mph crashes.
Look up the Horlacher EV's and their test of a
Think size composite EV head on into an Audi 5000, and
the Horlacher wins!!! They use a similar glass
structure in it. A site anyone interested in small
EV's should see.
They have about 10 mostly EV composite proto-types
with a lot of good ideas. Too bad they never put any
into production.
>
> Can anybody recomend a minimum tubing size, or a
> good book (or website)
> to read on roll cage design?
Most race cars use 1.25" thin wall tubing with
more of them rather than a few larger ones now.
Remember you only need to design to the EV's
weight because all the force that can be put on it
would be would be that weight. Any more force than
that and it will just move out of the way.
Most important in this kind of safety system is
to be well belted in or you will just hit the inside
body as fast, hard as what hits, rolls you.
The reason most people die in SUV crashes is
because they think they are safe in a big vehicle and
don't buckle up. They crash around the interior
getting badly hurt and/or thrown out. So wear your
seat belt!!!
We want to keep you around,
jerry dycus
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