I was thinking of using foam in a future project, so I played with the idea to make my own foam cutter to help me with that future build. It turns out a foam cutter is rather easy to make!

How was it made?

This hot wire foam cutter works by connecting a nichrome wire straight to a set of batteries. This will heat up the nichrome wire enough to be able to cut (melt) through foam.

The nichrome wire needs to be as thin as possible to be able to work with two AA batteries. I’m using 32 SWG (Standard Wire Gauge) wire for this project, which means it has a diameter of about 0.275mm. The wire can be found on eBay with different gauges to choose from.

   To connect the nichrome wire to the batteries, I attached crimping lugs to the ends to make the connections easier. Some screws hold all the wires in place and help tensioning the nichrome wire.

Finally, I made a custom handle out of wood to mount the batteries on and handle the wire. It sort of looks like a catapult, but sits well in the hand and still allows finer work when cutting foam. Another advantage of this shape, is the fact that it’s portable, as opposed to a desktop version. It’s up to you to figure out which handle will best suit your needs.

 I’ve tested the build with some XPS foam, which is quite dense, and was able to cut at a rate of about 5mm/s for a thickness of 3cm. Regular and thinner foam will cut more easily.