When Tufts’ high-energy physics group needed 300 “phototube optical boxes” for a major experiment, they knew who to call: the Science and Technology Machine Shop.
For almost four years, the machine shop has been involved in the design, prototyping, fabrication and production of those boxes for MINERvA, based at the Fermi National Accelerator Laboratory in Illinois. The project studies what happens in the rare instances when neutrinos—tiny particles with zero mass and zero charge—meet the nucleus of an atom. The boxes house and shield special tubes that convert photons given off by these interactions into electrical signals, which are used to measure the interaction.
“The jobs are getting bigger,” says Denis Dupuis. “It used to be five or six pieces. Now it’s many, many more.” Photo: Joanie Tobin
Building components for this kind of high-profile experiment is typical of the work done at the machine shop, which is located in the Science and Technology Center on the Medford/Somerville campus. With more than 60 years of combined experience, machinists Larry McMaster, Denis Dupuis and Scott MacCorkle support research projects for more than 10 academic departments. They have constructed bioreactors for the Biomedical Engineering Department, operating room devices for the School of Medicine and heat sinks for the Electrical and Computer Engineering Department.
McMaster, the machine shop’s manager, has seen considerable changes in his line of work over the 40 years he’s been at Tufts. For example, there were no computer-controlled machines when he started; every part had to be made by hand. He does not miss the good old days. “Computerized is definitely the way to go,” he says. The machine shop staff not only keeps up to date with drilling and milling machines, they also use the latest computer-aided design software.
“Computerized is definitely the way to go,” says Larry McMaster, the machine shop manager. Photo: Joanie Tobin
Another significant change for the shop has been the increase in separate pieces requested per job. “The jobs are getting bigger,” says Dupuis. “It used to be five or six pieces. Now it’s many, many more.” Fortunately, technological advancements with computer-programmed milling machines make it easier to complete such large orders on time.
Finally, the number of machine shops on campus has shrunk dramatically. “When I started here, there were eight or nine machine shops at Tufts,” says Dupuis. That was 12 years ago. As the needs of the university changed, the smaller machine shops gave way to just two large shops serving the entire Tufts community: the one in the SciTech Center and the Bray Lab Machine Shop, which is part of the Mechanical Engineering Department and mainly serves students working on class projects.
Healthy competition between the two remaining shops makes on-the-job successes especially sweet. As MacCorkle describes a nearby computer-controlled, three-dimensional milling machine, he looks at it and smiles, remembering a SciTech shop coup. At one point, the Bray Lab shop had deemed that piece of equipment unfixable and was about to dispose of it, but the SciTech machinists stepped in and took it back to their shop.
MacCorkle and Dupuis eventually solved the problem: the computer coordinates for using specific tools were incorrect, meaning that the computer controlling them couldn’t find specified tools and therefore couldn’t complete the tasks. Now the machine has become one of the busiest at the SciTech machine shop.
“I’d like to think that the students learn something when they come to visit us,” says Scott MacCorkle. Photo: Joanie Tobin.
But work at the shop isn’t strictly technical; it entails a fair amount of personal interaction as well. McMaster points to the problem-solving sessions with students who come for help. “In most cases, they know what they want a part to look like, but they don’t know how to achieve the finished product, which machines to use or how to operate the machines,” he says.
Part of his job, McMaster says, is to “inform the students how we’re going to approach the project, what tools we use and what we need from them.” Fortunately, the students’ technical drawings have improved over the years. “They used to be on napkins,” says Dupuis, chuckling.
Yang Yu, a Ph.D. student in biomedical engineering, says the machinists “are always willing to help. Scott MacCorkle even came up to my lab to help me troubleshoot a machine I could not take to them.”
Recently, the machine shop staff have started asking students to come back and tell them how the pieces made in the shop worked out in the experiments for which they were designed. “I’d like to think that the students learn something when they come to visit us,” MacCorkle says, “that they go away with some added knowledge beyond what they are studying.”