Students' familiarization to methodical troubleshooting through a capstone project

Abstract

This paper explains the technical training and methodical troubleshooting methods acquired through the entirety of the Outcome Based Education approach to Electrical Engineering Technology coursework promoted at Purdue Northwest. Many engineering students are focused mainly on theoretical coursework with some structured laboratory experiments. However, troubleshooting of equipment and complex machines are not given sufficient attention for a typical industrial setting during regular engineering coursework. Purdue University Northwest's Outcome Based Education allows students to gain hands-on experience troubleshooting complex circuits, machines, and their subsystems. In order to familiarize students with troubleshooting and identifying equipment failures, the resurrection of a relatively complex and non-functional NovaMill 3-Axis CNC Milling Machine is selected as a Capstone Senior Design project. The objectives of this project include identifying the different sub-systems of the machine, isolating each sub-system, testing and documentation of initial status, identification of failed sub-systems, repair the failed sub-system, integrate the overall machine, and perform final testing on the completed machine. A procedure will be developed to teach future students similar methodology to identify the failed components of a complex machine and finding solutions to fix it. The NovaMill 3-Axis CNC Milling Machine explored in this paper is a complex machine comprised of Stepper Motors for each of the three degrees of movement, GeckoDrive Stepper Motor Drivers, a multiple-output voltage AC Power Isolation Transformer, twin AC-DC Voltage Rectifiers, an Automatic Tool Changer, and a high-torque Spindle Motor along with peripheral electrical components such as fused terminal blocks and control relays. The original Novamill was controlled by an obsolete and proprietary PC-based control system, while the newly repaired and retrofitted machine explored in this paper was modified with a Linux-based control system running on a BeagleBone Black Microcontroller with a communication link for interfacing. Implementation of the BeagleBone Microcontroller was developed to allow remote communication link over Ethernet or direct control with keyboard, mouse, and local display. Understanding and repairing of such a machine requires a holistic understanding of each sub-system and the ways each of the systems interact.