thicknessers

Thicknessers, also known as thickness planers in North America, are woodworking machines designed to produce boards of uniform thickness and smooth a face. They remove material from the opposite face of a board as it is fed between rollers against a flat reference bed. The depth of cut is set by adjusting the cutterhead height or using a depth stop, determining the final thickness.

Typical operation begins with preparing the stock: one face is jointed flat and an edge is squared. The board is then fed through the thicknesser with the prepared face against the reference bed. The cutterhead removes material from the opposite face until the board reaches the desired thickness and one flat, parallel face remains, ready for further milling or finishing. After thicknessing, boards may be re-flatted or re-edge jointed if needed to achieve precise dimensions.

Types and features: Benchtop thicknessers offer modest width capacity and portability; floor-standing machines are larger and suited to workshop use. Common features include adjustable fence for edge thickness control, variable feed rates, and built-in dust extraction. Blades may be straight or spiral, and some machines include digital readouts or depth gauges. Capacity typically ranges from about 6 to 13 inches (150–330 mm) or more in professional models, with length capacity governed by bed length.

Safety and maintenance: Always ensure boards are dry, free of nails, and supported during feeding. Keep hands away from the cutterhead and use push sticks. Regularly check blade sharpness, align the bed and fence, and clean dust from the cutterhead area and rollers to prevent snipe and kickback.