Google+ social media has grown rapidly since Google created a communities feature at the end of 2012. Google has described Google+ as not simply a social-networking Web site, but also an authorship tool that associates Web content directly with its owner/author. Google+ is now the second-largest social-networking site in the world after Facebook. Estimates are that 300 million individuals use Google+ every month. Here are some of the engineering groups on Google+ we think are worth a look.

3D-printing Community

The main Google+ 3D-printing Community has 56,000 members and a new post every hour or so. Even though anyone can join, there’s precious little spam. Members generally stay on topic, which means that a lot of posts turn into collaborations between strangers. If the flood of information on this Community’s news feed is too much, log into plus.google.com with a Gmail account and search on 3D Printing to connect with niche communities, people, and pages. While there, follow SketchUp, Google’s free CAD software that generates files used by many 3D printers.

Makers, hackers, artists & engineers

This open group covers everything from the basics of electronics and making things, all the way up to advanced engineering. Lots of active discussions here with about 68,500 members.

Mechanical engineer

There are about 1,700 members in this community discussing CAD and CAM software, mechanical design, and structural engineering topics.

Engineering

With about 1,800 members, this group has posts covering many different facets of engineering. Those we saw ranged from interesting images to links for articles covering current events in engineering.

Engineer Memes

Engineering jokes and cartoons, gifs, videos, and funny pages. About 800 members.

Design engineering

D&E describes itself as a sandbox for ideas. There are a lot of discussions of Kickstarter projects as well as show-and-tell posts about new developments. There are about 600 members.

CAE, FEA, CFD & Engineering Simulation

This focused group discusses computer-aided engineering with a particular emphasis on structural engineering and finite-element analysis. There were 584 members when we checked.

Engineering & green technology

This group of about 400 users posts information about how to get energy from nature without affecting it. Typical topics cover getting electricity from wind energy, solar energy, biomass, and other natural sources.

CNC Machining & Manufacturing

This group of about 550 members is a good place to find discussions about new developments in metal machining and manufacturing.

Aeronautical & Aerospace Engineering

For aviation aficionados. There are about 500 members. We found discussions ranging from coverage of air show crashes to home-built planes.