I have PowerSpec Ultra 3D printer (Flashforge Dreamer/Creator clone) and Simplify3D software. The black gear was printed using PLA, medium printing quality, 20% infill, and 20% outline overlap. The gray gear was printed using ABS, high printing quality, 100% infill, and 20% outline overlap. The white gear was printed using PLA, high printing quality, 100% infill, and 50% outline overlap. Why does the gray gear look terrible?

gears.jpg