The Art of CNC Machining

Many manufacturers today are concerned about the future availability of skilled machinists, operators, and engineers. As a result, many high schools are seeing growing support for early manufacturing education.

Technical manufacturing programs typically use a mix of classroom work and hands-on lab projects to provide training and experience. One of the keys to a program’s success is keeping the students interested. At John Swett High School in Crockett, California, talent and ingenuity are turning lab projects into something special, under the direction of Machine Technology instructor Dr. Tony Tammer. Tammer believes that class projects should be functional, instructive . . . And look really good. A particularly fine example – a stunning aluminum tape dispenser in the shape of a snail – is even for sale at the San Francisco Museum of Modern Art MuseumStore. “The task was to design something collaboratively,” Tammer explains. “My CAD class was to come up with a functional product that had some aspect of humor, but also had sophisticated design and curves. I wanted functionality and aesthetics. I showed them some kitchen items in the shape of animals, and a tape dispenser made by a teacher at a local community college. Two female students liked the dispenser idea, and designed one to resemble a snail. “The dispenser is made from half-inch aluminum plate,” Tammer continues. “We mill out the center hole, and drill and tap four 1/4"-20 holes. Then we mount it on a one-inch backing plate fixture, using screws from the back. Locating pins in the backing plate position it in a vise to machine the outline and profile.” After assembly, the results are impressive. “I sent one to the San Francisco Museum of Modern Art MuseumStore,” notes Tammer, “and they said: ‘This is wonderful! We want to sell them.’ We are the only school to have its product for sale in the San Francisco Museum of Modern Art gift shop.” Tammer’s one-year program teaches students AutoCAD?, SolidWorks?, and Featurecam? for designing, and manual and CNC machining to bring their designs to reality. They start on manual machines, and then get hands-on training with a Haas VF-1 CNC vertical machining center, and a Haas SL-10 CNC turning center. “Some kids coming into my class have never held a wrench,” Tammer says. “Since this is their first time in machining, it doesn’t make much sense to put them in front of a CNC machine and push Cycle Start. They need to get a feel for what machining is like, the forces involved. So I leave the CNC component until the second half of the year, when they understand what it means to machine a diameter to plus or minus a thousandth of an inch (±0.001"). They need to know how difficult that is; otherwise, they would have no concept of machining. The projects are designed to teach concepts, but adding art and functionality to the projects keeps the students interested. It’s all about perfection; and when students see folks admiring what they’ve made, it makes a huge difference in the way they approach the class. The whole point is to give these kids some skills they can use,” Tammer concludes. “When people ask me what we make, I say: We make machinists.”