December 9, 2011
A good machinist is hard to find. Why? It’s a mixture of factors. Machining suffers from the same image problem as the other manufacturing trades, so not enough people enter the field. But this country also lacks hands-on training programs.
Last year Nuts, Bolts & Thingamajigs® (NBT), the Foundation of the Fabricators & Manufacturers Association, surveyed metal fabricators about the most challenging manufacturing skill to find. Welding topped the list—no surprises there. But just behind that came some unexpected results for a sheet metal fabrication survey: Machining and CNC programming held the second and third spots, respectively, sitting several rungs above press brake operation (see Figure 1).
Out of all the skills most desired by the 185 respondents, no single skill truly dominated. Still, the very fact that machining made the survey at all—in a sheet metal fabrication industry study, no less—shows how diverse this industry has become, and how machining stands out among the other skilled trades.
After all, most metal fabricators don’t have that many machining positions. Shops like Ometek Inc., in Columbus, Ohio, offer machining to ensure a broad service offering, but also to complement their principal sheet metal operations.
“We do a lot of machining on components that normal fabrication tolerances won’t allow us to meet,” Paul Siders, vice president of operations, said in a 2010 interview. “So we’ll knock out a portion of a job on, say, the turret punch press, then bring it over to the machine shop to mill and ream holes to tight tolerances.”
So why is a good machinist a rare find? It’s a mixture of factors. For one thing, sources said that machining suffers from the same image problem as the other manufacturing trades, so not enough people enter the field. But the problem also has to do with a simple lack of hands-on training programs.
“Twenty or 30 years ago, machinists went through apprenticeships,” said Randy Pearson, manager, dealer and end-user support, for Siemens Industry Inc. in Elk Grove Village, Ill. “Nowadays, due to all the cuts in schools and government funding, the apprenticeship programs have pretty much died away. Most people coming into the trade now learn how to program the CNC, but they don’t necessarily know how to machine parts.”
The basics of climb milling, cutter engagement, how insert lead angle affects chip thickness, and determining optimal feeds and speeds—some say such knowledge still can be best learned by turning the hand crank on a manual mill. “Nowadays most programs come from the computer, because it’s easier and faster,” Pearson said. “But you may see that when operators are making parts, they may not have tooling set up correctly; they may not have set the optimal feeds and speeds; they’re not getting good cutting conditions; and the finishes on the parts are unacceptable, or perhaps barely acceptable.
“When you’re running a manual machine, you feel the cut conditions, you feel how it’s running, because you’re turning the crank,” Pearson continued. “You can hear how the cut is going, and you can tell the difference between a good cut and a bad cut.”
Software certainly has helped some fabricators ramp up their machining operations. These days on-machine programming has become a rarity, even for low-volume work.
As just one example, Maloya Inc., a Commack, N.Y.-based fabricator, uses CAD/CAM packages to select appropriate tools, toolpath speeds, feeds, and depth of cuts. During an interview last year, Vice President Marc Anderes described a steel header flange that the shop produces with both fabrication and machining technology: The company’s 4-kW laser cut the plate profiles, while a shoulder mill on a vertical machining center finished certain edges to precise tolerances. The software doesn’t eliminate the need for a machinist entirely. After all, Maloya’s production manager, who already had two decades of machining experience from a previous job, helped ramp up the sheet metal shop’s machining operations.
And there’s a need for such experience, said James Wall, deputy director of the National Institute for Metalworking Skills (NIMS), Fairfax, Va. Postprocessed programs sent to the machine aren’t always perfect. “It’s very difficult to troubleshoot if you don’t understand G- and M-code. People do it, but they’re not as efficient. If people know the codes, they can look at the program and see what’s going to happen next.”
Conversational, graphics-based controls also can help, especially for shops that don’t run production quantities. “They allow people to program quickly at the machine, like in a job shop or toolroom,” Pearson said, adding that these advancements don’t necessarily eliminate the value of fundamental machining knowledge, however. The controls help people who learned on a manual machine transition to CNC programming. They also free up the CAD/CAM technicians in the front office to generate programs for higher-volume components.
What if a fabricator wants to machine a noncritical, one-off part and doesn’t want to tie up a more expensive CNC machine? A sheet metal shop may have a few old knee mills sitting in the corner. A worker who can run the occasional one-off on such a machine is probably a very valuable employee.
In these cases, today’s hybrid machining centers—part manual, part CNC—can play a role. “There are lines of toolroom machines that are a kind of hybrid between a manual machine and a CNC,” said Wall. “If you make a part, it will remember how you made it manually, and then it will run it semiautomatically. The prices of these small machines are so competitive now.”
And because machine prices have decreased so much in recent years, it’s not uncommon for shops to run very small lot sizes on the CNC. “It comes down to having someone program quickly and efficiently,” Wall said. “With that, you just can’t compete with a manual machine, even for one-offs sometimes.”
Opinions vary about how valuable training on a manual machine is. Some feel hands-on training will never be replaced, while others feel people can learn code and program a CNC machine without manual machining skills. Regardless, all agree that basic machining knowledge remains paramount. It’s a bit like welding automation: For robotic weld cells, a robot programmer who doesn’t know much about welding may not be that effective. The same logic may carry over to the machining arena.
According to sources, online training shows serious potential. “There’s a whole swath of interactive learning tools now, specifically online training,” said Ben Mund, marketing manager for CNC Software Inc., a Tolland, Conn.-based CAD/CAM vendor. These programs often focus on specific software or machines, “but they do cover basic machining concepts, because they’re needed,” he said.
CAD/CAM packages also can build a knowledge base that can help bring new workers up to speed on the company’s machining practices. “You can save a machining strategy from one part and apply that strategy to another part,” Mund said.
Increased emphasis on jobs certification may play a role too. In October, for instance, the President’s Council on Jobs and Competitiveness announced its Right Skills Now (www.rightskillsnow.org) initiative, piloted by schools and technical colleges in the Minneapolis area. Students undergo a 16-week curriculum and an eight-week apprenticeship program at a local manufacturer. The program builds on the National Association of Manufacturers’ Skills Certification System. The initiative is partnering with NIMS to provide a baseline for that sought-after, machining-specific job training.
“The president’s job council is behind this,” Wall said, “because even in areas where we have 10 to 11 percent unemployment, we’ve got small company owners who are screaming for help.”
Such certifications are likely to become more valuable. In fact, FMA survey respondents said that in the future, new hires likely will need technical certificates more than anything else (see Figure 2).
Some now are perhaps seeing how valuable the old training systems were, including the apprenticeship programs—which happen to be a central feature of the Right Skills Now initiative. As Mund put it, “There is still an element of practical knowledge that will always be necessary and really cannot be replaced.”
The FABRICATOR® is North America's leading magazine for the metal forming and fabricating industry. The magazine delivers the news, technical articles, and case histories that enable fabricators to do their jobs more efficiently. The FABRICATOR has served the industry since 1971. Print subscriptions are free to qualified persons in North America involved in metal forming and fabricating.