Place the finger conductors tree on each side. ( see on the picture where you need to place them; green dots).
Place the axle wheels of a lego car into the holes in the movable part.(5)
You can use some glue to make sure that they are fixed. When you have done this, you can install the lego wheels. Or you could 3D print them, if you don't have one. They are in attachment.
If you can't 3D print, than you need to take a piece of wood (10 mm thickness), and make a round wheel with diameter 10 mm.
Now the pattern maker component is ready.