Wire is measured in gauge. There are several different gauge standards so it is common to use the decimal measurement instead of gauge now. Nichrome wire and other non-ferrous metals use the AWG gauge standard, American Wire Gauge, and this is the standard I use on my Web site but I also list the decimal. You can use any wire size you want to. Foam can be and is cut with wire sizes from 40 gauge (.003" dia.) all the way up to 11 gauge (.091" dia.). The temperature of a straight wire in room temperature calm air can be calculated. A given temperature will result in a specific current flowing through a specific diameter wire. It doesn't matter how long the wire is, a given current flowing.
Can a 12 volt power supply power a foam cutter?
A 12 volt power supply will power up to 24" of 26 gauge wire. This would include nearly all table top foam cutters which is the most common type of foam cutter, and would include small bow cutters. This is why 26 gauge is the most common. 24 gauge to 30 gauge has also been used for table top models.
Most foam cutters take a moderate current and low voltage. For example, with a 12V transformer, you put in 120V and you get out 12V. That is a ratio of 120/12 or 10:1. The current is increased 10 fold and the voltage is reduced 10 fold.
How much nichrome wire can a 9 volt battery power?
A short piece of 40 gauge wire has been used with a 9 volt battery to cut very thin (.020") and narrow strips of foam for air surfing walk-along gliders. Two D cell batteries can power a 4" piece of 32 gauge nichrome wire in a small hobby hand held foam cutter. A 12 volt power supply will power up to 24" of 26 gauge wire.
From the temperature chart on the Jacobs site... for the same temperature (i.e. 800*F) 30AWG needs only ~1.5 amps whereas 26AWG will require ~2.6 amps. It probably comes down to finding a suitable power supply. .WARHAWK. Thanks, My power source is rated at 3.6 A, will it melt the wire ?
As it turns out, the voltage requirement for 18" of nichrome wire at 800F is 10.4 volts so instead of a 24 volt output transformer, a 12 volt output, 50 Watt transformer can be used. The current capability is 50 / 12 = 4.1 amps, well above the 2.6 amps required.
What material do I need for a hot wire cutter?
Other material: Actual nicrhome wire, not guitar wire, and here is why. For a hot wire cutter, you would need to fashion a holder that meets your requirements, as well as some nichrome wire.