Computer Numerical Control: CNC Faceoff

When choosing computer numerical control (CNC) technologies for new or retrofit machinery, use this checklist to help compare capabilities. Look for faster program processing, easier integration and use, and customization capabilities. See checklist, related article links. Engineering interaction: Leave your advice.

07/13/2011


Computer numerical control (CNC) technologies have rapidly advanced. When selecting a CNC, consider faster program processing, easier integration and use, customization capabilities, and tooling speed. Also look at CAM integration, volumetric error compensation, CNC/IT integration, motion system connectivity, simpler integration, setup, use, maintenance, and human-machine interface standardization. Prior to selecting your next CNC machine, see the following checklist based on information from CNC manufacturers. [At bottom, link to related articles and click into a related blog post to leave your CNC advice.]www.siemens.com

CNC faceoff: 18-point checklist

1) What’s your industry? Are there specific needs for your application? High-production markets, such as aerospace, automotive, and medical, may have different needs from others, such as wood, marble, glass, presses, grinding, cutting, or forming.

2) What types of machines will you use? Dedicated turning and milling machines may have different needs than complex 5-axis, multi-spindle, and extended bed gantry machining centers. Needs may differ for prismatic part production, mold and die work, lathes, and other areas in the machine tool industry.

3) What kind of facility are you in? Contract manufacturer needs may differ from those of a small job shop, for instance.

4) Are the controls going onto a retrofit or a new design? Should machine tools be constructed the same way with the same kinds of controls as they have been for decades?

5) Are you looking for just a CNC or also an amplifier, motors, I/O modules, and operator panel?

6) Will you use any existing G code programming, newer plain-language programming options, or a combination?

7) Does CNC operating system design matter to you? Do you want to run one or two operating systems (Microsoft Windows and a real-time operating system) on the same platform?

8) How many axes need to be controlled? Five-axes (and greater) machining, for complex workpieces, require high-end CNC capabilities (often for aerospace and automotive manufacturing). Note that number of axes controlled can differ from spindles controlled, and from simultaneously controlled axes. www.fanuccnc.com

9) Do you need transformation orientation for higher speeds and using programs on different machines? Related functions allow tool center point programming, so part programs can be processed independently of the tool length and the machine tool kinematics. Part programs also can increase speed by reducing part program size compared to a traditional point-to-point method. It also allows the same part program to run on different machine tool kinematics. Compression can help generate smooth transitions at block boundaries to ensure optimum cycle time and increase accuracy.

10) Do you need to integrate with computer-aided manufacturing (CAM) and computer-aided design (CAD) software? CNC integration with CAD/CAM systems speeds time to completion and can decrease downtime between jobs.

11) Will you use simulation for design and feed the results into the control programming?

12) Will your machine tools require customization? Open architectures may more easily support customization for flexible support across many machine configurations. www.siemens.com

13) How accurate do you need to be? What are your tolerances for error or deviation from specifications? Techniques such as CNC volumetric error compensation (as opposed to individual axis compensation) allow higher accuracy, favored for tight tolerances in aerospace, for example.

14) Does information need to flow into the IT environment? Connecting CNC with IT systems enables users to evaluate overall equipment effectiveness (OEE), exchange data with an enterprise resource planning (ERP) system, schedule preventive maintenance, monitor systems remotely, and perform other functions, helping large end users to optimize factories and facilities.

15) Does CNC need to integrate with other motion systems? Integrating CNC with other drives and motors may ease information flow through a facility and provide a better overall view into processes and workflow.

16) Does CNC need to integrate tool and process monitoring, measuring and calibration, and other systems? www.br-automation.com

17) Will you integrate CNC with safety automation?

18) What level of CNC knowledge exists among engineering design, engineering operations, operators, and maintenance personnel? Inquire about simple language commands for setup and programming, maintenance-free controls, and if wearable components are needed. Ask if human-machine interfaces (HMIs) are integrated across CNC offerings, if they are scalable, and if ease-of-use features can decrease the need for training.

Have you recently purchased or are you considering a CNC purchase in a new machine or for a retrofit? Leave your suggestions in the comments box of this Ask Control Engineering post on CNC advice.

-Mark T. Hoske, Control Engineering, using information from CNC providers; see links below.

www.boschrexroth-us.com 

www.br-automation.com 

www.fanuccnc.com 

www.heidenhain.com 

www.mag-ias.com 

www.meau.com 

www.num.com 

www.tenasys.com 

www.usa.siemens.com/cnc 

http://www.controleng.com/channels/machine-control.html



No comments
Consulting-Specifying Engineer's Product of the Year (POY) contest is the premier award for new products in the HVAC, fire, electrical, and...
Consulting-Specifying Engineer magazine is dedicated to encouraging and recognizing the most talented young individuals...
The MEP Giants program lists the top mechanical, electrical, plumbing, and fire protection engineering firms in the United States.
2014 Product of the Year finalists: Vote now; Boiler systems; Indirect cooling; Integrating lighting, HVAC
High-performance buildings; Building envelope and integration; Electrical, HVAC system integration; Smoke control systems; Using BAS for M&V
Pressure piping systems: Designing with ASME; Lab ventilation; Lighting controls; Reduce energy use with VFDs
Case Study Database

Case Study Database

Get more exposure for your case study by uploading it to the Consulting-Specifying Engineer case study database, where end-users can identify relevant solutions and explore what the experts are doing to effectively implement a variety of technology and productivity related projects.

These case studies provide examples of how knowledgeable solution providers have used technology, processes and people to create effective and successful implementations in real-world situations. Case studies can be completed by filling out a simple online form where you can outline the project title, abstract, and full story in 1500 words or less; upload photos, videos and a logo.

Click here to visit the Case Study Database and upload your case study.

Protecting standby generators for mission critical facilities; Selecting energy-efficient transformers; Integrating power monitoring systems; Mitigating harmonics in electrical systems
Commissioning electrical systems in mission critical facilities; Anticipating the Smart Grid; Mitigating arc flash hazards in medium-voltage switchgear; Comparing generator sizing software
Integrating BAS, electrical systems; Electrical system flexibility; Hospital electrical distribution; Electrical system grounding
As brand protection manager for Eaton’s Electrical Sector, Tom Grace oversees counterfeit awareness...
Amara Rozgus is chief editor and content manager of Consulting-Specifier Engineer magazine.
IEEE power industry experts bring their combined experience in the electrical power industry...
Michael Heinsdorf, P.E., LEED AP, CDT is an Engineering Specification Writer at ARCOM MasterSpec.