1. Manufacturing Rounded Shapes ManufacturingProcesses

2. Examples of Lathed Parts

3. Outline Types of Processes Turning Parameters Geometry Material Removal Rate Forces Lathe Components Lathe Attachments Design Considerations Types of Lathes

4. Types of Processes TurningFacing Form Tools BoringDrillingPartingThreadingKnurling

5. Various Turning Operations

6. Turning Operation

7. Turning Parameters Geometry -side rake angle -back rake angle -relief angles -cutting-edge angles -nose radius Forces in Turning -cutting force -thrust force These forces cannot be calculated accurately; they are determined by experiments Material Removal Rate

8. Lathe Tool Parameters

9. Lathe Tools

10. Lathe Tool Inserts

11. Lathe Tool Holders

12. Lathe Feed and Speed V = πDN/12 V = cutting speed in ft/min; Velocity at which the tool head moves along the workpiece surface D = diameter of the rotating tool or rotating workpiece N = RPM of the rotating tool or rotating workpiece Feeds for a lathe are listed as in/rev or m/rev. Multiply these by the RPM to obtain the feed in in/min or m/min.

13. Lathe Feed and Speed Example: Work Material:Aluminum Tool Material:High Speed Steel Workpiece Diameter: 3.375 in Recommended Cutting Speed: 600 ft/min N = 12V/πD N=12*600/(π*3.375) =679.2 RPM The closest available speed on the lathe, without exceeding this value, is 630 RPM so this value should be used. Recommended Feed for HSS/aluminum =.01-.02 in/rev f = (.01-.02)*630 RPM = 6.3-12.4 in/min

14. Material Removal Rate Material Removal Rate (MRR) is the volume of workpiece material removed per unit time MRR = πD avg df N D avg = average diameter =(D original + D final )/2 = (D original - d) d = depth of cut f = feed, in/rev or mm/rev N = RPM

15. Material Removal Rate Example: Original Diameter = 3.375 in RPM = 630 RPM Feed =.01 in/rev Depth of cut =.02 in MRR = πD avg dfN D avg = 3.375 -.02 = 3.355 in MRR = π*3.355*.02*.01*630 = 1.33 in 3 /min

16. Lathe Components BedCarriageHeadstockTailstock -dead center -live center Feed Rod and Lead Screw

17. Lathe Components

18. Example of a Lathe

19. Centers

20. Lathe Attachments ChucksCollets Face Plates MandrelsAccessories

21. Chucks

22. Lathe Attachments

23. Collets

24. Mandrels

25. Design Considerations Design parts so they can be fixtured or clamped easily Design the part so that tolerances of the dimensions and finishes are as large as possible Avoid tapers, sharp corners, and large variations in the dimensions of the part Produce blanks as close to the final design as possible Design the workpiece so that the cutting tools can move across it without obstructions Standard cutting tools should be able to machine the design Select materials that can be machined properly

26. Types of Lathes Tracer Lathes Automatic Lathes Automatic Bar Machines Turret Lathes Computerized Lathes

27. Turret Lathe Operations

28. Turret Lathes and Computerized Lathes

29. Example of a Turret Lathe

30. Vertical Turret Lathe

31. Summary Various processes are available to create different shapes and surface effects Several different fixtures exist to hold a workpiece in a lathe A workable design must be considered in order to allow efficient machining

32. )))))))))))))))))))))))) The End