I have a 298:1 Micro Metal Gearmotor HPCB 6V with Extended Motor Shaft
I’m planning to build a robot with two driving wheels with those pololu motors and two castor wheels.
The robot will have roughly 0.6kg. The motor shaft can sustain the weight of the robot in this configuration, if the wheels are mounted directly on the motors as in this picture?
All the best!
Those gearmotors should generally be fine in the kind of setup you are describing. Our micro metal gearmotors are often used in mini-sumo robots which usually weigh about 500g and have similar setups.