Today I tested a new hot wire gear cutter made of balsa, copper, and 21 AWG nichrome wire. I cut an eight inch cylinder of ice with the table-mounted chainsaw and placed the cutter on top of the cylinder. I still need to make an axle-mounted guide to keep the cutter steadily moving vertically without tilting or rotating, but I decided to do the first test without a guide.
As current was applied, the cutter started to slowly work its way through the ice. My power supply was only producing about 50W; it was enough to do the job, but I'd like to find a larger transformer that will cut faster and enable cutting of larger gears.
The finished gear had several flaws due to the lack of a guide but otherwise was beautiful. Making cutters like this one will take quite a bit of time, but the actual cutting time is very short. I think that this will be our gear cutting method for this year's event.