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Chapter 21

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Chapter 21

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  1. Chapter 21 Processes Used to Separate Wood Materials

  2. Objectives • Edged tools • Planers and surfacers • Lathes • Sawing • Drills and boring machines

  3. Introduction • There are 9 major types of processes used in manufacturing wood products: planing, jointing, shaping, routing, turning, sawing, drilling, boring, and mortising and tenoning.

  4. Planing • Planing or surfacing is a process that mills wood to a uniform thickness and produces a smooth surface. • There are 3 major types of machines used for planing: knife blade planer, abrasive belt planer, and jointer. • The jointer is the preferred machine from removing stock from the edges of boards. • The abrasive bed planer is a safer machine than the knife bed planer. They are used in furniture manufacturing. They have heavy sanding belts.

  5. Shaping • Shaper is used for producing intricate shapes required for molding or window framing. • Shapers produce straight line or design patterns along the length of the stock. • Often special purpose wooden guides or fences are fastened to the shaper table.

  6. Routing • The router is used to add simple round or decorative shapes to the corners of stock, tables, and counter tops. • Routers are popular in the furniture making and boat building industries. • CNC routers are often used when a number of identical parts are required.

  7. Turning • Turning on a wood lathe is removing stock using a lathe tool called a chisel. • Chisels come in six different shapes: gouge, skew, parting tool, diamond point, round nose, and square nose tool (fig 21-13, page 313). • Initial turning operation is called roughing. It is done at low speeds of 1000 rpm or less.

  8. Sawing • Saw cuts made across the grain are referred to as crosscut sawing. • Cuts made in the direction of the grain are referred to as rip sawing. • Circular saw blades are used for most of the machine powered saws: portable circular saws, radial arm saws, cutofff saws and panel saws.

  9. Drilling • Machine drilling, or boring, of holes in wood is normally done with a drill press or a boring machine. • The tools that are used to produce holes are called (drill) bits. • To ensure accurate and safe operation, the work piece is held securely in a fixture bolted to the table of the drill press.

  10. Boring • In the furniture making industry, holes are often bored for inserting dowels (wooden connecting pegs) in parts such as drawers or shelves. • Multi spindle boring machines (enables more than one hole to be bored at a time) are normally available in sizes of up to 6 feet long. • There may be as many as 20 spindles on large production machines.

  11. Mortising and Tenoning • Mortise and tenon joints, with one piece chiseled to fit into a slot cut into a slot in another, are the mark of fine furniture (fig 21-24, page 319). • Most furniture joints are secured with screws, dowels, or biscuits (flat discs). • Screws provide the weakest joint, and dowels create a loose joint through expansion and contraction.

  12. Summary • There are 9 major types of processes used in manufacturing wood products: planing, jointing, shaping, routing, turning, sawing, drilling, boring, and mortising and tenoning. • Planing or surfacing is a process that mills wood to a uniform thickness and produces a smooth surface. • Shaper is used for producing intricate shapes required for molding or window framing. • Machine drilling, or boring, of holes in wood is normally done with a drill press or a boring machine. • Mortise and tenon joints, with one piece chiseled to fit into a slot cut into a slot in another, are the mark of fine furniture.

  13. Home Work • 1. What is planing? • 2. What is a shaper used for? • 3. What are mortise and tenon joints?