This robotic arm is a follow-up work of my Master's Thesis, and is featured in detail in the following paper: https://arxiv.org/pdf/2104.04064.pdf
The arm itself has an elephant's trunk or snake like appearance, meaning that each joint can freely rotate in any x, z direction with an maximum angel of about +/- 40°.
You can watch the robot move here: https://bit.ly/2ZhLFUE
I'm also giving a short talk about it: https://bit.ly/3dctx6R
The movement of the arm is controlled by an Arduino Nano micro controller and three 35Kg servo motors in each joint. The Arduinos are connected over I2C and receive commands from an additional Arduino, that can be connected via USB to a computer. The arm is mostly printed in PLA, only the flexible gripper and the protective shell for the electronics are printed in TPU. In order to print the ball-joint mechanism, a precise printer with a tuned profile is needed. For the arm in the pictures an Anycubic I3 Mega was used.
Additional requirements are:
M3 screews: https://amzn.to/3jLye8Z
M3 nuts: https://amzn.to/3ahPv6z
M5 screews: https://amzn.to/3tUGdVS
M5 nuts: https://amzn.to/3dan9gh
powerfull power supply: https://amzn.to/3phFQRP
voltage converter: https://amzn.to/3jQuumz
Arduino Nano: https://amzn.to/3tVmx46
Servo Motors (35Kg 180 Degree + 25T arm): https://bit.ly/3pc4dQQ