An 18-year-old brings in $300,000 a month selling 3D printed 'reload can holders.' Here's how he comes up with unique product ideas.

"I didn't know if it was that good of an idea, but I just posted it on Instagram to see how it would do. The video went wild.

13 3D printing projects you must try

D printing is a fun hobby and there are many useful items that you can make. Here are 13 projects you can try out to test ...