The primary thing people complain about is the aesthetics of the FDM print lines. They give the appearance of a hobbyist look. Sanding and finishing is one way to alleviate that. I bet PLA doesn’t sand amazing since it’s mostly just sugar but PETG sands reasonably fine. I have sanded PETG and finished with spar urethane/polyurethane for commercial products to give them a nice professional glossy sheen with no print lines. I mentioned in a sibling comment XTC-3D as another option which is probably the best hobbyist product for this, but it’s kind of a pain to work with and it’s a little expensive. So not great for commercial use. For home use though it’s totally fine and indeed usually gives better results than the urethanes mentioned above due to lack of yellowing and being thicker and better at filling in the lines and giving a smoother appearance. People could honestly probably just use that product without sanding and be mostly happy with it because it does a good job of hiding the FDM lines even without sanding
We run one of the largest print farms in North America. Reflecting parent's sentiment, BambuLabs' P1/X1 series are capable of substantially finer layer height and consistency (0.08mm), with SLA-quality results. We dumped all of our FormLabs because of it.
We don't sand any PLA, anymore. If we need to control the surface texture, it's largely a function of the qualities of the filament and print speed.
Great to hear. I have a resin printer at home and almost never use it because it’s such a messy, sketchy (in terms of chemicals) pain to deal with. The fact that FDM is good enough now for a lot of aesthetics use cases is great. I’ll probably still have to reach for the resin printer for high pressure use cases (like injection molds) but the fact that FDM can do more than before and make commercial grade parts is really good news
The physical characteristics of the print surface also change at lower layer height with high infill. I wonder if that might be good for your use case.
I'm mentioning it because we were surprised how easily our molds separated when we moved to Bambu and didn't understand why. It turned out that the combination of the layer height and high print speed that gave the prints their smooth, matte finish with standard PLA also made them functionally non-stick.
We also discovered they're also at least tough enough for a car to drive over, which may have just been because of the thickness. I also sometimes print nylon and polycarbonate automotive parts for a mechanic which seem to have excellent rigidity and durability.
Indeed I suspect FDM is good enough for a significant hunk of use cases as you’re outlining.
As FDM printing evolves the number of use cases it cannot solve seems to be shrinking. Probably we need to get into physics requirements to cover the requirements that FDM does not solve these days. Which is great, it makes general plastics manufacturing super accessible to the masses when we can arrive at this. I wish there was a general FAQ thing available people would be able to use to determine what manufacturing process would be necessary at the product planning phase. Because I feel like if people knew that they could just 3D print plastics at scale that a lot more people would be willing to innovate in the hardware space, which is a space well known as being difficult to enter and fraught with all sorts of monetary and regulatory land mines.
In my experience matte filaments hide the layer lines much better. Between that and the overall quality of recent printers like the Bambu or the Prusa Mk4, I don’t find the need to do any post processing.
I do want to challenge you on this. I don’t have evidence matte filaments are better. I would love to see an example of these filaments outperforming. I believe it is true, but would love to see a demonstration!
It isn’t really that they’re better as filaments, it’s just that the matte nature makes them less reflective and therefore you don’t see the layer lines as much.
Performance wise, most matte filaments are more brittle and have worse layer adhesion due to the matting pigment, but do a good job at hiding lines as the reduction in specular highlights reduce the visibility of them. Another good trick is fuzzy skin setting with both length and depth settings at 0.4x-0.8x layer height.
