Special purpose automatic slot milling machine for commutators, are offered by swetha automation technology. The machine is designed to select either mica under cutting or slot milling on the cupper segment. This machine is applicable for any number of segments. Optical sensor is included to sense the mica/copper and stops exactly at the slitting position. Indexing is operated with pre-programmed stepper motor and controlled by a programmable logic controller. All the moving elements are handled by pneumatic system. Feed is by hydro-pneumatic cylinder. The machine has the stipulynous to accommodate either individual commutator or assembled armature for slotting operation.