In 2020, with extra time on my hands due to COVID lockdowns, I wanted to challenge myself by designing a robotic arm unlike anything conventional. I set out to create a fully 3D-printed robotic system that required only electrical components to function. The idea was to build a modular, adaptable arm with swappable claw attachments, making it more versatile than traditional fixed-function robotic arms.
To push the limits of small-scale robotic arms, I incorporated high power-dense servos that provided a strong balance of strength and smooth programmable motion. The arm featured independent joint articulation and an attachment mount that could rotate separately from the rest of the structure, improving control over tools and objects.
Unlike simple conventional robotic arms that are limited to a single function, this design allowed for automatic tool switching. The arm could swap attachments without any human input, enabling seamless transitions between different tasks. Attachments I designed included multiple claw variations for different grip sizes, as well as a screwdriver attachment capable of driving screws.
Because the arm could switch tools on its own, it was capable of completing multiple processes within a single program, without requiring a technician to intervene. This increased efficiency and expanded the range of potential applications, making it suitable for tasks that traditionally required multiple robotic systems.
One of the most unique aspects of this arm was the way attachments were engaged. Instead of placing motors or actuators inside the attachments themselves, the attachment motor was located at the back of the holding mechanism. This allowed the arm to open and close claws or push a screwdriver into a screw without requiring electronics in each attachment. This simplified the design, reduced weight, and improved reliability.
A key feature of the attachment system was its ability to rotate independently of the main arm. This gave the robot precise control over its tools, allowing it to manipulate objects or drive screws without moving the entire arm.
While the mechanical design was solid, the software side posed challenges. My limited experience with C++ and inverse kinematics prevented the arm from reaching its full potential. Future improvements would involve refining control algorithms to improve precision and reliability. Additionally, incorporating acceleration and deceleration controls would make movements smoother, reducing strain on the servos and improving overall efficiency. Enhancing path planning and refining attachment-swapping sequences would also allow for more seamless automation.
Another major step forward would be designing additional attachments to increase the arm’s functionality. Expanding beyond claw and screwdriver attachments to include specialized tools would make the arm more versatile. Additionally, creating a permanent stand with a built-in work surface would improve usability. A properly designed base would allow for easier material handling, better positioning of workpieces in front of the arm, and more efficient tool switching, making the system more practical for real-world applications."
Partially Built Arm With Screwdriver Attachment
Wooden Base for Arm
Base Being Created on DIY CNC Router