If you have an interest in robotics, then a robot arm is a great educational tool to start your journey. But professional robot arms are expensive and the DIY route is more informative anyway. That’s especially true if you take the time to design the arm yourself, as did Oliver Paff after he got himself a 3D printer and used his newfound fabrication capability to create this affordable 3D-printable robot arm.

Paff’s goal wasn’t to build the best robot arm in history. His goal was to learn the basics of robotics, including mechanical design, CAD, 3D printing, electronic design, and programming. This robot arm was perfect for that goal. It doesn’t have a high payload capacity or very good repeatability, but it was cheap to assemble and gave Paff a platform for experimentation and learning.

This is a 6DOF robot arm that Paff designed himself in Onshape. Almost all of the structural and mechanical parts were 3D-printed on an inexpensive Creality Ender 3.

An Arduino UNO Rev3 board controls the servo motors that actuate the joints. Paff initially tried to drive those directly from the Arduino, but ran into a common issue: the Arduino’s pins cannot supply a lot of current. So Paff added a servo motor driver module, which solved that problem and gave the motors plenty of power. Paff also redesigned the gripper to be more versatile. And the code even incorporates inverse kinematics to make user control more intuitive.

In testing, this worked quite well and Paff has plans to continue improving the design over time and expand its capabilities. If you’re interested in constructing the current version, Paff was kind enough to upload his files.