Robo-Bobulons

Robo-Bobulons, a series of modular robots with moveable arms. Originally created by the Bobulons from the planet Bobulonia in the Bobdromeda galaxy, the Robo-Bobulons have set out among the stars to explore the universe and meet new people.
Currently there are 4 active models of Robo-Bobulons: The first is the EGGHEAD Mark-IV, a Robo-Bobulon with an oblong sphere for a head and 3 arms. The second is the box-looking one called Boxulon, it's 4 armed. The third Robo-Bobulon model is the Bobo-Robo-Borobulon, a cylindrical Robo-Bobulon. The fourth model is the triangular Robo-Bobulon called Triangle.

Anyway, there you have them, the Robo-Bobulons. There are 4 unique arm types, 4 bases, and 4 heads. The Blender file is included to finetune the joint tolerances (highlight the center vertex of the hole or plug and expand the selection with ctrl and +, then scale only along the x and y axes using the scale command then locking the z axis with shift and z)..