I suggest trying actual nichrome wire of a size anticipated to be strong enough. And for an experiment you could power a similar length of wire in a test not associated with the machine and observe the voltage required to produce the desired temperature. That would help select the rating of the transformer you need to purchase without any guesswork. And it will avoid disrupting the machine operation.

Yes sir, that's the plan.

 

How many do you have and what VA rating are they?

I have two of the OA-100 and one OA-300. According to information at the link, these have max VA ratings of 240 and 720 respectively. I thought I had more!

I was planning to wind these things with magnet wire and made a bunch of calculations regarding how much wire would be required given the gauge and number of layers. Happy to share that worksheet if it helps.

 

Just don't make the mistake that most people do when making hot wire foam cutters. The wire, whether plain steel or nichrome doesn't need to be glowing red hot, only hot enough to cut the material. Making it glowing red only makes it soft and burn out before it's time.

 

The required heat energy varies with the material and ge advance speed, and the desired neatness. And, like soldering, some heat energy is stored in the thermal mass of the wire. So the selection is not simple.
How much cycle time is allowed for the cutting off??That matters a great deal.

 

I have two of the OA-100 and one OA-300. According to information at the link, these have max VA ratings of 240 and 720 respectively. I thought I had more!

I was planning to wind these things with magnet wire and made a bunch of calculations regarding how much wire would be required given the gauge and number of layers. Happy to share that worksheet if it helps.

Thanks, but I don't think I will need to wind a primary given the other options discussed, and secondary turns will be found empirically.