Re: [mowbot] Locomotion (was: Hello, and lots of ideas)

robin nospam at
Mon, 23 Sep 1996 20:13:21 +0100

On Mon, 23 Sep 1996 07:36:39 -0400 (EDT) Thomas A Maier
<tmaier+ nospam at> wrote:
> For example, running on even moderately uneven ground will
> probably require
> some relatively sophisocated suspension to make sure that the drive and
> steering
> wheel are always in contact with the ground.

Aargh. More strange word-wrap! Please tell me I'm not alone seeing

I seem to remember there was a complicated suspension arrangement
underneath the Husquvana mower. I hope we can come up with something
better. Tracks would avoid the problem, but have problems of their
own, being prone to getting gummed up. I am still inclined to
carry on the successful scheme I have used on the table-top: two
drive wheels (D) with their axes on a diameter of a circular outline, and
a third wheel on a swivel for support. On a smooth surface, this doesn't
even have to be a wheel, just a rounded foot is adequate.
.- S -.
/ c \
| D D |
\ /
As there are only three points of contact with the ground, it is
impossible for any wheel to be lifted clear (assuming all other parts
of the underside of the mowbot have sufficient clearance). The main
problem with this design is ensuring that the centre of gravity is
sufficiently low and near the centre of the triangle of the wheels (c)
to prevent the whole thing toppling over when it start or stops suddenly.
Putting another support wheel at the back runs the risk of lifting one
of the drive wheels off the ground.

Indulging my fantasies, I would really like a legged robot, but I
think that is still a bit beyond the limits of technology we should
try to adopt. Maybe in Son of Mowbot:-)


R.M.O'Leary <robin nospam at> +44 973 310035  P.O. Box 20, Swansea SA2 8YB, U.K.