1. Chapter 7 Technological Systems and Production Tools in Technology

2. Production Tools • Change the shape of materials to make them useful for human needs • Help in the creation of artifacts. Objects made by human activity. • Are created and maintained by humans • Are used to make our lives easier • Social problems can be created by tools???

3. Material Processing • Tools and Machines • Changes the form of materials • Tools were used to cast, form, and machine materials into specific shapes • Tools also can be used to help assemble products and apply protective or decorative coatings

4. Machine Tools • Machines used to make other machines. • The elements of machine tools include • What type of tool is it??? • Single or Multiple Point Cutting Tool • What type of cutting motion is implemented??? • Rotating, Reciprocating, or Linear • What type of support is used to machine the stock???

5. Cutting Tools • Cutting actions require a cutting tool • Cutting tools must be harder than the material being cut • Needs sharpened edges, relief angles, and rake angles • Sharpened edges cut the material • Relief angles keep the tool sides from rubbing against the material • Rake angles create a chip which allows waste materials to be carried away

6. Types of Cutting Tools • Single Point Cutting Tools • Contains a cutting edge on the end or along the edge of a rod, bar, or strip • Examples: • Chisels • Hand Planes • Knives

7. Types of Cutting Tools (cont.) • Multiple Point Cutting Tools • Series of single point tools arranged on a cutting device. • Can be arranged in a set or random pattern • Examples: • Saw teeth are in a set pattern • Abrasive paper and grinding wheels do not contain a set cutting arrangement

8. Motion • Cutting Motion • The action that causes material to be removed from the work • Feed Motion • The action that brings new material into the cutter • To complete a cut both motions need to happen simultaneously

9. Motion (Cont.) • Cutting and feed motions can be: • Rotating: Uses round cutters or spins the work around an axis • Linear: Moves the cutter or work in one direction along a straight line • Reciprocating: Moves the tool or work back and forth or up and down.

10. Support • The tool and work piece must be supported for proper operation. • Types of cutting and feed motions determine the type of support needed. • Rotating motions: Require a holder that will revolve around an axis. • Reciprocating motions: The blade is clamped at two ends within the machine. The blade moves back and forth or up and down and cuts on one movement of the saw blade. • Linear motions: Lathes use tools that are clamped in a holder or held on rest. Band Saw blades travel around two wheels while the material is supported by the machine table.

11. Support (Cont.) • Reciprocating motions: The blade is clamped at two ends within the machine. The blade moves back and forth or up and down and cuts on one movement of the saw blade. • Linear motions: Lathes use tools that are clamped in a holder or held on rest. Band Saw blades travel around two wheels while the material is supported by the machine table.

12. Six Categories of Machine Tools • Turning Machines • Sawing Machines • Drilling Machines • Shaping Machines • Planing Machines • Grinding Machines

13. Turning Machines • Turning: Process in which a workpiece is held and rotated on an axis. • This process is completed on machines called lathes. • Lathes produce their cutting motion by rotating the workpiece. • The feed motion is generated by linear movement of the tool.

14. Lathe • Precise machine tools used to machine wood, metal, and plastics. • Contain four main parts: • Headstock: Contains the machine’s power unit. • Tailstock: Supports the opposite end of a part that is gripped at the headstock. • The headstock and tailstock are attached to the bed of the lathe

15. Lathe (Cont.) • Tool rest or holder: Support the tool. On metal lathes the tool rest is clamped into position and is fed into or along the work. Wood lathes contain a flat tool rest where the operator moves the tool by hand. • Work can be held or clamped into place in two ways. • Between centers • Live Center: Rotate with the workpiece • Dead Center: Work rotates around the device • Within the headstock

16. Lathe Operations • Turning: Cutting along the length of the workpiece. • Tapering: Cutting along the length of a cylinder at a slight angle to produce a cylindrical shape with a uniformly decreasing diameter. • Facing: Cutting across the end of a rotating workpiece to produce a square end. • Grooving: Cutting into a workpiece to produce a channel with a diameter less than the main diameter of the workpiece.

17. Lathe Operations (Cont.) • Chamfering: Cutting an angled surface between two diameters on the workpiece. • Parting: Cutting off a part from the main workpiece. • Threading: Cutting threads along the outside diameter or inside a hole in the workpiece. • Knurling: Producing a diamond pattern of grooves on the outside diameter. This produces a gripping surface.

18. Sawing Machines • Use teeth on a blade to cut material to a desired shape and size. • Three basic groups of saws include: • Circular Saws • Band Saws • Scroll Saws

19. Sawing Machine Cutting Operations • Crosscutting: Reducing the length of a material • Ripping: Reducing the width of material • Resawing: Reducing the thickness of material • Grooving, Dado, Notching: Cutting rectangular slots on or across a part • Chamfering and Beveling: Cutting an angled surface between two primary surfaces of a material.

20. Circular Saws • Use a disk shaped blade with teeth arranged around an edge. • Three types of circular saws: • Table Saw • Radial Saw • Chop Saw

21. Table Saw • Uses a linear feed motion • Workpiece is pushed into the rotating blade. • The operator controls the rate of speed that the workpiece runs through at.

22. Radial Saw • The rotating blade moves across the workpiece • The workpiece is positioned stationary on the saw table bed

23. Chop Saw • Used to cut narrow strips of material to length • The blade is attached to a pivot arm assembly • The blade assembly is pivoted in a downward motion to produce the cut • Can create angled cuts • The sliding compound miter saw was created of the chop saw and the radial saw.

24. Band Saw • Uses a blade made from a continuous band or strip • The saw uses a continuous linear motion which generally travels around two wheels to perform a cut • Come in two styles: • Vertical • Horizontal

25. Scroll Saw • Uses a straight blade with teeth on one edge • The blade is clamped or pinned into the machine at one or most commonly at two ends. • This machine operates off the reciprocating motion.

26. Drilling Machines • Drilling: produces or enlarges holes using a rotating cutter. • The drill is moved into the work with a feed arm. This is the feed motion. • The rotating cutter head produces the cutting motion. • Two common types: • Stationary • Portable electric

27. Drilling Operations • Drilling: Producing straight cylindrical holes in a material • Counterboring: Producing two holes around the same center point. The outer hole has a larger diameter than the inner hole. • Countersinking: Producing a beveled outer portion of a hole. • Reaming: Enlarging the diameter of an existing hole.

28. Common Drilling Tools • Twist Drills: shafts of steel with flutes along the shaft and points on the end to produce a chip • Spade Bits: Flat cutters on the end of a shaft • Forstner Bits: Two lipped cutters that produce a flat bottom hole. The are used for counterboring operations in woodworking.