Robotic arms for laboratory, personal or hobby use, namely, a robotic arm with changeable tool heads that can 3D print with filament and resin, undertake computer numerical control (CNC) milling, carve, create printed circuit boards (PCBs), laser cut and engrave, glue, paste, fasten screws, write and plot, draw, paint, pickup objects, place objects, assemble objects, measure and dispense precise volumes of liquids, use sensors to map the workspace and determine the contours and slope for auto...