|Design for inspection should become the norm, says GE's Robert Tait.|
First there was design for test, then design for manufacturing, and now manufacturing specialists are looking at the next step. "I'm trying to get engineers to design for inspection," says Robert Tait, research manager for inspection and manufacturing technology at General Electric Co. in Niskayuna, NY. "If we get involved in the design cycle, we can use colors, distinct shapes, or fluorescent dies to highlight differences," Tait says.
There are many ways the level of inspection can be improved if it's considered early in the development cycle. "Optical character recognition is good, but the engineering department needs to use characters that are easy for the vision system to read," he continues. Getting the most from inspection techniques will help improve quality, he adds. Putting a small notch on washers so they can be distinguished from similar parts is another way engineers can help improve inspection functionality with little effort, he adds.
Tait describes a helicopter engine being built by GE which has a challenge that requires a well-thought-out examination scheme. Two blades in the engine vary by only 0.0025 inches, yet using them in the wrong application can hamper reliability or hinder performance. Engineers devised a solution, using reflective strobe lighting.
Though Tait has been involved in vision technology for much of his career, he hasn't been too enamored in the unfulfilled promises that many vision providers have made. "There are lies, big lies and promises from vision providers," Tait tells the 850 attendees at the DVT Global Business Conference and User Group Meeting.
That's changing now as vendors leverage the power of semiconductors, which are declining in price as their processing capabilities rise. Having a good inspection scheme and cameras that function as promised is critical in many applications, particularly those which have life and death considerations. "With aircraft engines, 6 Sigma is not enough. We need 9 Sigma," Tait says.
Tait also mentions a startup that is working on 3D vision, adding depth capabilities. Though initial cameras are not useful for industry, he feels the idea may find success as it evolves. "It's crude now, but watch this space," Tait says.