A Day in the Life of a CNC Programmer
And, what with the cost of materials and the more alarming cost of lost time, there’s also very little room for error.
Of course, you programmers already know all that.
Those of us who aren’t programmers, however, got curious about life on the shop floor and decided to ask some ESPRIT customers about what you face on the daily grind.
If you ask Kent Collins, senior NC programmer at the Halliburton Manufacturing Center in Duncan, Okla., essential requirements of the job are being able to understand the design intents of engineers, as well as “being able to make up for shortcomings in a blueprint when the blueprint is not clear on the engineer’s design intent.”
Furthermore, he says, a programmer must know machining processes and how to optimize them, in addition to understanding tooling capabilities.
In short, the job is multifaceted in terms of knowing how abstract concepts can best be translated to physical reality in the most efficient means given the laws of physics as we know them.
To do this, a programmer must have both hard and soft skills — hard skills being easily quantifiable and soft being those of the intangible sort. Hard skills include knowing the machine, the software and the needs of the shop, while soft skills include assets such as people skills and problem-solving creativity.
According to Collins, programmers who were once machinists are most adept at understanding the big picture on the shop floor.
“They need to know what the machine is capable of doing with the program they are creating. They need to be familiar with metals and how they react to machining, as well as the tooling used to machine the metal,” Collins says. “Typically, programmers of this sort have, at one time, been machinists … .
“It’s sort of like baking a cake,” Collins continues. “You can read a recipe, but unless you know that your oven has hot spots in it, or cooks ‘best’ at a certain temperature, or know that real butter isn’t the same as margarine, your cake, or pie — or whatever — will turn out to be a flop.”
While making a delicious "cake" is a hard skill, some of those softer skills can help programmers better utilize their practical abilities.
“All programmers have to have the capability of working with people and taking time to analyze problems logically,” Collins says. “Generally, programmers are kept busy, at a moment’s notice, with ‘last minute’ changes in processes due to factors such as material supply, machine breakdowns and routing changes.”
Nate Price, CNC programmer at the Valparaiso, Ind.-based Task Force Tips, says that programmers must also learn to bridge gaps in communication, knowledge and expectations.
“A common sticking point is physics,” Price says. “The people asking things of us often ignore the limitations imposed by physics, and I suspect this issue has plagued machinists since the trade began. Program revisions are not one-to-one. What appears complex to the customer may actually be quite simple to the programmer, and vice-versa.”
Gary Carter, a CNC programmer with Quantum Components of Fredricksburg, Texas, has had his fair share of experience in bridging gaps between divergent viewpoints on how to get the job done.
“We have a part with .060" slots that go pretty deep,” Carter says. “Someone else may look at the part and, from his perspective, it’s a straightforward part: ‘A couple of slots and pockets, no problem. I could get my 8-year-old son to program that at the machine.’ Well, my .05" end mill begs to differ. That ol' boy is hanging out so far that when he gets to a corner he wiggles, squirms and whines like a politician who got caught cheating on his wife.”
In cases like the above, it’s takes the “soft skill” of dealing with the expectation and the “hard skill” of knowing how to get the job done anyway.
“That's where and why we have to get creative with the tool path,” Carter says. “ESPRIT allows us the flexibility to control everything from speeds, feeds and lead in and lead out to the cutting-edge tool paths like trochoidal milling. Without the proper combination, we are left with a pile of broken end mills and scrapped parts. Even though it’s a ‘simple part,’ I would not be profitable without the right tool path. Tool path is everything.”
Mark Grecko, a CNC programmer for Hoerbiger Corporation of America, says that misunderstandings regarding programming basics cause the majority of headaches.
“Many do not understand that a request to change a tool at any given process is not necessarily a point and click,” Grecko says. “At times, it takes time.”
Many also do not understand, he continues, “that program simulations and verifications do not cover all variables at the machine, and that caution needs to be taken on the first part until programs have been sealed, or confirmed good.” Likewise, design engineers at times do not “grasp the idea of design for manufacturing and overcomplicate the design, making it a time consuming task to program and machine.”
“Drafting departments sometimes dimension or tolerance parts from generic templates and create parts with tight tolerances that are unnecessary for fit, form and, or, function, and that add cost,” Grecko says.
Before computers made the splash that made them crucial to life as we now know it, the machinist was responsible for turning a blueprint into the final product via manual machine tool. The role of the programmer is, in part, to ensure a strong connection between the blueprint or solid model and the machinist in a climate of increasingly complex technology and complex jobs.
“The bottom-line challenge is how to capture and manage all of that various knowledge so that it can be applied repetitively, while at the same time growing in new knowledge and discarding or archiving old knowledge,” Collins says. “This is why, more often than not, a programmer at one time was a machinist. If you take away the computers, a machinist is the one who must understand all the processes because he or she is the craftsman who is ultimately responsible for producing the end product.”
No easy feat.
Still, Price says that programmers often take the lion’s share of the heat when jobs go awry. “Programmers are often blamed when a setup isn’t going right, even if the job has run well several times since the last revision,” he says.
Things are much the same in Mark Grecko’s corner of the world. “Operators do not take seriously the tool set-up instructions and blame programs when tools bump and grind parts or fixtures,” he says.
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