We’ve seen a number of small-scale engines shared by JohnnyQ90 on YouTube, but this one is different. That’s because there’s an honest-to-goodness three-speed manual gearbox attached to the back, and we want it.
This setup uses three forward speeds as well as a reverse gear, operated through friction clutches. It’s all contained in an aluminum housing that’s 3D printed, and gear changes are done through two connections on the top of the gearbox. The lever closest to the engine selects forward, neutral, or reverse, while the other lever goes through first, second, and third. They are operated by two servos; a third servo controls the engine’s throttle.
Toggle switches on the controller operate the transmission, with throttle input managed by a squeeze trigger. The setup is demonstrated on a simple base where the engine and transmission are connected to a spinning weight, which places just enough drag on the powertrain to hear the revs climb through the gears and different rates. It all seems to function well, even handling full-throttle gear changes without any apparent issues. Whether that’s the case after five years or 60,000 miles, however, remains to be seen.
As with other JohnnyQ90 videos, the attention to detail in the construction of these small mills is astounding. The clip opens with the creation of a smaller pulley to get more pressure from the water pump, and side panels on the oil pan are replaced with glass so we can see the crankshaft in action. And the sound isn’t bad, either.
The video description includes a link to buy the three-speed stick, showing a price tag of $439.99. It’s also offered as a bundle with the engine (a 17.5-cc four-cylinder) for a cost of $1,291.97. All we need is a 1:8 scale Honda S2000, and our radio-controlled dreams would be complete.