Manual Transmission System
I designed and built a functional manual transmission model to better understand the internal mechanics of automotive gear systems. The project features two gears, a synchronizer assembly, and a powered input motor, simulating the shifting process found in real vehicles. The main challenges throughout the design phase were tight space constraints and fine tolerances, which required precise alignment of the gears, shafts, and shifter mechanisms to ensure smooth engagement.
To overcome these challenges, I relied on rapid prototyping with PLA 3D-printed parts to quickly test component fits and motion ranges. Each prototype iteration focused on refining clearances between the gears, synchronizer hub, and shift forks, which was critical for maintaining proper disengagement until a gear was selected. The synchronizer design required especially close attention to geometry so the dog teeth could mesh smoothly under rotation without excessive backlash or friction.
Transmission is on the left, rotary engine on the right
Most components were 3D printed to allow for quick iteration and detailed customization, but areas that experienced higher loads, such as the shafts and couplers, were fabricated using manual machining techniques like lathing and welding. This combination of additive and subtractive manufacturing allowed me to balance precision, durability, and accessibility, ensuring that critical parts could handle torque transfer while still being easy to adjust and replace during testing.
The final assembly included dozens of interconnected parts, all of which needed to operate in tight coordination. Achieving proper gear disengagement before synchronizer engagement required precise spacing and alignment, and I iteratively tuned these tolerances until the mechanism operated smoothly at full rotation.
This project significantly deepened my understanding of automotive drivetrains and mechanical synchronization. What began as curiosity about how cars shift gears evolved into one of my favorite projects, one that combined design reasoning, prototyping, and mechanical intuition to bring a complex system to life.
Video of Model Working