Retrofitted vertical milling machine

• Main Authors: Chua, Elliott Edom, Co, Kendrick Brian, Cokee, Bernard Patrick, Guzman, Noel V., Pardo, Franklin
• Format: text
• Language: English
• Published: Animo Repository 2001
• Subjects: Milling-machines; Milling machinery
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/14588
• Institution: De La Salle University

The study presents a computer-controlled vertical milling machine entitled Retrofitted Vertical Milling Machine. In response to the need for an economical alternative to expensive CNC machines, the group had aimed to retrofit a manually operated vertical milling machine by implementing CNC technology. The retrofitting consisted of 3 parts: mechanical, electronic and software components. The mechanical aspect is composed of mounting plates to support the X, Y and Z motors which were linked to their respective axes by a coupling. Then for the electronic part, a closed-loop system was implemented. The circuit made was equipped with precision motor controllers which enabled the h-bridges to drive the motors. For the feedback, incremental shaft encoders coupled with line amplifiers were mounted on the motors shaft to obtain the actual position of the machines axes. In addition, the entire circuit communicates with the host computer via 2 parallel ports (LPT1 and LPT2). Finally, a software application was created to interface the machine tool with the host computer. The program was designed with a G-code editor, a graphical simulation window, and control buttons. To ensure the retrofitted machine would be accurate and reliable, statistical quality control was applied. Data were gathered from samples of wood and brass drilled and milled by the retrofitted machine. Subsequently, controlled charts were generated from the experiments. After analyzing the control charts, the group has concluded that the accuracy of the retrofitted machine is ±0.1 mm. After the machine had been retrofitted, it was able to perform drilling and milling operations of different shapes from lines to curves. Statistical results gathered in the experiments indicate an accuracy of ±0.1 mm.