When marking out a blank for turning we often wish to include or exclude certain features. Cut a clear acrylic disk the diameter of the swing of your lathe. Drill a 1/8” hole in the center. Place a leg of your dividers in the hole and scribe a series of circles 1” apart. Drill a 1/8” hole at each point where the concentric and the radius lines cross. In use, position the disk to maximize the blank, place an awl in the center hole and a pencil in the appropriate radius hole. Then rotate the disk with the pencil point to mark the blank.