This is another planetary gearset I attempted after the first one (Planetary Gearset 02). I wanted to increase the number of planet gears to try and keep it aligned better (which worked) but didn't fix the problem that it's hard to hold the center ring and spin the outer ring. I added an index line to the inner ring so if you hold the outer and run the planets by putting a pen in one of them and spinning it around, you can see the sun ring spins much faster.
Filamentum Extrafill PLA
After printing separate each planet gear by putting a screwdriver or similar rigid rod into each planet and flexing it slightly toward and away from the center of the sun gear. That should break any bridging at the build plate layer and let the planets all run.
Designed in Solidworks 2018, using built-in ISO straight gear profiles. Once the teeth and pitch diameters were worked out, I used the "Flex" tool to twist each gear to give it the angled gear teeth, then mirrored the body to create the herringbone.
LibreOffice Calc was used to work out the number of teeth, pitch diameter, and twist angles.