Woodpecker

It is a gravity toy. Blue slider and body of the woodpecker are connected by a leaf spring that makes the body oscillate and the slider jerkily move down. Gravity, elastic and friction forces cause the motion. There is a small gap between the slider and the post. Pay attention not to let the yellow beak touch the post. If not, no more oscillation and the woodpecker stops moving down. The video was made based on: It is possible to use helical spring instead of leaf spring: Inventor files of this video: