Geometric Dimensioning and Tolerancing (GD&T) Integration throughout a Manufacturing Engineering Curriculum

Abstract

, as a graduate student, he taught quality and applied statistics and researched machining models for monitoring and control. At Cal Poly, Dr. Waldorf has taught and developed courses in manufacturing process design, computer-aided manufacturing, tool engineering, quality engineering, and reliability. He has participated in numerous activities related to the improvement of teaching methods, teaching assessment, and curriculum design. He is currently the faculty advisor for Society of Manufacturing Engineers (SME). His research interests are in metal cutting process modeling, tool wear, cutting tool design, and engineering education. Currently Trian teaches courses for the IME department in computer-aided-design (CAD), manual machining processes, fixture design, computer-aided-manufacturing (CAM) and computer-numerical-control (CNC) machining. AbstractThe Geometric Dimensioning and Tolerancing (GD&T) ASME Y14.5 standard 1 for specifying engineering requirements on drawings and related documentation was initially accepted in 1994 and has been formally modified as recently as 2009. Despite many advantages for clarifying and simplifying design requirements as well as implications for reducing manufacturing costs and streamlining manufacturing activities, the various aspects of the standard have seen inconsistent adoption throughout the manufacturing industries across the US. A recent increase in employer expectations when hiring undergraduates at one institution has prompted an ambitious effort to increase student learning of GD&T standards and of the numerous practical ways to utilize it to achieve high quality, low cost manufacturing. The effort involves integrating different aspects of the standard across a broad spectrum of the curriculum for both an undergraduate major program in manufacturing engineering and for a manufacturing engineering concentration in a mechanical engineering program. Lecture content, assignments, lab exercises, and projects have been developed across eight different courses to increase understanding of GD&T from various perspectives such as documentation, mechanical design, design for assembly, design for manufacture, fixture design, machining, and inspection. Altogether, the content covers most of the key GD&T concepts and provides a consistent, coherent approach to graduating GD&T-savvy manufacturing and mechanical engineers. A comprehensive exam has been compiled to track student learning and to monitor the effectiveness of new efforts in this key area.

Teaching Geometric Dimensioning and Tolerancing Concepts Using 3-D Computer Models and 3-D Printed Parts

“…GD&T provides an effective means of specifying nominal part geometry and the allowable variation. The importance of GD&T includes: producing components that are interchangeable, allows designers to more clearly communicate functional relationships between features in drawings, and reduces costs by decreasing waste [4][5][6][7][8][9]. However, GD&T concepts can be difficult for students to understand not only because of the many symbols and terminology implemented by this graphical language but also because it may be difficult to comprehend the 3D nature of geometric tolerance zones.…”

Students’ Understanding of Datum Reference Frame Concepts in a GD&T Course: Student Outcomes Across Multiple Semesters

“…To be successful, DRF concepts need to be introduced and applied in many ways and at different levels of complexity. Waldorf and Georgeou discuss integrating GD&T concepts throughout a manufacturing curriculum by designing assessments at different cognitive levels of Bloom's taxonomy [3]. They specifically mention the importance of designing assignments where students must exercise cognitive processes in application, analysis, synthesis, and evaluation.…”

Evaluating Concepts Presented in a Geometric Dimensioning and Tolerancing Course

“…More recently we have seen an increase in GD&T publications related to engineering education and product definition [5], [6], [7], [8], [9]. These articles make an effort to reduce some of the misconceptions involved with GD&T.…”