Cutting Tool Engineering
August 2011 / Volume 63 / Issue 8

Marking Time

By CTE Staff

The manufacturing arm of a Detroit nonprofit civil and human rights organization is employing a laser marking system to identify and code its production, prototype and R&D parts.

Focus: HOPE was founded in 1968 by Detroit community leaders intent on healing the wounds from the city’s 1967 riots while addressing some of the issues that spawned them. The group’s efforts range from establishing supplemental food programs to creating educational opportunities that help people learn skills and enter the economic mainstream.

Among those opportunities is the Machinist Training Institute. As an extension of those training programs, Focus: HOPE launched a manufacturing operation in 1982. Then, to enable students to earn degrees through local universities, the organization formed a coalition in 1989 with universities and manufacturers called the Center for Advanced Technologies (CAT). Degree candidates gain real-world experience in Focus: HOPE Manufacturing, which makes parts for customers, including the U.S. military, and conducts manufacturing process R&D.

FocusHOPE CMT 8-11PrdT.tif
Courtesy of Focus: HOPE

On the Focus: HOPE shop floor, Engineering Technician Dennis Simmons loads friction stir-welding test specimens into the Columbia Marking Tools U-15 EcoMark laser marking system.

Recently, Bruce O’Neill, CAT project manager, contacted Columbia Marking Tools, Chesterfield Township, Mich., seeking a way to mark metal and plastic parts with alphanumeric characters, bar codes, logos and other graphics.

O’Neill noted that most of CAT’s work involves R&D on special military projects to refurbish and remanufacture older components. “The identification marks that we place on the parts vary widely,” he said, adding that the amount of required information also varies. “Part production ranges from one to 25 parts per job.”

O’Neill said Focus: HOPE already employed dot peen marking equipment, but some parts are too small to dot peen. In addition, dot peen marking can damage materials that workharden. Less-desirable alternatives include adhesive labels and, in the case of small parts, “bag and tag—putting them in bags and marking the bags,” O’Neill said.

Brad Byrne, sales engineer for Columbia Marking Tools, said, “Columbia has had an ongoing customer-supplier relationship with Focus: HOPE for a number of years, primarily doing contract part marking work when marking could not be dot peened.”

Columbia Marking Tools’ large offering of marking technologies enabled it to “come up with the best solution,” Byrne continued. “Focus: HOPE wanted more advanced marking technology, and our recommendation was Columbia’s 15w U-15 EcoMark pulsed fiber laser diode industrial laser marking station.”

Higher-power lasers can mark faster, but the 15w machine is a good fit because Focus: HOPE does low volumes, minimizing the requirement for fast cycle times, according to Byrne.

The marking station is on casters and in a 24"×30"×68" enclosure with a 10"×14" table. O’Neill specified a portable marker so operators can move it to the appropriate machining cell. “While one part is being processed, the laser is actively marking the next part,” he said.

The marking head’s 163mm F-Theta-Ronar lens with 7.5" focal length covers a marking area of 100mm ×100mm. The laser’s frequency can be manipulated for power intensity, speed, pulses per dot, distance between dots and the number of passes per object being marked.

Common graphic formats and CAD files can be programmed for laser marking. The ability to download CAD files was important, “so we can put any kind of image we need on the part,” O’Neill said. For example, he cited requirements for “up” or “down” arrows to indicate orientation.

According to O’Neill, the system enables Focus: HOPE to mark parts that it couldn’t previously because of material hardness or part size. “We also have a lab here,” he said. “We are doing studies in direct metal deposition and friction stir welding, and we have to make samples to test. The laser helps us mark those samples so we can track the parts through the testing program.”

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