Foam Cutter
I built this hot wire foam cutter to cut foam wings for my custom made airplanes. By heating a thin wire, you can melt through foam. I used nichrome wire, which is used in guitar strings (so I bought the wire from a music store). There are different thicknesses of wire available - I didn't get a chance to experiment with different wires yet. I read online that the nichrome wire tends to snap after a couple of uses, but my first wire has not snapped yet.
The design is shown in the picture above. There is a spring between the side arms, which pulls on the ends of the wire. This spring is needed because when the wire heats up, it expands, and the spring allows the wire to stay tight.
I modified a computer power supply and used the 12V output to power the foam cutter. After about one year of use, the power supply burnt out, and I now use a 12V 5A transformer.
The design is shown in the picture above. There is a spring between the side arms, which pulls on the ends of the wire. This spring is needed because when the wire heats up, it expands, and the spring allows the wire to stay tight.
I modified a computer power supply and used the 12V output to power the foam cutter. After about one year of use, the power supply burnt out, and I now use a 12V 5A transformer.