Related Glossary Terms
- computer numerical control ( CNC)
computer numerical control ( CNC)
Microprocessor-based controller dedicated to a machine tool that permits the creation or modification of parts. Programmed numerical control activates the machine’s servos and spindle drives and controls the various machining operations. See DNC, direct numerical control; NC, numerical control.
On a rotating tool, the portion of the tool body that joins the lands. Web is thicker at the shank end, relative to the point end, providing maximum torsional strength.
Last month, CTE’s 'CNC Chef,' Bob Warfield, polled the readers of his CNC Cookbook blog about what they like and dislike about their current CNC controls. On the ‘dislike’ side, he reported that those surveyed mentioned shortcomings such as:
- “Inadequate work offsets or other features needed to control the coordinate system.”
- “Inability to do web monitoring of the control.
- “Lack of features related to Tool Data Management.”
- “Missing features [such as Conversational CNC] that make shop-floor programming easier.”
FANUC Corp. CNC Engineering Manager Paul Webster sympathizes. All of the capabilities longed for in those comments are available in FANUC controls—but not on every FANUC-controlled machine, he said.
“When we sell a control, we sell it to a machine tool builder. Machine tool models are differentiated based on performance and cost. Builders compete against each other and differentiate among their own lines on those bases,” he noted.
He explained how the machine tool builders look at a full menu of CNC options, and choose the ones they want based on where they want to position a given model in the marketplace.
“The machine comes with the control capabilities the builder expects that user will need. And they can’t necessarily foresee everything the end user is going to do with a given machine in the future.”
What the end user may not always realize, however, is that that if their machine doesn’t have an option it turns out is needed, it’s probably not too late.
“If someone buys a lower-end machine but then finds that they need some capability that wasn’t standard, they can usually have it added for a price—and not a high price for most features.”
He offered work offsets as an example: “You might get a machine in your shop that doesn’t have adequate work offsets for what you want to do." You may not know it, but that option is still available, he said. “FANUC offers expanded work offsets.”
The company has an aftermarket support team that can let a user know if what they want is either an option that’s installed and just needs to be turned on, or something that can be purchased and installed—or else really isn’t available for the control they have.
His point is, if your machine tool doesn’t have the CNC capability you need, don’t assume it can’t have it. It may not be too late to...take control.
Much more on CNC controls is coming in the December issue of CTE.