Effects of introducing a parametric Cad in a first year course in engineering degree regarding quality of technical drawings

Abstract

The evolution of teaching in technical drawing during the last years has been addressed towards new paradigms based on 3D modeling. Nevertheless, not only 3D modeling skills are important for an engineer, but the ability to generate quality technical drawings also are part of the learning objectives and should, therefore, be included in the curriculum. For several years, the core subject of technical drawing at Universitat Jaume I has been a common subject during the first course of different Engineering bachelor’s degrees (Mechanical, Industrial Technologies, Electrical, Chemical, and Agrifood/Rural). However, in the last two years, the subject in the case of Agrifood Engineering has been taught independently. This course, aiming for a more intuitive introduction to 3D modeling, the subject has experienced a general methodological change for all the degrees, except for the Agrifood Engineering one. Apart from changing the order of contents with the intention of improving spatial vision, the use of a different commercial CAD software was implemented, this being parametric.

In a previous work, the effect of this general methodological change was assessed through the academic performance regarding 3D modeling by comparing the scores before and after implementing the change, as well as through specific questionnaires addressed to students and teachers, obtaining very positive results. Notwithstanding, the effects of the change performed on the obtainment of technical drawings were not analyzed. Taking advantage of having two groups (the one that has experienced the change and the one that did not), they were asked to model and generate the drawing of the same parts in their final exams, with the aim of comparing the scores obtained when assessing their skills of modeling, but also in creating technical drawings (views, sections and dimensioning) and in the quality on technical drawings presentation (title block, line thickness, etc.). Scores were collected and statistical analyses were performed, bringing to light that despite the good results that were obtained in previous studies regarding the 3D modeling, teaching efforts in how to generate technical drawings with quality should be reinforced in future.