An Overengineered Pencil Sharpener That Reciprocates Its Blade and Slowly Rotates the Pencil

A hand-cranked pencil sharpener moves a blade back and forth along curved tracks while advancing and rotating the pencil in small steps. Chronova Engineering devised an intermittent gear mechanism to make the pencil turn while producing a concave tip.

The mechanism works, but sharpening is slow and labor-intensive rather than practical.