Chris, a.k.a. Lost Wax, turned his son into a knight for Halloween in 2016. The costume required an armor build in my current favorite material, EVA foam. Chris constructed the armor but had to learn how to make it so that the metal plates could pivot and allow for more freedom of movement. He says:
What I came up with was really simple, and super cheap, using 1/4 inch clear plastic tubing that you can get at any hardware store. And the end result looks really good.
You can see the process in the above video.
If you’d rather read about the design, you can do so at Chris’ website.