Cad Instruction Techniques For Advanced Assembly Modeling And Mechanisms Design

The Industrial Technology CAD/CAM program at Western Washington University (WWU) provides training to technologists in a range of CAD and CAM related areas. Critical amongst these is training in how to model large assemblies with moving components that can be simulated and analyzed. This takes place within the context of an advanced CAD course, ETEC 361, that uses the Assembly Modeler and Mechanisms application within Pro/Engineer®. This paper summarizes the approach taken to do this, offers observations that have been made on how it benefits CAD/CAM majors and discusses the challenges that remain. After providing background on the IT-CAD/CAM program and the objectives of ETEC 361, a description of instructional approaches and assignments that students are required to complete is given. These include instruction in Top-down Modeling techniques and in assembling mechanisms for simulation and analysis purposes. Students have a basic understanding of the difference between the top-down and the bottom-up approach from freshman CAD classes. In this advanced CAD class the use of skeletons is introduced as another approach that applies the top-down methodology. Examples of open-ended individual projects where students get to select a mechanism to model and analyze are presented. In addition an overview of the strategy adopted and experiences in conducting a collaborative team project for creating a complex mechanism will be discussed. This strategy enables a realistic model of an assembly with over 100 components to be modeled, simulated and analyzed within a 10 week term. The paper concludes with a discussion of observations made on how students benefit from the instruction, assignments and project work in this advanced area of CAD. This includes their ability to assimilate and apply both the mechanics and strategies of advanced assembly modeling and the challenges faced in collaboratively creating large assemblies.