In order to avoid furrows, you should press the detail out from the side, where pattern of lines is thicker. We recommend to check all elements, especially gears, for the absence of burrs on the teeth. To safely release a part from the board and avoid any potential damage to it, gently press your fingers about the indicated lines. For the best assembly results and to ensure the correct fit we recommend checking each detail for flaws and removing imperfections using the finest grit sandpaper. If connecting of certain parts appears difficult, try using household wax candle to lubricate the parts.