Motorized excavator that uses one L-motor and gearbox to control 4 functions - 3 to move arm with bucket and 4th for rotation. The 3d file was done in stud.io and the whole build is stepped. LDR file is inside the .io file if needed. The whole build is stepped so you don't have to study the model, just hide everything and unhide part by part. Grouped parts are meant to be build outside of the main structure and added to it as a whole. The motor is not present in the stud.io at the moment of build so it is brick-build.