Wood Planer Types Wood Planer Types. Wood planers are machines that whittle away material. All planers have a drum with blades that spin rapidly to thin the material and straighten the edge. They usually have infeed and outfeed desks. Because the blades are rotated quickly, planers leave a smooth edge, sometimes scalloped. These edges are clean enough to be glued together into larger boards. Benchtop thickness planer If you’re in the market for a benchtop thickness planer, there…