Simple relay function with 2 buttons and continuous signal
I think what you are describing requires a motor start stop circuit. The only thing you have to figure next is what to do once the motor stops. With the circuit above it just does nothing because the motor rotor is positioned to press the stop button. It can be arranged to allow the start button to restart the motor and, with some extra engineering pressing the start could reverse the motor back to the beginning. You need to pay attention to precisely what you expect to happen in all stable and transient states. Nobody can tell you what to do, you have to decide but, regarding your original question, this is, I believe an answer.