Integrating a CMM Into an Engineering Technology Class Utilizing Simulation and Hardware

Abstract

While most would consider learning to program a coordinate measuring machine (CMM) to be a skill best learned in a one week tutorial format training class, the Purdue Polytechnic in Columbus has integrated these skills into a semester-long class that treats the CMM as a tool to satisfy a mechanical design objective. The class is titled "Inspection and Validation of Product Design" and features six projects throughout the semester along with various lessons on geometric dimensioning and tolerancing. Each of the projects requires the student to create an assigned solid model using a computer aided design (CAD) tool from a drawing. Each student then has the model manufactured using a three-dimensional rapid prototyping machine (3D printer). The CAD models are then imported into the CMM programming and simulation tool (Calypso) for the students to design their measurement plan. Since the Purdue Polytechnic in Columbus has only one actual CMM (Zeiss Duramax), it is a great advantage to have 25 copies of the simulation software. Students can develop their measurement plans and practice and perfect them using the simulation tool. When they feel their measurement plan is satisfactory, the students load their CAD model and measurement plan into the computer attached to the hardware as well as secure the actual 3D printed part onto the hardware. Carefully using the hardware controls, the students then execute their measurement plans to determine how closely the 3D printing manufacturing process matched the nominal drawing dimensions. Later in the semester, assignments are added that include GD&T measurements such as circularity, flatness, perpendicularity, parallelism, runout and position tolerances. Over the course of the semester, students learn about the design process, prototyping, inspection, and validation while using the CMM as a tool for those lessons. This work includes detailed descriptions of the projects, the reports required for each project and the objectives of each project. There are also analyses of the 3D printing process and comparisons to a machining process in several projects.