I wanted to better understand how planetary gears work, with the goal of being able to understand it well enough to explain it to my 7 year old, so I printed this out last night.
I ended up watching chunks of older videos from GearDownForWhat to try to figure out how to assemble the thing and found some relief in:
It really just does take some fiddling. I got all my gears phased and meshed and turning well, only to realize I'd placed them into the final ring at a skew. It's purely cosmetic and meshing all those gears required a fair bit of work and profanity, so I'll probably leave that as an exercise for another day, but this was a fun easy print and I've enjoyed playing with the gearbox. I'll need to do a little more research to fully explain the thing and answer my kid's questions, but it's a fun start.
I ignored all the infill settings and just did the whole thing at 20%, .15 layers, .4mm nozzle, 2 shells in PLA. Mine works fine, but I'd probably look back at his infill settings if you're going to run this thing a lot.