FDM 3D printer for joints/functional parts

[Evil Eye]

I'm a big fan of resin 3D printing, and have used it to great effect to supplement my hobby. Both for conversion parts and full models, it's been a real boon for me, to the point I'm considering getting a bigger one to print larger models (tanks, big monsters etc). However, I have also found another use for it for hobby purposes- homebrew printable action figures!

 

Being a toy nerd, when I realized I could design and print parts for poseable figures I immediately threw myself down that rabbit hole with reckless abandon (much to the alarm of the resident hobby rabbits). I've been practicing on making some basic poseable figures, using printed resin for the main body sculpts and premade plastic joints from Hobby Base to assemble and articulate them. I have a goal of making 1/18 kits to go with JoyToy's figures, to supplement their line and make designs they likely won't touch. For example, the Eldar of both flavours have been neglected entirely, and I have an idea to try making a Lelith Hesperax figure based on her 5th edition model and some Wyches for her.

 

Spoiler

Not 40K related but relevant to the topic at hand, and to prove I'm not a snake oil salesman or Ponzi schemer, here are some of my practice creations. The two humanoids are generic "base body" models intended to test articulation, sculpting and so on. The robot is actually based on a Transformers character, and served as a test of mechanical subjects, stylized work and non-standard jointing. Both stand approximately 11cm high and are meant for 1/12 scale. Yes, the human heads are very uncanny.

 

 

So why the mention of FDM? Well, to quote Senator Armstrong, "I have a dream!". I'd love to be able to print the joints for these sorts of figure "kits" such that, with the possible exception of metal pins if necessary, the entire figure is 3D printable, thus meaning anyone with the proper equipment could make their own action figures from scratch with just materials and the STLs. I have experimented with resin but even the toughest stuff is too fragile for load-bearing joints. FDM meanwhile, whilst IMO useless for detail parts (I've seen some really impressive industry-grade FDM prints and even they were quite "coarse") could be a solution given you're literally printing with plastic and no real detail is necessary; any external coarseness could probably be sanded anyway.

 

However, I know nothing about FDM printers beyond the basic theory, and I don't know if the plastic would actually be up for the job. IIRC the most common filament, PLA, is pretty weak and not ideal for functional pieces. You can however print in ABS, which whilst more temperamental to print and expensive to procure is of course MUCH stronger, being what actual action figures are often made of. I'm imagining the solution would be to print in ABS with a solid infill and very small layer height, thus getting a more "fused" structure and thus lessen the risk of delamination or breakage, but obviously I have no idea if that's actually the case. Also I don't know if POM is available as filament, but I somewhat doubt it as I've never heard of it being used for FDM printers. Obviously, the joints I'm planning on making would be pretty tiny by the standards of FDM, which would be good from a speed point of view (you could print a massive amount of them in a shortish time even on minimum layer height) but I don't know if the joint tolerances would be too precise for an FDM machine to get right?