If you thought 3D printers were only good for building tiny plastic toys then you're mostly right, especially when it comes to desktop models. However, there are people using the technology to realize grander designs, to create bridges and even buildings. Here are 10 projects promising to make 3D printing bigger and better. Bridges
A Dutch start-up, MX3D, plans to use robotic arms to weld layer upon layer of molten steel together into a steel bridge across a canal in Amsterdam. MX3D hopes to begin work on building the bridge, using the process seen in an artist's impression above, in September.