LATHE MACHINES- defination, types process

Detailed study of Lathe machine

1. LATHE MACHINES Longitudinal Axis Tool Holding Equipment

2. HISTORY The lathe is an ancient tool. The earliest evidence of a lathe dates back to  Anc ient Egypt  around 1300 BC.  There is also tenuous evidence for its existence at a Mycenaean Greek site, dating back as far as the 13th or 14th century BC.

3. I NTRODUCTION 3 The lathe machine was also utilised in Ancient Greece, as we’d now call the two-person model. One workman would turn a wooden workpiece with rope in the lathe frame, and another would shape the material with a sharp tool. The lathe is a simple device that rotates a piece of metal, wood, or stone to create a uniformly curved edge. In addition to cutting and grinding, the lathe can be used in sanding, facing, and knurling. While we use a mechanical lathe today, people used simplified versions of the lathe as far back as ancient Egypt.

4. Components 20XX Pitch Deck 4

5. FUNCTIONS Cutting 5 Sanding Turning Facing Drilling  Knurling Deformation T hreading

6. CLASSIFICATION 6

7. S p eed Lathe Machine A Speed Lathe Machine is a high-speed, hand-operated lathe machine, mainly used by woodworkers. It can provide a spindle speed from 1200 to 3600rpm. Due to their high-speed spindle, speed lathe machines are used for woodturning, furniture making, metal polishing, spinning, and centring .

8. E n g ine Lathe Machine 8 Engine  Lathe Machine  is the most popular type of lathe machine. Nowadays the machine is driven by an electric motor but back in the 19 th century people used steam engines to drive the machine. That’s why it is called an engine lathe machine. This type of lathe machine is used for woodworking and metalworking. T he machine is capable of handling workpieces up to 1 meter in diameter, and up to 4 meters in length.

9. Production Lathe Machine 9 A lathe is a machine tool that rotates a workpiece about an axis of rotation to perform various operations, with tools applied to the workpiece to create an object with symmetry about that axis. A lathe consists of four main parts: the bed, spindle, turret, and tailstock . Briefly, the main spindle holds the material and rotates it. The turret, where the tool is attached, moves to shape the part to be machined. The tailstock supports the long workpiece.

10. Automatic Lathe Machine 10 An automatic Lathe machine has a group of mechanisms that makes it capable of automatically changing and feeding cutting tools. When you have a complicated precision operations job, that requires skills, you have to produce it in mass quantity. This machine is suitable. This machine is heavy-duty, production-friendly, and expensive.

11. Special Purpose Lathe Machine 11 As the name implies that these types of lathe machines used for special purpose and production work. In this lathe only special operations are performed such as Drilling, Grinding Reaming, Boring etc. can be done.

12. Numerical Control Lathe Machine 12 CNC Lathe Machines are the most up-to-date lathe machines in terms of technology. They come with a modern computer numeric control system (CNC). You can use this control system to add a CAD/CAM program and after that, whenever you command the machine, it will start and perform the machining operation according to your program input.

13. 13 S PECIFICATION Height of centre from the lathe bed – 125 mm Distance between two centres – 500 mm Largest Diameter of bar – 200mm to 1600mm Length of Bed - 7' to 24'

14. COMPONENTS & Functions 14 Headstock : The headstock is found at the end of the bed. Once clamped to the end, the headstock provides the rotational power for the lathe's operations. Bed : The bed is a large horizontal structure or beam that supports other parts of a lathe like the headstock and tailstock. Except woodworking lathes, nearly all lathes have a bed. It's the long platform on which these parts are mounted.

15. 15 Tailstock : Located opposite the headstock on a CNC machine lathe, tailstocks are used to secure and support the free end of a workpiece while it is being machined. A tailstock ensures that the work piece's longitudinal rotary axis is held steady and precisely parallel to the lathe bed. Carriage : The carriage is the part of the lathe which slides over the bed-ways between the headstock and the tailstock. It provides various movements for the cutting tool manually as well as by power feed.

16. Feed Mechanism : The feed mechanism is the combination of different units through which motion of headstock spindle is transmitted to the carriage of the lathe machine. Following units play role in the feed mechanism of a lathe machine: End of bed gearing, Feed gear box, Lead screw and feed rod. Screw Cutting Mechanism :  A screw-cutting lathe is a machine (specifically, a lathe) capable of cutting very accurate screw threads via single-point screw-cutting, which is the process of guiding the linear motion of the tool bit in a precisely known ratio to the rotating motion of the workpiece. 16

17. 17 Classification of Carriage

18. L athe Accessories 18

19. Classification of chucks 19 Three Jaw Chuck : A three-jaw chuck is a versatile clamping device commonly used in metal, wood, or plastic turning operations on a lathe machine, as well as CNC milling and drill pressing operations. Four Jaw Chuck : Four jaw lathe chucks are a particular type of chuck designed to safely and securely hold square, hexagonal, wound, and irregular-shaped workpieces. T he 4-jaw chuck's jaw control allows for finer adjustments and improved accuracy .

