In the five-bar-link parallel link robot joints should be passive joints, which are free to rotate, having a closed-loop kinematic chain has notable features. : r/robotics
Alpha-Writer: A Computer-Controlled Letter Writing Robotic Arm | Servo Magazine
You've never seen the Robot Joint like this one! - YouTube
Robot Links and Joints - Robotics Bible - Projects, News, Videos, Books, Events, and more | Robotics Bible – Projects, News, Videos, Books, Events, and more