Bookmarks
Forum.reprap.org
3D Print Hobbist:
Forum.reprap.org is another important 3D printing forume with around 1M visits per month.
/r/3DPrinting
3D Print Hobbist:
It’s not really a forum in the traditional sense but this subreddit represent an important online 3D printing community nonetheless. Newbies beware: comments can be harsh, in the Reddit spirit. Upvoted posts are very often pictures of very cool 3D prints (or print fails!). Expect some very in-depth conversations on technical topics, too. A must for advanced 3D printing users.
Quora 3D printing topic
3D Print Hobbist:
Quora is a platform where people ask questions and other users provide educated, in-depth answers. It sets itself apart by the quality of the answers provided, which are usually quite elaborated and made by experts. The 3D printing topic is quite active, with a few top users providing the bulk of the answers. Savvy marketers often use Quora to build their online reputation on a given topic. Note that questions on Quora are not often from 3D printer users but more from people outside the 3D printing field asking general questions, so if you got a question about your clogged extruder, maybe that’s not the best place to ask.