If you’ve ever wondered whether it’s possible to create a functional, high-torque gearbox entirely out of 3D-printed parts, this build might just pique your interest. In today’s project, we explore a fully 3D-printed gearbox designed to power a 3D-printed shredder, using minimal external hardware and some serious torque potential. Let’s break it down.
The Concept: Power Through Plastic
The idea is simple but ambitious — build a powerful shredder using a gearbox made entirely from plastic components, printed at home. The motor is anything but weak: a brushless DC motor typically found in RC drones or planes, delivering enough punch to require careful regulation.
Key Specs:
- Motor: Brushless DC, drone-grade
- Battery: Lithium Polymer (LiPo)
- Speed Control: Electronic Speed Controller (ESC)
- Gearing: Herringbone gears with ~81:1 reduction
Engineering the Gearbox
At the heart of the design are herringbone gears, which are shaped like interlocking triangles. These offer smoother operation compared to standard spur gears and help mitigate backlash.
Gear Ratio: 81:1
This means the small pinion gear spins 81 times to rotate the output gear once — allowing the system to trade speed for massive torque output.
However, there are tradeoffs. The gearbox is entirely plastic, and plastic-on-plastic friction can be a major heat source. That heat could, over time, deform or melt parts of the assembly.
Challenges and Limitations
The project is clearly labeled as temporary, and the creator candidly shares some honest flaws:
- Vibrations during operation nearly caused the entire structure to come apart.
- Friction between plastic gears is intense and could lead to overheating.
- The ESC setup is “janky,” requiring manual control via a remote receiver.
Despite the limitations, it's a great proof-of-concept, and there's already a plan in place to improve things, like integrating a potentiometer for smoother, more consistent control.
The Test Run
With safety goggles in place, the gearbox is powered on — slowly and cautiously — using the lowest motor setting. What happens next?
“brrrrrrrrrrr!”
That brief moment is where it all pays off — the torque buildup is impressive, even with the setup dialed down for safety.
Final Thoughts
While not built for long-term use, this project is a fantastic exploration of what’s possible with hobby-grade 3D printing and some creative engineering. It opens the door for functional mechanical builds made mostly from plastic and inspires future iterations with improved durability and control.
Want to see this gearbox in action?
👉 Watch the full video on YouTube