I kid you not, I wasted an entire 4 x 8 sheet of MDF today. I couldn't cut worth a ****. My hand wasn't steady, didn't have patience to begin with, and I think my square was bent. So I went out and bought ANOTHER 4 x 8 sheet of MDF, and a new square. Came home, took one cut off a scrap sheet to practice, and I just called it quits for the day. Usually whenever I build a box, I may have 1 or 2 bad cuts TOPS, but nothing like this before. I use a circular saw btw.