20. 20 Combination Chuck : A chuck with jaws that may be moved simultaneously or independently. Magnetic Chuck : Magnetic Chucks are an alternative to traditional workholding machinery, as they use magnetic force from permanent magnets to clamp and secure workpieces in place.

21. 21 Air or Hydraulic-operated Chuck : The hydraulic chuck uses liquid as the working medium and uses the pressure energy of the liquid to transmit power; the pneumatic chuck uses compressed air as the power source to drive the machine to expand or rotate. Drill Chuck : Drill chucks are devices used to hold a drill or other cutting tools on a spindle. They are available in keyed, keyless or hybrid systems, allowing for quick changes of a drill bit.

22. 22 Types of Lathe Centre Ordinary Centre : A lathe centre , often shortened to centre , is a tool that has been ground to a point to accurately position a workpiece on an axis. They usually have an included angle of 60°, but in heavy machining situations, an angle of 75° is used. Ball Centre : The ball centre is employed for taper turning with a tail-stock set-over method to minimize wear and strain on centres .

23. 23 Frictionless Centre : The frictionless centre boasts the capability to withstand high-applied forces while allowing rotation along with the workpiece. Its ability to operate at very high speeds makes it ideal for demanding machining applications. Half Centre : A half- centre  enables one to face the whole part when one is turning between centres but should be replaced when one is through with the facing operation.

24. 24 Tipped Centre : The primary use of a center is to ensure concentric work is produced; this allows the workpiece to be transferred between machining (or inspection) operations without any loss of accuracy. Insert Centre : Inserts are used as the cutting edges for cutting tools such as tool holders for turning and face milling cutting for milling.

25. Pipe Centre : Pipe centres are a measurement which explains what the exact distance between your two radiator pipes will have to be to correctly install the home radiator you select.

26. 26 catch plate and carriers Catch plates and carriers play a vital role in driving workpieces when they are held between two centres on a lathe. Carriers are essentially driving dogs that attach to the end of the workpiece using a setscrew, while catch plates are bolted to the nose of the lathe's headstock spindle.

27. 27 face plate A faceplate is a circular metal plate used for holding workpieces in a lathe. When the workpiece is clamped to the faceplate of the lathe, turning can begin. A workpiece may be bolted or screwed to a faceplate, a large, flat disk that mounts to the spindle.

28. 28 angle plate An angle plate is a work-holding device used as a fixture in metalworking. Angle plates are used to hold workpieces square to the table during marking-out operations. Adjustable angle plates are also available for workpieces that need to be inclined, usually towards a milling cutter.

29. 29 Types of lathe mandrel Plain Mandrel : The body of the plain mandrel is slightly tapered to provide proper gripping of the workpiece. It is also known as solid mandrel. It is the type mostly commonly used and has wide applications. Step Mandrel : Stepped mandrels are  used for collars, washers, odd-sized jobs and so on . The stepped mandrel will have steps of different diameters to accommodate different workpieces.

30. 30 Collar Mandrel : The collar mandrel is basically a lighter plain mandrel with two fixed collars attached at both ends. The fixed collars fit firmly on the workpiece. Generally, this mandrel is used for holding workpieces with diameters above 100 mm. Screwed Mandrel : It is threaded at one end and a collar is attached to it. Workpieces having internal threads are screwed on to it against the collar for machining.

31. 31 Cone Mandrel : It consists of a solid cone attached to one end of the body and a sliding cone, which can be adjusted by turning a nut at the threaded end. This type is suitable for driving workpieces having different hole diameters. Gang Mandrel : It has a fixed collar at one end and a movable collar at the threaded end. This mandrel is used to hold a set of hollow workpieces between the two collars by tightening the nut.

32. 32 Expansion Mandrel : Expanding mandrels on a lathe are a type of mandrel that grip the interior diameter or ID of a workpiece. On an expanding mandrel, the shaft and sleeve have corresponding tapers and are machined from hardened steel. The sleeve is slotted and expands when pressed into the tapered shaft.

33. 33 Different Rests of Lathe Machine Centre Rest : The primary purpose of a lathe steady rest is to support and stabilize long and slender workpieces while they are being turned or machined. In most cases, you never have to replace the steady rest and just have to replace the screws and the bearings.

34. 34 Follower Rest : The purpose of the follower rest is to keep long or small-diameter work from deflecting when a cutting tool is applied to it. It is attached to the lathe saddle and moves as the saddle moves, keeping the point of support directly behind the cutting tool.

35. 35 acknowledgement I would like to express my special thanks of gratitude to my teacher as well as to our principal ma'am who gave me the golden opportunity to do this wonderful project on the topic LATHE MACHINES , which also helped me in doing a lot of Research and I came to know about so many new things..... Harshavardhan Vikramsinh Khot Yashwantrao Chavan Vidyalaya 10 Th

36. Thank You 36