the speed controller ive been testing the robot out on is a dual one, which because of the motors using an earth( 4 volts--- which i tested using a multimetre) it only allows one motor to operate at a time,

i think if i was to get 2 seperate speed controllers like woody mentioned above i think that should work because they would be both using an earth but they would be on a seperate circuit does that seem like it would work???

but if not ill have to make the motor brackets out of poly