If we use 4wheels;two driven and two caser wheels and put the two casters
on a pivioting axel we can get the stability of a 4 wheel system with the
ground hugging ability of the three wheel system.
Crude diagram follows:
caster drive
Wheel wheel
____ /\ __________
o|____| |__________|
f || \/
r || -----------------------------------
o || | |
n || | |
t || | |
_ || | |
/| || | |
( ||==| Front axel pivot |
_| || | |
|| | |
a || | |
x || | |
e || | |
l || -----------------------------------
|| ____ /\ __________
o|____| |__________|
\/
caster drive
wheel wheel
These stupid text digrams take forever to draw :-(.
Ron