Why Did Eric Betzig's Part Inspector Get Turned Off?

Eric Betzig built an inspector with about 30 cheap CCD cameras set all around a part. It measured every piece coming off the machine in a fraction of a second, to sub-pixel precision on an edge or a hole, and rejected any part that missed the blueprint tolerances.

He put one on a machine shipped to New York, and it started rejecting parts. Eric Betzig places the specs in the era of GE and Jack Welch's Six Sigma push. He says Six Sigma means precision like 10 to the minus 6, a level nobody can achieve. The old method used a coordinate measuring machine to check only some parts. As long as the parts bolted onto the axle, the result was good enough. Companies wrote tolerances so tight that even a factor of five off still left a part that would bolt on.

The shop turned the inspector off, let the parts go through, and measured them the old way. Eric Betzig's first lesson was that productivity is king. The camera system hampered productivity, so the next project, done with his dad, had to increase productivity instead.