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.
When you think of the DARPA Robotics Challenge, you may imagine complex humanoid contraptions made of metal and wires that move like a Terminator Series T-90. But what actually happened at the much-vaunted event was something just a bit different.
Traditional dev kits are based on a manufacturer’s microcontroller, radio module, or sensor device. The idea is to aid the design engineer in developing his or her own IoT prototype as quickly as possible. A not-so-traditional IoT development kit released by Bosch aims to simplify IoT prototyping even further.
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