Experienced gear molders caution design engineers to avoid common pitfalls with plastic gears. One old problem, says ABA/PGT, is misaligned mating parallel-axis (spur and helical) gear tooth surfaces. The solution is the modification of gear flanks by making them full thickness at mid-face-width and tapering them to each edge, as shown in the drawing below. This modification, extending over the full height of the gear tooth, is referred to as crowning. Other useful advice comes from UFE of Stillwater, MN. Operating temperature must be factored into designs using dissimilar materials. If a gearcase is made of metal and the gears are plastic, the distance between the gears will change because of the differing coefficients of linear thermal expansion.
The Space Kid, 11, will be one of the first civilians to have his design manufactured in space by NASA, thanks to the City X Project, which inspires kids to think about new 3D-printed inventions that could be useful for humans living in space.
We searched far and wide for the top employers for engineers. These companies were ranked by engineering professionals, engineering students, and engineering instructors and professors. Does your employer make the grade?
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.