Over generations, engineering faculty qualifications transitioned from practice to scientific theory basis, and engineering schools progressively shifted responsibility for instructing elements of practical design to industry. The result: a progressive erosion of practical design knowledge (design esoterica) in faculties and industry. Tolerancing based on ASME B4.2 Fits is one element of eroded mechanical engineering design esoterica and is now poorly understood in academe and industry. As a result, students and early-career mechanical design engineers are challenged to select appropriate Fit-types, and therefore to apply appropriate tolerances to their designs. Though unquantified, this leads to elevated industry costs associated with manufacturing and service.

With thirty years in mechanical engineering design, over twenty years in the application and instruction of geometric dimensioning and tolerancing (GD&T) in industry, and six years instructing GD&T at the University of Manitoba, the author of this study has observed a general absence of tolerancing knowledge in industrial and academic environs. Recognizing the challenges of learning and teaching mechanical design esoterica in general, and dimensional tolerancing in particular, the author proposes a collection of artifacts as a first step in reintroducing, into mechanical engineering design, a functional understanding of tolerances, and tolerance magnitudes. Three visio and visio-haptic artifacts are designed for use in developing a cognizance of the clearance Fit-classes and the micron-scale tolerances associated with them. The artifact designs are based in the mechanical engineering design experience of the researcher. A qualitative self-study accompanies the engineering design study of the artifacts. A rhetorical Voice of a Design Companion is invoked as anecdotalist to convey the researcher’s design thinking, and to explore the evolution thereof. The scope of the engineering design study is limited to ideation, concepting, and final design. Fabrication and evaluations of the artifacts are contemplated as future steps.