Johns Hopkins University
Fall/Winter 2006
Vol. 4, No. 1

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OUT OF AFRICA
   The Diaspora and Beyond

A MAJOR CHANGE

> SHOP TALK


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Shop Talk

For an exacting trio of machinists, turning space scientists’ dreams into reality is all in a day’s work.

Shop Staff
Above, l-r, Scott Spangler, Gabe Morris and Steve Patterson.

 

With a combined 40 years of experience among the three of them, they can help turn an idea scribbled on a napkin into a PhD or fulfill the promise of a NASA mission. An interlocking amalgamation of Yankee know-how and mechanical aptitude, they transform researchers’ dreams into reality.

Think of them as “Mechanics’ Eye for the Science Guys.”

Their show runs every day on the ground floor of the Bloomberg Center for Physics and Astronomy, and in each episode they confront a new problem: to be considered, solved, built, tested, and maybe sent into outer space.

Patterson at computer w/ 3D drawingIt’s an ensemble cast: the clean-shaven Wise Guy, Scott Spangler, who can build almost anything out of nothing but an idea. The reserved, bespectacled Smart Guy, Gabe Morris, who thinks carefully before he speaks. The genial, goateed Good Guy, Steve Patterson (left), who sits nonchalantly between a computer and a lathe, greeting their frequent visitors.

They are the trusty trio of the Physical Sciences Machine Shop; the agile hands to the agile minds of the Krieger School’s departments of Physics and Astronomy and Chemistry.

At first glance, the shop seems like an ordinary mechanic’s workshop: something grinding, something whirring, something banging—and rock music always blaring on the radio. But it doesn’t take long to notice there’s no grease on the floor; no dust on the tables; no discarded, half-finished jobs in the corner. In fact, for all of the work that goes on down here, the shop is immaculate.

“You’ll never see a machinist with an unkempt yard,” boasts senior machinist Spangler, a 25-year veteran of the shop.

Instead of pinup calendars, there’s a picture on the shop’s wall of Henry A. Rowland, Johns Hopkins’ first professor of physics. It’s an apt tribute. If Rowland could have transported himself from the late 1800s to today, he undoubtedly would have found himself among kindred souls in the Physical Sciences Machine Shop. Rowland engineered a ruling engine with precisely calibrated diffraction gratings that revolutionized astronomical spectroscopy.

It’s that exacting attention to detail that engineers and research scientists have come to count on from Spangler, Morris, and Patterson. Years oftheoretical planning of a satellite or a telescope can all come down to a moment of proof based on a machinist’s work: a single instrument,deliberately fabricated to minutely specific calculations.

“For the work we do, everything needs to be made just so,” says Steve Smee, director of the Instrumental Development Group (IDG), an engineering services group within Physics and Astronomy that specializes in developing instruments for scientific research. The group’s engineers frequently turn to Patterson and his crew for help.

“The things they build need to be made perfect, exact. We can’t find out halfway through putting something together that it wasn’t built right, that it doesn’t fit exactly right. If that happens, the whole thing’s worthless. But these guys are good,” says Smee, who worked his way through college as a machinist before going on to earn his PhD in engineering.

Everything that the machinists make—whether it’s a lens holder for a spectrograph or the super-structure for a dual-array monochromator—is designed very specifically for a single purpose. “The role of a machine shop in any physics and astronomy department is to make new and unique instrumentation with little direction,” says principal research scientist Stephan R. McCandliss. “In the ‘olden days’ [like Rowland’s time], the machinist would take a sketch and run with it. Now they are taking high-level drawings and with the help of a computer, turning them into our dreams. These guys are the best, they have the best equipment, and they can make complex instrumentation from a few simple sketches.”

McCandliss’ Rocket Project group has launched over 70 sounding rockets that have been used to observe things like the Earth’s aurora, Venus, Jupiter, the Halley and Hale-Bopp comets, and a solar eclipse. He employed the machine shop to build the payload that houses the spectrograph and the telescope for his recent Long-slit Imaging Dual-Order Spectrograph (LIDOS). Thanks in part to the work of the machinists, McCandliss says, LIDOS came back to Earth safe and sound to report what it saw.

