Evaluation of Simulation for CNC Training in a Community College Setting

Jonathan A. Morell, :Ph.D., et. al.

Computer numerical control (CNC) refers to substituting human control over machine tools with computer control. Such a substitution has numerous advantages. More machines can be operated at once. Precision and accuracy in repetition can be increased. Very complex machining can be done. Robots can be put to work.

Training people to do such programming is problematic however, because students need real machine tools and need to practice machining real stock into real parts. This hands-on requirement results in very expensive training because tools, shop floor space and machining stock are expensive to acquire and maintain. Because of the resource limitations:

• The number of machines available to students is much more limited than the number they may encounter in the workplace.
• Practice time is limited.
• Students are risk-averse because of fear of breaking a work-piece, or worse, breaking a machine tool.
  

Another problem is that some important information cannot be provided to students because teaching that information requires visualization that is impossible in the real world. As an example robot arms move in tiny zig zags which are numerous and fast enough to appear as a smooth motion to the human eye. The nature of the real motion is important, however, in understanding robot programming.

This project was an attempt to assess the value of computer simulation (from the Deneb Corporation) in ameliorating these difficulties. Fixed choice questionnaires were used to gauge student satisfaction with the simulation, while interviews were used with instructors. The overall finding was that simulation does in fact work well to improve CNC training, but that two difficulties inhibit its wide spread use. First, it takes deep technical expertise to set up the simulations. Second. the software (and hardware needed to run it) is very expensive, far beyond the budget of community colleges. Deneb is now taking steps, both in terms of its software and its business models, to lessen these problems.