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March 2002

Building the tools to advance science: the shop at FL1

If it's true that you’re only as good as your equipment, then much of NCAR and UCAR's atmospheric research is dependent on the equipment built by designers, engineers, and instrument makers in ATD's Design and Fabrication Services group.

 
Instrument-maker David Allen works with a computer numerical controlled machine tool. (Photo by Carlye Calvin.)

Based on the lower floor of FL1, the 14-person group works with researchers to create the inlets, mass spectrometers, radar systems, and other custom-built devices that transform scientific visions into viable experiments.

"A scientist has an idea of what they want to accomplish; we figure out how to build that instrument to make it do what it needs to do," explains Jack Fox, the group manager. "We have been building instruments for the atmospheric science community for 40 years. There aren't many problems we haven't seen in that time."

The group has completed more than 960 projects dating back to 1963. Over the years, its equipment has changed with the times; it now features advanced computer-aided design capabilities and computer numerical controlled machine tools, or CNCs.

Scientists at NCAR and other research institutions give the machine shop high marks. "They can do unique stuff," says ACD's Fred Eisele, who has turned to the machine shop for a number of instruments, such as the vacuum system for the four-channel mass spectrometer. "It's really handy to have them here."

 
Design and Fabrication Group manager Jack Fox working with a flat plate radar antenna. (Photo by Carlye Calvin.)

A job typically begins with a scientist sitting down with Jack or another designer to explain the scope of a new research initiative (although scientists sometimes arrive with detailed drawings). Key design questions include: Will the device be mounted on an airplane, a ship, or a truck? Or will it be used in the laboratory or suspended from a balloon at 120,00 feet? What sort of forces will it be exposed to? Above all, what must it be capable of doing in order to make the necessary measurement? Atmospheric research needs are so demanding that some instruments must be built to rotate 360 degrees; others have to create vacuums, capture large aerosols, or survive 100-mile-per-hour winds and temperatures of –70 degrees Fahrenheit.

"The design process allows us to be creative," says Karl Schwenz, one of the shop’s three designers. "The way I look at it is: What needs to happen and what’s the best way to make it happen?"

Because the needs of atmospheric scientists are so specialized, the shop typically is called upon to design equipment that has no precedent. One of Jack's major projects at present, for example, is to design a large balloon-borne telescope gondola for the Max Planck Institute in collaboration with HAO. In recent years, he and his fellow designers have faced such tasks as creating a more efficient aerosol inlet for the collection of large aerosol particles and a dropsonde dispenser for the ER-2 airplane that can be operated remotely by the pilot.

 
Designer Karl Schwenz with a Solid Works model of the Differential Absorption Lidar (mini DIAL) system. (Photo by Carlye Calvin.)

"In the past five years, weíve been involved in the design of 20 new instruments," Jack estimates.

The design work often begins with hand-drawn sketches that focus on the instrumentís basic concepts and requirements. Designers next create three-dimensional models of the objects with a software program known as Solid Works.

Once the design is completed, the task of actually building the new device falls to an experienced team of instrument makers. They use state-of-the-art CNCs to machine complex surfaces and make precise cuts to within 1/1000 of an inch.

On a recent day, instrument-maker Jerry Dryer demonstrated how a CNC works. First he programmed the machine to mill a solid slab of aluminum, then he positioned the metal in precision vises and began the machining process. The CNC moved the aluminum horizontally and vertically, its cutting edges shaving away bits of metal.

Does the development of such sophisticated machines mean that the instrument-makerís role is becoming obsolete? Not at all, says Jerry, who has worked as a machinist for 28 years.

"You have to have an understanding of what the metal is going to do and how to program the CNC," Jerry explains. "Once it starts cutting, you have to look at it and make sure the metalís going where you want it to go."

"This machine is dumb,"he adds. "If you tell it to cut ten inches [beyond the aluminum slab], you'll break a $200,000 machineóand that doesn't make anybody happy."

The CNCs, which have become far more sophisticated in the past few years, allow the shop to create more complex instruments than in the pastówhich is a major benefit to scientists. "We just were not making these kinds of parts nine years ago," explains Walter Hodshon, an instrument maker.

Jack believes that scientists will ask for more and more advanced instrumentation as the machine shop becomes capable of turning out increasingly complex devices. "It's one of those situations where, if you can build it, they will come,"he says. "The demand for the instruments follows the capability of what we can design."

The prospect of creating more complicated equipment doesnít daunt the machine shop staff at all. "It's very challenging and a lot of fun," says Jerry. "You run into different problems all the time. It's like piecing together a puzzle."

•Bob Henson


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UCAR > Communications > Staff Notes Monthly > March 2002 Search

Edited by David Hosansky, hosansky@ucar.edu
Prepared for the Web by Carlye Calvin
Last revised: Wed Mar 13 17:08:40 MST 2001