CNC Hot Wire Cutting
I am looking at making one of these for a model plane project.
I think it would be very easy to make one of these machines.
If you skip the A-axis, you just need two steppers, two timing belts (4 pulleys) and four lead screws.
It might be possible to drop the lead screws and just use belts. If that’s accurate enough for a laser cutter then its probably accurate enough for cutting foam.