Making a hot wire foam cutter

When presented with the unique opportunity to slice 24 4-inch styrofoam balls in half, what would you do?

After looking at one of them, I decided that there wasn’t any way in the world that I was going to cut them on the bandsaw. There’s enough sawdust in the shop as it is, without adding styrofoam dust to it.

I’d remembered seeing a hot wire foam cutter on the MAKE: blog so I went looking for how to make my own hot wire cutter. The MAKE: blog pointed to flywoodkb’s hot wire foam cutter on instructables so I started with that as my basis.

Hot wire cutter Here’s what I came up with. Visit my hot wire foam cutter set on Flickr for more pictures.

Instead of the CD case project box, I just used a three wide plastic outlet box from HD to hold the dimmer and transformer. I cut the tabs off the sides since they were just in the way. Since I had some 1-by material around, I used that to make a small bow for holding the cutting wire. Twine around the top is used to tension the wire and can be adjusted as the wire heats and lengthens.

Since I was tasked with cutting foam balls in half, I made up a jig to help hold them in place and guide the wire at the right height. It’s nothing more than two pieces of 1-by two inches in height placed at a small angle on a board. This allowed me to hold the ball in place with one hand and while the other hand held the bow so the wire would ride the 1-by material and cut a nice clean line.

Monday June 26, 2006   ·   Permalink