Do people usually print Technic parts in ABS? How much difference is there between ABS and PLA for Lego?

11 hours ago, 2GodBDGlory said:

Do people usually print Technic parts in ABS? How much difference is there between ABS and PLA for Lego?

Don’t bother printing ABS. It’s difficult to print, produces unhealthy fumes, and can be brittle. PLA works fine for Technic. PLA can scratch LEGO bricks when forced against each other, but that only happens when the part has the wrong tolerances.

43 minutes ago, TechnicRCRacer said:

Don’t bother printing ABS. It’s difficult to print, produces unhealthy fumes, and can be brittle. PLA works fine for Technic. PLA can scratch LEGO bricks when forced against each other, but that only happens when the part has the wrong tolerances.

Thanks! That's what my impression was, but I wanted to make sure.

12 hours ago, 2GodBDGlory said:

Do people usually print Technic parts in ABS? How much difference is there between ABS and PLA for Lego?

I don't think most people do.  ABS is a much more challenging plastic to print. I don't usually print ABS for LEGO but sometimes it can be the better material to use. I found PLA can deform over time under stress. The axle holes in my PLA train wheels lost some clutch power after being connected to Technic 6L axles for a year or so.  They pull off now with barely any effort. The ABS printed wheels still got good hold on the Technic axles. The PLA for the Powered UP male connectors is still fine after a year or so since the Technic hub and train hub female sockets don't put much pressure on them. 

I print ABS in a spare bathroom with the exhaust fan running like the fume hood back in the high school chemistry lab class.

Best to experiment and see what works well with your printer and application.  There are so many variables in 3D printing. 

49 minutes ago, dr_spock said:

I don't think most people do.  ABS is a much more challenging plastic to print. I don't usually print ABS for LEGO but sometimes it can be the better material to use. I found PLA can deform over time under stress. The axle holes in my PLA train wheels lost some clutch power after being connected to Technic 6L axles for a year or so.  They pull off now with barely any effort. The ABS printed wheels still got good hold on the Technic axles. The PLA for the Powered UP male connectors is still fine after a year or so since the Technic hub and train hub female sockets don't put much pressure on them. 

I print ABS in a spare bathroom with the exhaust fan running like the fume hood back in the high school chemistry lab class.

Best to experiment and see what works well with your printer and application.  There are so many variables in 3D printing. 

Ok, thanks. So ABS is higher quality, but more work (and more expensive, I think). I'll probably stick with the cheap, simple PLA for now, but maybe someday I'll get more serious and move up.

I've heard that ABS becoming one of the leading filaments in the industry was largely an accident, i.e. it just happened to be first, rather than being inherently great - and it's enduring popularity is a bit of a mystery to me. At my work we basically skipped ABS entirely and went straight to PETG - much better all round. Good strength, easy to work with, and less brittle than PLA. Others I know also swear by ASA for ABS-like properties with less fuss, but I haven't tried that myself.

Maybe it has to do with costs. I have purchased spools of ABS for less than spools of PLA.  PETG and ASA are pricier than PLA. I do like TPU, although I haven't printed anything LEGO compatible with it yet.