When it comes to Formula 1 racing, weight and the speed of shift changes are two of the most important characteristics of a competitive car. A modern F1 car weighs a mere 660kg (about 1,455 pounds) — that’s significantly less than even ultra-compact road cars like the Smart Fortwo. With weight at such a premium, racing teams can’t afford to build cars with the kinds of heavy transmissions that you’d find in cars at your local dealership. Instead, they use extremely compact sequential transmissions that weigh very little and are controlled by computers for quick shifts. YouTuber Indeterminate Design was able to 3D print a fully-functional 1:1 scale model of a F1-style gearbox controlled by ESP32 development boards, and it is mesmerizing to watch.
An F1-style transmission is dramatically different than the kind of manual transmission you’d find in any production car made from the mid-1960s until just a few years ago. Your typical, everyday manual transmission has a single clutch that you disengage with the foot pedal to disconnect it from the engine. With the clutch disengaged, you can change to any gear (as long as your speed isn’t too high) and it will shift smoothly thanks to the synchros. Very little information about current F1 transmissions is made publicly available, but they are sequential dual-clutch transmissions. Like a motorcycle, you can only shift to either the next gear up or down, but setup this saves a lot of space and weight. The use of two clutches, which are computer-controlled, ensures quick shifts.
This model F1 gearbox replicates that functionality and is entirely 3D-printed, with the exception of the electronics and hardware like the bearings. The input comes from an electric motor rather than an engine like a real F1 car, but otherwise it is very similar. The dual-clutch shifting is done by a pair of ESP32 boards, which were chosen because they had the performance to handle the incredibly quick shifts. Those control the stepper motors that disengage the clutches and move the forks. As you can see, the entire transmission is about the size of a four-slice toaster, which just goes to show why these are used in F1 cars. Indeterminate Design even built a throttle pedal and a steering wheel for control the throttle and gear changes. Of course, there is no actual car to steer, but the steering wheel contains the shift buttons and readouts for the electric motor “engine” speed and current gear. If you’ve ever wondered how F1 transmissions work, this is incredibly helpful.