I have a dremel/rotary tool, and I feel like this would make all my problems easier on projects, but I found a new one. A dremel rounds everything off, as the bits are always a circular shape, or if they arent, they rotate basically turning it into one. I need to not only sand an angle into a perfect 90 degrees, but also on another section, smooth out the edges and angles in a section to create a square shape that concaves and sinks into the shape. Any advice that the experts have out there?