Modifying an Assembly Project to Improve Student Dimensioning Skills

• Published in: Association for Engineering Education - Engineering Library Division Papers p. 24.913.1
• Main Authors: Veurink, Norma L, Hein, Gretchen L
• Format: Conference Proceeding
• Language: English
• Published: Atlanta American Society for Engineering Education-ASEE 15.06.2014
• Subjects: Assemblies; Assembly; Balances (scales); Calipers; Colleges & universities; Engineering drawings; Engineering education; Sketches; Skills; Solid modeling; Solid modelling; Students; Three dimensional models

Modifying an Assembly Project to Improve Student Dimensioning SkillsMany first year graphics courses introduce students to solid modeling and technical graphics. At---University, all engineering students take a two to three semester sequence of introductoryengineering courses. The last course in the sequence, ENG1102: Engineering Modeling andDesign, focuses on solid modeling (3-D CAD), graphical communication, and computerprogramming. The solid modeling portion of the class exposes the students to sketch-based andfeature-based solid modeling and creating engineering drawings and assemblies. The graphicalcommunication portion of the course includes dimensioning, section views, and view selection.To give the students practice in creating CAD assemblies using parts they modeled themselves,student teams complete a project where they either dissect a simple object or design an objectusing simple components such as PVC pipe. Students are given the components of the assemblyand calipers to measure them during at least two class periods and are allowed to collectadditional measurements at various times outside of class time. The students are required tosubmit fully dimensioned engineering drawings of each component in the assembly andengineering drawings of the assembly.In the fall of 2012, the assembly project was modified in one section of ENG1102 in an effort toimprove students’ dimensioning skills. In this experimental section, the students were given aspring scale to dissect, measure, and sketch and dimension by hand in a single 80-minute classperiod. The students were then to create solid models of the components from their sketches,and if necessary dimensions were missing from their initial sketches, they were required tosubmit a formal request to the instructor to obtain the missing dimension(s). In two controlsections of the course, the students were given the same spring scales to model and takenecessary measurements from in two 80-minute class periods and were allowed access to thescales outside of class. Individuals from each student team in both the control and experimentalsections were to submit fully dimensioned engineering drawings of two components of thespring scale. In order to assess if the change in the project did improve students’ dimensioningskills, the drawings from the experimental and control groups were compared to determine ifdrawings from the experimental group had fewer missing and/or duplicate dimensions thandrawings from the control group. Exam questions on dimensioning were also compared. Thispaper will discuss the findings from these analyses.