Design engineers face continuous pressure to enhance product performance while driving down costs. For many devices, converting metal components to plastic is an effective way of achieving both goals.

The original plastic gears worked fine for testing, but they struggled under real load. Over time, wear and slight deformation affected performance. I decided to machine aluminum replacements with the ...

This article was updated March 6, 2023. It was originally published Aug. 1, 2001. Gears—even plastic ones—need to be lubricated if engineers are going to coax the best performance out of them. In the ...