Doyusha Self-Propelled Propeller Cart, Leonardo da Vinci Series

Pre-painted assembly kit. Although this is a rough sketch, Leonardo's self-propelled cart is clearly comprised of a complex structure. In addition to two counter-rotating cogwheels and a spiral spring, the kit also includes a mechanism resembling a watch escapement to prevent the spring from retracting suddenly when starting off, and even a small, but functional brake for winding the spring. Product dimensions: 158mm wide, 85mm high, 160mm deep.

(From Amazon.co.jp) Plastic model requiring assembly and painting. Tools, paint, etc. may be purchased separately.