While there are all sorts of ways to build a hot wire foam cutter, this design from [jasonwinfieldnz] is both interesting and imitable. If you don’t already know it, nichrome wire is nifty stuff ...

(Okay, sure, you actually need the spikes and wire-bending holes, too. The spikes are for reaming cut pipes, which is pretty important, and using the bending holes help you to control the ...

Those stick-type hot wire cutters from the craft store that plug into the wall aren’t much better than a knife. The actual cleaving of foam is easier, but dragging a long, hot flexible wand ...