Super fast paper plane launcher

Step 5 Fitting of the pushbutton switch: a suggested option

You can attach the switch in several ways, but this is the way involving the optional washer and hole: First put the battery connector through the hole and then the switch. Screw the washer on the switch and fit it back in the hole. Attach the battery holder and fit the batteries. Push the button to check if it is working. Check the direction of rotation of the wheels. Of course, at the point where the two wheels meet, they should move away from the rest of the construction. If this is not the case, reverse both batteries. Stick the battery holder under the plywood board with some double-sided tape or glue.

The launcher is ready; all you need now is a paper plane. (next step)