CNC machining needs a new process paradigm

In today’s CNC machining process paradigm, tool path programming and online control of the machine are separate tasks. The current CNC machining process begins with the CAD model of the part. A plan is then made to determine how to machine the part according to the stock material form, the machining operations and the availability of machines and tools.

Tool paths are generated accordingly and frequently the paths are simulated to detect potential interference problems between the machine tool and the part as well as to check feed rates and tool dimensions. This paradigm has changed little from its inception except perhaps for the addition of the simulation process.

Limited computing power at that time necessitated the division between CNC control and tool path generation, however, the cost and performance of today’s computers no longer warrants this division of labor.

The paradigm is starting to show its limitations with motion control issues in 5-axis machining and high-speed machining, which cannot be properly addressed with the restrictive ISO G-code programming standard. Also, the sensory capabilities and intelligence of the controller are no longer adequate to permit the development of direct model-to-part manufacturing automation.

Another major drawback with the division of labor is that the process is generally open-loop. If there are any problems at any stage, it is up to the operators or programmers to close the loop by identifying and fixing the problems. Fixing problems often requires reprogramming some of the tool paths or changing tooling or fixtures. Not only is this time consuming and expensive, it is error prone because intense manual intervention and judgment are required.

In view of the above discussion, a new CNC machining process paradigm is the need of the hour.

Share and Enjoy:
  • Digg
  • Google
  • Live
  • del.icio.us
  • Technorati
  • StumbleUpon
  • Furl
  • Reddit
  • NewsVine
  • Propeller
  • MisterWong
September 10, 2007 | Filed Under Articles, CNC Machining 

Comments


2 Responses to “CNC machining needs a new process paradigm”

  1. Milind on October 14th, 2008 11:28 am

    Very useful information.You are nicely bridging the gap between knowledge and updating knowledge.
    Kindly place me on your emailing list updating me on CNC.
    my address: [email removed to prevent spam]
    Pune,India

  2. Ivan on October 14th, 2008 1:55 pm

    Thanks Milind. You can subscribe to our rss feed.

Leave a Reply