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by fsloth 167 days ago
I actually think what you suggest _would_ be brilliant if there was a printer that printed as nice and detailed parts as Lego does from ABS. The digital ecosystem for that would be crazy.

But.

Modern consumer printers are way better than decade ago but they still sort of suck if you want any fine details.

"It shouldn't be hard to print pieces that can snap together."

It's actually quite hard to print pieces that are functional and look nice.

Modern consumer 3D printers sort of suck for small details still. If all you print are Lego Dublo sized parts. And print them from ABS. You might succeed _sometimes_.

PLA the cheapest default plastic for filaments for extruders loses fit quite fast (I've tried). So ball joints etc will get loose pretty soon.

"Would there be any downside to this approach?"

Well, the adventure currently is the printing part and it's mostly not fun but one of those activities masochistic engineers (like myself) take up as a hobby.

The consumer 3D printers are improving! Maybe one day. But the material physics are not that comforting there.

1 comments

Can confirm everything. PLA is completely unusable for this as it quickly deforms under constant pressure, so it is impossible to have a stable press fit with it. ABS would be the obvious choice (since Lego is ABS), but it's difficult to print. Generally, a press fit with ABS that can be handled by kids (so easy enough to create and remove), but still being sufficiently stable so that it can be handled, requires extremely tight tolerances which you will not be able to achieve with an FDM printer. Even very good FDM printers with small nozzles will have dozens of micrometers in tolerance, which is too large - pieces will either be almost impossible to fit, or they will just fall apart at the slightest movement. Resin printing is better, but again, the material is too soft and will not be able to withstand the pressures long-term. Even if you use special durable resin, it will deform quite quickly under constant pressure.
I would suggest PETG.