UGEARS Kóbor Grimbusz - mechanical model

The UGEARS Kóbor Grimbusz™ is a mechanical model of the enchanted Knight Bus from Harry Potter and the Prisoner of Azkaban. Assembled from 268 parts in about six hours, it is rated as a medium-difficulty build. Its movement comes entirely from a gear system that transfers energy from a spring to the wheels, and a special flip gear lets the bus roll freely. The finished model measures 19.6 x 6.5 x 15 cm.

The standout feature is the magic knob on the roof. Turning it counterclockwise narrows the bus so it can slip through traffic, and the bus slows down as it does so. Turning it clockwise restores the full width and, with it, the bus's high speed.

Sanding and waxing the moving parts helps the mechanism run smoothly; sandpaper and wax are included. The illustrated instructions are available in 11 languages. The model can also be painted purple, as seen in the film.