I´m sharing with you my robotic arm "Ramos MK-III", a version I made for academic purposes, based in the AR2 robot.
I had 1 month to develop a robot arm, so I took stepper motors that I had at my hand. I made my own design based on the AR2 but according to the stepper motors I had, also using pulleys and timing belts instead of planetary gearboxes.
This version is not as accurate as the AR2 is, but stills functional and is way cheaper.
Here you can see the MK-III moving:
Thank you for your time! Greetings!