The length and diameter of wire determines the power you need. I have a 12 volt computer power supply that I control with a variable resistor. I'm just using some 30 awg craft wire, no sure what it's made of, it lasts for quite a while and then snaps. Like shoelaces it breaks at the worst time. I'm going to pick up some Kanthal at the local vape shop. I did a video of mine back in 2009, it's terrible. Been using the cutter a lot over the years. I might make a new video.
I did this with a wire cutter with no dimmer switch. And kelly was right, if you slow down at all it just makes a big void at that spot. I'm thinking if I get a decent power supply with a dimmer switch, and use a motorized rotary table, I think I could get the correct speed and wire temperature to make a much better cut.
All you need is a small transformer. Doesn't need to be DC, just <12v for safety and appropriate gage resistance wire. Diimer upstream of transormer of course. Best, Kelly