I had a thought that's been puzzling me this whole morning, its more related to classical mechanics, however I am dealing with motors so... I thought it would be appropriate to post the question here. Lets say we have to identical motors(with identical gears) placed vertically on a table. Those motors are free to move, they aren't fixed. We placed the gears together so that when rotating the first gear the second will rotate etc... and now, we turned on the motors. Since their torques are in opposition and equal in magnitude they cancel out, the gears will be at rest. Now I can't imagine what is the result to the motors themselves, will they fall? Will they just stay there at rest? Is there any form of linear force acting on the motors(Aside from gravity)? Since the motor is placed on the ##y##-axis and gravity acts on that same axis, could there be a linear force acting on the motors on the ##x## ,##z## axis? Remember, the motors are free to move they are not fixed in any way to the table, and they are vertically placed.