Crazy Pen A Model Airplane,1:16 scale model, and the most amazing thing is that the model is fully functional! To build this model, he spent a total of 6000 hours, making it over three years. All elements of the aircraft, ranging from housing and ending with cables, ropes, levers, - acting. Housing bend the wooden blanks, everything else is assembled with tweezers. That's where the need stamina and a steady hand.