Hi. I've been working on a project of angle stabilization for a vehicle moving along a string, looking like this: The propulsion system is connected to the central wheel, while the outer two wheels are used for support. I've observed that during acceleration the vehicle rotates. I would estimate that this angle is proportional to the translational acceleration, and I need a way to quantify (or refute) my estimate. My model is following: τ - torque force generated by the propulsion a - translational acceleration (αr = a) r - radius of the driving wheel F1, F2 - tangenial forces of chasis torque due to motor torque Fw1, Fw2 - forces by which the wire opposes the deformation that the chasis torque would cause θ' - angle velocity of the driving wheel Is it correct to say that the following equation holds: I*θ'' = τ - r*m*a where I is the inertial moment of the chasis, and θ'' angle acceleration? How to I model the tangenial forces of torque acting on the end-points of my chasis and the forces of deformation opposition exhibited by the wire? I presume if it were a perfect, unbendable wire, it would be true that: F1 = -Fw1 and F2 = -Fw2 and no chasis rotation would be possible. In my case, as in any real case of object hanging on a wire, this is not true. Thank you all :) Ana P.S. This is my first dabble in anything rotational, so excuse my ignorance. This is how far I can get by using brain+Google.