Weekend build–UGEARS model of the crazy Knight Bus from Harry Potter and the Prisoner of Azkaban

UGEARS is the Ukrainian company that creates spectacularly engineered models, reflecting the history of science and technology in plywood gears and rods. They also make steampunk and fantasy creations. Last year I reviewed several STEM kits provided by UGEARS (check out my reviews here) as well as a magnificent mechanical winged dragon model (reviewed here and still flying). This winter UGEARS added working, functional vehicles from the Harry Potter franchise (see my review of the Weasley flying car from Harry Potter and the Chamber of Secrets here).

I just finished the model of another kit from the Harry Potter series–check out my review below of the fun triple decker Knight Bus from the best of all the Harry Potter movies, Harry Potter and the Prisoner of Azkaban.

This is the bus that expanded and contracted around traffic, with the fabulous Life on Mars actor Lee Ingleby as the bus conductor.

Let’s dig into this kit!

First, here’s the scene from the movie featuring the Knight Bus:

The compact box ships from Ukraine or your local model shop.

It includes four sturdy laser-cut plywood sheets, one piece of wax and one piece of sandpaper–both for friction reduction, a large metal spring to run the bus’s wind-up-and-go feature, two rubber tires, and the instruction booklet.

Once built, the kit is a solid model for your shelf, which can be wound-up to speed across the floor. When completed my build resulted in a model with tight fitting parts, sturdier than my past experience with this series of kits.

The fitting tool, sandpaper, wax, wheels, and spring.

The bus runs courtesy of a spring-powered motor, which is wound using a “secret” removable key stored on top of the bus. Raise the manipulator rod, also on the roof of the bus, to lock the drive gears. With the bus stopped you can remove the secret winding key, insert it into the ratchet mechanism on the side of the bus and give it a few twists. To set the bus in motion, press down the rod wheel while holding the bus, and the bus is off. It all operates from a system of gears that transfer energy from the spring to the wheels, including a “flip” gear that lets the bus continue coasting.

But the most clever feature is how the bus can contract and expand. While expanded the bus moves quicker, slower when in normal position.

The bus operates on several interconnected gears.

Proper fit of the spring is key, and testing parts as you build will help ensure everything works once assembled.

The instructions are primarily visual, using symbols instead of words. For this kit assembly was straightforward.

But the mechanisms are also complex, and require careful alignment:

It’s important not to force the vertical control assembly as everything relies on it.

Here is the interior of the bus, nearly completed:

The exterior has plywood siding similar to that of the Weasley car. It looks good once completed, with Potter-themed design elements throughout. And yes, you can paint it that bright purple color of the original. Here is the Knight Bus zipping along across the floor:

Taking your time, this is a kit I’d recommend building over a three-day weekend with an hour or two per day of effort.

Make sure the eight hinges that attach the walls to the bus seat perfectly for the expansion and contraction to work successfully. Otherwise they will fall out in later steps. These properly fitted pieces serve as proof that the kit up to that point has been built correctly.

Ultimately the Knight Bus looked just like the product box image once complete, and functioned as specified. It makes for a nice shelf kit for any fan of the Harry Potter movies, and especially this scene from Harry Potter and the Prisoner of Azkaban.

And don’t forget to check out the other UGEARS kits I’ve reviewed if you missed them: the 2-in-1 Arithmetic Kit (reviewed here), the Gearbox (reviewed here), the Random Generator (reviewed here), the Tachometer reviewed here), and the Variator (reviewed here). In addition to the other STEM kits we reviewed, UGEARS offers four other STEM kits you may want to try: a Differential gear, a Counter, a Pendulum, and a Curvimeter tool, and outside the STEM series are other engineering marvel kits like the Pneumatic Engine and Dynamometer, plus many stunning, elaborate, advanced kits like the Windstorm Dragon reviewed here. Take a look at all the available UGEARS models at the UGEARS website for more information.