When Patterson was hired to manage the shop seven years ago, he quickly saw that his mission was to bring the outmoded machine shop into the 21st century—to match the cutting edge science being conceived in the same building. “The equipment was basically still from the 1960s and 1970s,” he says. “Really old school.”

Patterson employed some very modern methods to get the equipment he needed.

Pointing to an electro-discharge machine (below) that takes up almost a full corner of the shop, he says proudly,“I got that on eBay.”

discharge machine from ebay

metal cutout sample

The electro-discharge machine employs an electrically charged wire to cut a solid cube of metal into tightly interlocking parts (left).

 

 

 

 

The machine employs an electrically charged wire to cut a solid cube of metal into two tightly interlocking parts with such a small distance between them that they appear to be one. In minutes, it will produce two very closely fitting interlocking halves, perfect to make a doorhinge, like the one Spangler constructed for the Hopkins Ultraviolet Telescope (HUT).

“I got that at a bank foreclosure auction two years ago,” Patterson continues, gesturing to another hulking piece of machinery. In fact, it’s a high-speed machine that cuts anything from stainless steel to plastic into the exact dimensional specifications. The machine contains a tube that concurrently squirts bright blue coolant and lubricant on the newly honed object to ensure the integrity of the cut and the longevity of the cutting edge.

Though Patterson and his team can still work from traditional paper blueprints (or some notes scribbled on a Post-it) like the machinists in Rowland’s day, the majority of the machines are now powered with computer numeric controlled (CNC) technology. Using CNC, the machinists employ computer-aided design (CAD) programs to create a 3-D model, which is translated into language a machine can understand by a computer-aided machining (CAM) program.

The machinists do, however, still use a lathe from 1963, which has been updated with a computer monitor to communicate with the CAD. “It’s still the same machine being made today. Same hardware, just new software,” explains Spangler.

Patterson’s most recent, and perhaps valuable, update to the shop comes in the human form: Gabe Morris, who answered Patterson’sad on Monster.com for a senior machinist two years ago andquickly became an integral part ofthe team. Morris supplies what Spangler calls, “the mentalitybehind the trade.”

All three men are as comfortable working with undergraduate and graduate students as they are with faculty and engineers—even students from outside Physics and Astronomy. If the engineering machine shop in Maryland Hall is too busy, budding engineers sometimes come to get advice and assistance in completing their senior projects.

Patterson, Spangler, and Morris love to recount one of their favorite real-life machine shop parables on the importance of minding the details.

Spangler at workA few years back, a group of engineering undergraduates came for help in building a bridge for their senior project.

“They brought us their idea written in marker on a napkin,” recalls Patterson. “They were in a big hurry because it was due in two weeks. We could tell they were disorganized and not too sure of what they were doing, but they needed our help so we built for them.”

Morris adds, “They had spent most of their time calculating angles and gussets and all the forces the bridge would hold. They were really serious and even came in to clean the metal so Scott could weld it. It was obvious they were smart. They just missed something.”

Spangler finishes the story: “They didn’t tell us the exact specifications and dimensional requirements for the bridge. We just built what they told us to. When they got there to present their entry, it was 10 inches too short.”

 

 

The relationship between scientists, engineers, and machinists is often mutually dependent. The creative visions of scientists like McCandliss and his group rely on the exacting design of engineers like Smee and his group. And ultimately it can all come down to the deft skills and exactitude of machinists like Spangler, Morris, and Patterson. McCandliss describes the work of the machine shop nicely:

“I always think of them this way. Do something the first time, it’s art. Do something for the second time, it’s science. If you do it the third time, it’s engineering. What comes out of the machine shop is somewhere between art and science.”

 

Shannon Dunn is a freelance writer and cultural affairs manager for the History of Medicine Department at Johns Hopkins.