I had to bevel my insulation for my garage foundation at a 45, so I decided to build a cutter. I used two scrap boards, a small gauge stainless wire, and a battery charge, along with some wood screws to hold it together. I screwed the boards at a 90, then drilled a small hole for the wire to feed through 4 inches from the intersection of the two boards. This gave me a 45 on the wire in relationship to the base. I used the battery charger at 6 volt. It would cycle off once and a while, and did this less at 6 volts.
I am going to place a picture link on a separate reply to see if it helps with the disappearing text.