I used the circle cutter to cut a few ragged 10 1/2 inch holes in 1/4 inch plywood. Despite tightening the bolt to the point I was afraid it would break, the guide still slipped a little and made ragged holes. I'm pretty skilled with power tools / guides etc. but couldn't get this one to work well. Feed rate was critical for a clean consistent cut. Too much pressure and the plastic arms flex which makes for a crooked cut. Cord was constantly tangling with guide. When bits ran slightly crooked they bound up and broke. Pivot point kept trying to rise up out of the guide hole. Too many things to watch and hold onto to make the thing work. I'm returning this one and looking for a simpler solution.