I don&#x27;t think you need all that. They use stepper motors so they do indeed turn exactly 90 degrees. What they <i>would</i> have to worry about is the suction cup not sticking perfectly. E.g. after a 90 degree turn if the momentum makes that part of the cube slide a little when they try to stop, it will introduce a small error. Maybe turning other parts of the cube would correct it.