How to create this cool geared whiplash

These nifty gizmos use a set of gears to uncoil and recoil. Alex Fox shows how to make one with wood.

They can also be 3D printed. Below is the inspiration. Oskar's video mentions the Thinkfun Tail Spin, but that model is currently unavailable on many outlets following a lot of poor reviews.

Image: YouTube / Alex Fox