Cut out using pieces using color mapping on your laser. The gears work using .125 wood but are much better when using .125 acrylic. Assemble the book case by attaching the rails into the slots. The extra layers on the left side of the book keep the gears from coming loose when the box is closed. The right side inserts should be stacked so that the smaller gears are on the bottom layer and the larger gears are on the top. Lastly, and this is most IMPORTANT!!!... Have fun!