Automation of Rack Milling Machine

Abstract

Our project is about automation of old milling machine by replacing its control circuitry with
PLC logic. There is one old Germen rack milling machine in the power tools manufacturing
industry named Eibenstock Positron Ltd. Tardal for making the racks of metal bar. This
machine was working on old hard wired control logic. This control logic had difficulties in
troubleshooting problems, modification of system could not be done easily and control box
was large, also complicated. In that machine, we replaced hard wire control logic by PLC
based control logic. The mechanical components remained same but we used new electrical
components to make compatible with PLC. The ‘Eibenstock Positron’ is power tools
manufacturing industry; there, different types of machines are assembled. These machines
include drilling, screwing, mixing, cutting etc. In magnetic drill machines, for vertical
movement of drill head, instead of smooth slider, racked slider is used. Rack slider helps not
only for momentary action but also stays in steady position while operating against vibrations
created by the drilling action.
Keywords: PLC, relay, reed switch, 3-phase motor, SMPS, proximity sensor, contactors