The functioning of this mechanism is really easy and intuitive. After following the tutorial step by step take your time and enjoy the result of your work. As we said we will use two different colours buttons:

- A blue button to start the rotation

- A red button to invert the rotation's direction

So, push the blue button and keep it pressed to start the rotation, if you want to stop the rotation just release it. Now push the red button one time to invert the direction and after you've done that, push the blue botton and keep it pressed to run the engine.

You can alternate the rotation from clockwise to counterclockwise with a click.

While you are pressing the blu button you can smoothly increase or decrease the speed of the spinning turning the potentiometer's handle to the left or to the right.

When you release the potentiometer's handle, the speed will be constant in both sense until you release the blue button.