This is my DIY hot wire foam cutter. I built it out of wooden booms and an acoustic guitar string. I put a bit of tension on the guitar string and fastened it using an alligator clip and screws. The hot wire foam cutter is connected to my DIY bench power supply that my dad and I made out of an old PC power supply. The hot wire foam cutter works great and cuts through foam really easily. It can make complex shapes out of foam and even an airfoil in a wing.