NC/CNC Introduction

Numerical control (NC) and computer numerical control (CNC) refers to the process of automating machine tools (such as routers, mills, lathes, and cutters) by programming commands into a storage and extraction medium (Narayan, 2008). End-to-end design aids/programs such as computer-aided design (CAD) and computer-aided manufacturing (CAM) are currently the most widely used storage and extraction mediums (Narayan, 2008). CAD and CAM software programs, which utilize a post-processor system to mine and extract files and communicate the commands necessary to operate a specific machine directly to the machine in question, have almost exclusively replaced analog NC methods due to their enhanced convenience/all-inclusive design suites, accuracy, and ability to automate and coordinate multiple machines and/or processes simultaneously (Reintjes, 1991).

CNC’s, while exceptionally fast, accurate, convenient, and multi-capable, are not without criticism. Critics point to safety and equipment issues such as crashes (caused by erroneous commands that move a machine in a manner which causes damage to the machine and/or flawed outputs) and backlash (excessive or uneven wearing of a machine due to consistent over-emphasis or pressure on one specific and limited range of motion) (Farin, 2002). While all-inclusive end-to-end CAD and CAM software suites such as DESKAM, Gibbscam, and HSMWorks, do offer users step-by-step command entry and auditing platforms that greatly aid in eliminating data entry errors, it is still imperative that human programmers/imputers are aware of and account for human safety issues and machine wear and damage issues that crashes and backlash can cause (Farin, 2002). As with any tool, a CNC software suite is only as effective as the designer/programmer imputing code, and as such, should never be looked at as a fail-safe. QOS implementation should also be explored.  Experienced mentoring and apprenticeship programs are equally necessary components of a successful CNC software training curriculum as they are when dealing with hands-on analog NC training programs (Smid, 2008).

References

Farin, Gerald; Hoschek, Josef and Kim, Myung-Soo (2002). Handbook of computer aided geometric design [electronic resource]. Elsevier. ISBN 978-0-444-51104-1.

Narayan, K. Lalit (2008). Computer Aided Design and Manufacturing. New Delhi: Prentice Hall of India. p. 3. ISBN 812033342X.

Reintjes, J. Francis (1991), Numerical Control: Making a New Technology, Oxford University Press, ISBN 978-0-19-506772-9.

Smid, Peter (2008), CNC Programming Handbook (3rd ed.), New York: Industrial Press, ISBN 9780831133474, LCCN 2007045901.