3D printing is something that would solve SO many of my day-to-day issues, but would not be worth it because it would be endless one-off project after one-off project, each one requiring a different filament or different head or etc or…
—Patrick
We have a Prusa Mk 3 filament printer and my husband uses it for making custom/prototype parts and the like all the time (everything from shelf spacers to race car parts). We just have the assortment of nozzles that came with the printer (and use the .4mm for the majority of prints) and spools of PLA & PET (depending on the project). Unless you're getting into some really crazy materials or want to print in multiple colors, you only need a few basics. He uses the free version of Fusion 360 to create objects.
I print miniatures and the filament printer kinda sucks for that. If all you want to do is print miniatures, resin is the way to go. We have a Phrozen Sonic Mini 4k resin printer and an Anycubic Wash & Cure. Resin requires more work on the printing side, since you're dealing with resin (which can be stinky and should be handled with gloves since it can cause skin irritation) and it requires rinsing (with alcohol) and UV curing, but it requires much less work on the finishing side and the results are absolutely worth it. Filament miniatures will require a lot of finishing work and there is a high risk of breakage of the tiny arms/legs/weapons when you're prying them out of the supports. Resin miniatures essentially come out ready to paint, though the longer you let them cure, the better. After doing the intense curing with the UV light they're still a little soft, just letting them sit for a few days in sunlight will finish hardening them.
Star Wars Legion-scale miniatures (about 32 mm, 1:47 scale), filament & resin. I don't have any pics of the same model in each material, but these models were created by the same person so are very similar in design and detail.
When Padmé came off the printer, she was completely encased by support material. I used clippers and dental picks to remove the supports. You can see a lot of filament bits and strings still on her that would need to be sanded or picked off. Her face is kind of blank and the gun is a mess because filament printers have trouble with fine details at this scale (0.25mm nozzle for this one).
Resin only needs a few supports (they look like a few bits of scaffolding) that I just snipped off. Echo has sharper fine detail, which is what makes resin ideal for miniatures. He just needs a little touch-up sanding. (His prosthetic arm is missing because it was printed as a separate piece).
I printed a 6" Captain Rex figure in filament and it turned out fine (except I snapped off his viewfinder while removing the supports *cry*).
Before
After (about 5 hours to clean him up)