Articulated Robots
Articulated robots are the classic six axis arms you see in automotive and metal plants. Their rotating joints give them a large, flexible work envelope, so they handle machine tending, material handling, dispensing, and painting. When you shop, match payload and reach to your heaviest part plus the gripper, and check repeatability for precision work. Used articulated arms from major brands are widely available and often a strong value, but confirm the controller generation, spare parts availability, and whether the unit has been rebuilt or just cleaned up.