For a first robotics project, this is a bold one to take on: a six-axis arm with a rotating base, shoulder, elbow, wrist articulation and a two-finger gripper, all in printed red parts, sitting on a matching red enclosure that houses the electronics. What stands out most to me is the control side. The maker wrote an HTML page that talks to an Arduino UNO over USB serial, with JavaScript reading and writing the connection, and the page runs in Chrome or Edge. Using a plain browser as the control panel for a printed arm is a neat setup.
The electronics list is refreshingly modest: four MG996R servos and three MG90s, with the UNO driving seven servo pins, 3, 4, 5, 6, 9, 10 and 11, at 9600 baud. The software details show real care. Every servo parks at 90 degrees and is attached one by one at that angle, the shoulder runs a mirrored pair on pins 4 and 5 with the second angle computed as 180 minus the first, and every incoming target is constrained to per-joint limits such as base 0-180, shoulder 15-165, elbow 10-170 and gripper 20-120 degrees. Stepping each servo one degree per cycle with a 15 millisecond delay seems to me a sensible way to get smooth motion, and the sketch ignores any incoming line that does not hold six values.
The results back it up: the arm runs automated sequences, rotating its base, extending forward, opening and closing the gripper and swinging upwards and backwards, all driven from a page with sliders, a home button that parks every joint and a save feature for poses.
One open area is the mechanical side. How the link lengths and dynamic load capacity were worked out is not explained, and the servo attachment method is not described beyond the maker saying models are available.