Comment by glouwbug

In all honesty I’d try and model a 2d 3-link arm in software with forward and inverse kinematics. Then I’d model the inertia of the bars, and model DC motors to apply a torque to the bar interconnects. I’d then model PID controllers for each motor to smoothly move the arm. I’d then move to 3D. Once the physics is modelled you’ll find speccing the motors, solidworks, motor drivers, and MCUs relatively straightforward if you have some basics in electronics.

The fundamentals of robotics is in the math; think control theory. Don’t over emphasize the surface level like ROS, arduinos, and Lego kits. Those are implementation details