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Am i right in thinking that a rubber band powered car will only ever travel as far as the band will stretch?
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NO thats like thinking a trebochet will ony throw it is far as the rope will stretch
Its about stored energy rather than band length and it will roll afterwards as well
Someone may be able to explain this with some actual physics though.
it depends, are they 2.6" or 2.9" wheels
Looks like that one would as the band is captive on the axle.
The band has to captive on the axle, you wind it up by turning the wheels, then release it.
But then unless there's some kind of clutch, (and I don't see on on the pencils there) the band will wind up again after unwrapping and stop the car.
so it cannot roll in addition to the driven rotations
Just have the band release from the axle when it's done. Will roll for ages then.
I made one for a race in school - first past the post format. I turned a cone out of wood which I mounted on the axle, and wound the band onto the thick end first giving a low gear to start off with, and the gear ratio increased as the band unwound. The wooden wheels span a lot, so I put rubber band tyres on them.
I'd have won easily, but on the day the band got caught on the axle and failed to release, bringing my car to a stop mid course.
I remember making one out of Lego, years ago.
Rubber band attached to a swing arm via a gearbox; as you wind the wheels back, the arm slowly lifts, charging the band.
my old Austin Metro was great,bugger to wind up though 🙄
so it cannot roll in addition to the driven rotations
if the band is captive, then depending on how much momentum the car has, it would travel until the band had un-wound then roll onwards winding the band back up again. Then reverse.
[url= http://www.bbc.co.uk/archive/great_egg_race/10801.shtml ]Classic rubber band designs![/url]