I have built an enormous and heavy Lego RC tank, driven by 2 XL Motors, connected to a subtractor, one motor is for steering, the other is for propulsion. Despite having already geared down the motors to provide more torque for the vehicle, the sheer weight of the machine is too much for a single XL motor, even geared down, so the gears tend to grind a bit, but I do not want to gear the motors down any more since the vehicle already travels incredibly slowly. I am wondering if combining two XL motors for propulsion and steering (resulting in 4 XL motors in total) will give me more torque whilst retaining the same RPM.



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    This question likely already has answers in the form of bricks.stackexchange.com/questions/8867/… and bricks.stackexchange.com/questions/1327/…, even though those questions have slightly different scope. – Phil B. Dec 22 '17 at 1:47
  • Maybe you could provide some pictures. Then we may help in your particular build. At the moment, the question is rather generic and a possible duplicate of other questions. – Aziraphale Dec 22 '17 at 10:12
  • The XL motor is already pretty powerful so you do have to consider the ultimate strength of any plastic gears involved in the drive train particularly when it is well geared down. Using two motors will tend to compound the gear strength issue. As others have said some pictures of your tank and its drive system would be very helpful. – Quorneng Dec 24 '17 at 14:36