Building a Robot Arm From Scratch, But Doing it Right
Mirza's first robot arm disappointed him. So, he went back to the drawing board and built a better robot arm from scratch.
Back in 2024, Mirza built his own robot arm from scratch. It was similar to what many people build when they first start out: a shaky, 3D-printed affair actuated by small hobby servos and controlled by sliders in a Python app running on a PC. I think that’s perfectly respectable for a first attempt. Even more respectable is the fact that Mirza gave it another try after learning some valuable lessons.
That quality is what actually separates the amateurs and the pros. Mirza was able to identify the mistakes he made and the shortcomings of his first design. He then dedicated himself to starting over from scratch in order to incorporate what he learned and build something better.
The basic concept is still the same. This is still a servo-actuated, 3D-printed robot arm. But it is better in every way, starting with the servos. Those are now MG996R servos for the bigger joints and MF90 servos for the wrist and gripper. Those alone make a big difference, as they’re more accurate and move more smoothly, without straining under the modest weight.
Helping to smooth the movement are an ESP32 development board and a PCA9685 12-bit PWM servo driver module. Good control makes a world of difference when it comes to the jitters in a robot arm.
From there, Mirza put a lot of effort into the mechanical design. Instead of slapping components on wherever they would fit, he spent the time in CAD to get a clean design. He even considered wire management, which is a real pro move. The servos still act directly as the joints, which isn’t ideal, but these servos are beefy enough to handle the load.
Finally, on the control side, Mirza abandoned the PC entirely. Using a Nextion touchscreen display paired with its own ESP32 dev board, the controller communicates directly with the robot via ESP-NOW. There are still sliders for adjusting the joint angles, but the robot is now much more usable. Mirza even added a graphic of the arm, labeled to illustrate the joint that each slider moves.
This new robot arm is leaps and bounds ahead of the original. And at this rate of progression, we can’t wait to see what Mirza’s next robot can do.