SO-ARM101 "Arm Servo Motor Kit" is an open-source dual robotic arm kit that works with Hugging Face's LeRobot robotics ...

According to this article on the project [Kachi Chan] used Cinema 4D to simulate the motion, ROS for control, PincherX150 robotic arms modified with Dynamixel XM 430 & XL430 servo motors ...

The usual go-to when building a simple robot arm is the ever-pervasive ... and adapted it for small stepper motors. First he tried printing out the servo version on thingiverse.