I’ve wanted to build a hot wire cutter for quite a while but have been too nervous about the electric part of it. Well, I’m finally biting the bullet.
I’m starting with this –
– a vintage Louis Marx Model 1209 50 Watt model train transformer. My reading has lead me to believe that this is the easiest solution and the one which requires the least electrical engineering expertise. 
My first try at a bow is made from 3/4″ PVC tubing. It seemed very wobbly but the second cross piece helped quite a bit.
For thick wire to carry the electrons from the DC transformer to the cutter, I’m going to use this extension cord.
I cut down the short arms as they were just too long and wobbly, then used zip ties to hold the power cables in place.
A close-up of the connection. The power cable is clamped between two washers. The spring / cutting wire attaches to the eye of the two eye bolts.