Instead of sticking with the typical tabletop-scale builds, Arduino hobbyist and YouTuber UncleStem chose to take a familiar robotics concept and push it into much larger territory. 

After completing a custom Arduino Uno board that was scaled up seven times its usual size, he set out to find a project that could properly test the oversized controller in a real-world application. He landed on a turtle-style obstacle-avoiding robot, a design known for its simplicity and reliability.

The original version relies on basic sensor input and straightforward movement logic, making it an ideal candidate for scaling. By increasing every component by a factor of seven, the project transforms a compact educational robot into a significantly larger machine while preserving the same fundamental behavior and control principles.

Custom motor shells help scale up design 

To handle the increased size and weight of the project, the build started with a shift in hardware strategy. Instead of relying on the small hobby motors typically used in basic Arduino turtle bots, UncleStem turned to motors salvaged from children’s ride-on toys. These 24-volt units deliver significantly more torque, making them suitable for driving a much larger chassis, TechEBlog writes.

Rather than simply mounting them as-is, he designed custom-fit shells that slide over the motors, maintaining a clean, unified look. This approach preserves the visual identity of the original compact robot while adapting it to a far more demanding mechanical scale. The result is a system that combines practical power with a carefully considered, scaled-up aesthetic.

Because of the size and precision required for the frame, the laser-cut components couldn’t be handled with standard workshop equipment. UncleStem opted to outsource the cutting process to a professional service equipped to work with large-format sheets. The parts were produced from a full-sized 1mm acrylic panel, ensuring clean edges and consistent accuracy across the oversized structure.

Ordinary workshop cutters would have struggled with both the scale and material constraints, making outsourcing the most reliable option for maintaining structural integrity and dimensional precision in the build.

At the base of the build, the wheels sourced from lawn equipment suppliers provide surprisingly smooth movement under the robot’s heavy frame. To maintain visual consistency, 3D-printed hubcaps were added, helping unify the oversized design.

Control is handled by a custom-built, enlarged Arduino Uno created by UncleStem, which conceals a standard Arduino Nano inside for actual computation and code execution. Even the wiring had to be improvised at scale, with metal rods used in place of traditional jumper wires, since no off-the-shelf equivalents exist for a project of this size.

The navigation logic follows the classic turtle-bot pattern without modification. The robot drives forward in a straight line until its front sensors detect an obstacle, triggering an immediate stop. It then performs a sweep by checking left, center, and right to evaluate available space, identifies the clearest path, and executes a turn in that direction before resuming forward motion. 

This simple decision loop repeats continuously, allowing the system to operate autonomously using only basic obstacle detection and directional comparison.