June 23, 2013
June 23, 2013
June 26, 2013
23.1336.1 - 23.1336.15
Using Simulation to Improve the Efficiency of CAM and CNC InstructionThe use of industry-type CNC machines, as opposed to “trainers”, for learning NC operations inEngineering Technology programs, presents several challenges. Key amongst these is the potential fordamage to the machine, tooling, work piece and injury to users from improper operation. To preventthese occurrences, significant effort must be expended on the part of instructors and lab personnel invetting programming assignments completed by students, and in supervising set-up and operation of amachine. Faced with fewer resources and increasing class sizes, simulation techniques are becomingincreasingly useful to help departments better manage their resources, and not just for the educationalbenefit of the student.This paper describes efforts to utilize simulation in several courses in a Manufacturing EngineeringTechnology program that heavily utilizes CNC technology. To do this, accurate digital models of CNCmachines have been created using a CAD system, and converted into simulation models within anindustry standard NC verification application. For each of the classes that utilize a CNC machine, thesimulation model, along with tool and fixturing libraries, are available for students to use in verifying theprograms they create for assignments and project work. Students are introduced to the simulationsoftware at the start of an introductory course to CNC operations, through a single homeworkassignment. The effort in using models is minimal: Selecting tools from a library, adding and positioningstock geometry (and final part when a machining accuracy comparison is required) in a fixture (often aKurt machinist’s vice), setting up the work coordinate system (G54 location), and loading the NCprogram. These steps mirror those that will be performed by the student on the actual CNC, and so arereinforcing the student’s experiences. Evidence of how the use of simulation is helping to increase thepreparedness of students, reduce the occurrences of programming errors and machine crashes, andimprove the efficiency of time spent in the lab will be presented.Additionally, this paper will discuss how the same simulation environment used by students in preparingprograms for machining in the CNC lab, can be used during lectures to assist the instructor in explainingthe concepts of manual part programming. Examples that were previously written by hand, with theprogrammed actions being illustrated on a white board, are now displayed graphically during thelecture. This aids students in visualizing the effects of various programming instructions, and isparticularly useful in explaining the more challenging concepts such as cutter-compensation. By makingthese available outside of class, students are better able to review the lecture materials to deepen theirunderstanding of manual part programming. Students are also required to use simulation in homeworkprogramming assignments. With this, they are able to test the effect of each line of code they write asthey create a program. This can be viewed as a form of immediate feedback that encourages students tocritically evaluate and correct their work prior to submission. It offers a “first line of defense” inproviding assistance, and is helpful to the instructor in this regard. A final benefit of this approach to theinstructor is that it can be used to assist in grading these same homework assignments.
Yip-Hoi, D. M. (2013, June), Using Simulation to Improve the Efficiency of CAM and CNC Instruction Paper presented at 2013 ASEE Annual Conference & Exposition, Atlanta, Georgia. https://peer.asee.org/22721
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