How to make a DIY Hot Knife.
This hot knife useful for cutting plastic and acrylic. It is simply made from a box cutter blade and a soldering iron.
You can also use it to shave Styrofoam. But when working with Styrofoam rather than using a hot knife is probably best to see some of our other modeling tools that we use to work Styrofoam. You can find them under this link.
It is a video that shows you how to make the hot knife and how to use it.