> looks great! The only point where it looked a bit jerky was when
> driving up the stairs. With the steering / braking system, do you
> mean you set the position / forces of the front wheels and the car
> follows it based on friction with the ground?

   Thanks to Koppi addition of definable keyboard shortcuts, I was able
to assign a key for acceleration, another for braking, and two more for
the steering to left and right:

   + the acceleration key just applies some angular speed to the tires,
which rotate freely around a hinge constraint. Using high friction on
the wheels and the ground, the car starts rolling...

   + the braking key cuts the power and also blocks the free rotation of
the wheels hinge. Again, friction does it's work and the cars stops
reasonably well.

   + the left/right keys turn on the motors of a pair of hinge
constraints attached to the wheels, on the appropriate direction. I
didn't need to implement any sort of differential... still don't know
why, but the car acts as if there is one. For the rest, I totally
disregarded any other things like caster, camber, toe, ackerman, etc...

   Apart from that, there is a simplistic suspension joining the steering
hinges with the chassis: this is where most of the failed attempts were
wasted, trying to find a combination that worked well and didn't break
under the forces involved.

   Oh, ...and the jerky moment at the stairs was me pressing left/right
to find a better attack point, as the power was not enough for a frontal
approach... :)

--
jaime

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