Trying to make a Nova with twists. But I can't find the right tolerance and PLA doesn't seem to be very good for action figures.


Still, not bad for a first try.
Not bad at all! Have you considered using or prototyping ball joints?
Back when I first got into 3D printing one of the biggest questions was what type of filament was I going to settle on.
I did hours of homework on ABS vs PLA and what pointed me towards ABS was durability.
Since then I've been a member of several 3d printing (3D printing for profit) groups on social media and a very big complaint was that PLA had a much lower melting point than ABS.
I've often read that peoples items were shipped either in or through environments where temperatures reached that of Godzilla's foul taint... arriving in a ruined PLA blob of "not what I ordered, give me a refund"
It sickens me to think that might happen to anyone that commissions me, especially from here. So... ABS it is.
Joints are an entirely different beast. I've recently had a back and forth "argument/discussion" about using various methods and materials (even flexible filaments) for making functional joints.
The problems encountered (no matter the type of design, mine or theirs) have always been: Joints will strip leaving them loose (unacceptable) or joints will break. Both those problems exist even for flexible materials.
Resin would be the best way around that. The second best way, which is still expensive yet less expensive than resin printing is injection molded joints MADE for action figures.