I have a feeling it's designed for larger wire and stranded wire. I'm using it for #10, 12, and 14 romex. first impression was it's junk, but with copper are $3.65 a pound I was going to make it work. First thing I did was remove the guide so I had room to move the wire and keep it in the sweet spot. Then I put a light 1/8" gap between the lower rollers. this allowed me to start the wire into the cutter, then guide it left and right to keep the actual wire running along the side of the wheel, and skin the coating. After 15 min of adjusting, and 2 hours of running wire through I have mastered how to easily strip solid wire. I definitely recommend it, just be aware it takes a little time to master.
Bernhard Bloom 
