Manufacturing Techniques: Lathe and Milling Machine Operations

1. Manufacturing Techniques Resource 2 Machining Operations & Techniques

2. Aims • Set up a Centre Lathe for a manufacturing process • Set up a Milling Machine for a manufacturing process • Use conventional manufacturing techniques to produce components

3. Objectives • Set cutting tool to perform manufacturing operations • Perform basic machining techniques using a Centre Lathe • Perform basic machining techniques using a Milling Machine • Various work holding devices used to support components • Drilling using a tailstock • Produce internal & external threads using hand tools

4. Turning Operations

5. Types of machining process using Centre Lathe • Facing • Turning a diameter to length • Knurling • Centre drilling/drilling/reaming/internal & external threads • Boring • Chamfering

6. Work holding devices 4 jaw chuck 3 jaw chuck The 4 jaw chuck can be used to hold a variety of components. Each jaw must be individually tightened and centred using a DTI clock The 3 jaw chuck is the most commonly used work holding device on a lathe. Holds round & hexagonal shaped work pieces. Revolving centre Face plate The face plate is attached to the lathe spindle. Work pieces are clamped to the face plate using t-nuts in the slots The revolving centre is used to machine components between centres using the tailstock.

7. Setting tool to centre The tool is positioned in the tool post & adjusted to centre height using packing strips. The packing strips are placed underneath the tool as shown in fig. 1. The centre is obtained by positioning a dead centre in the tailstock. Fig 1 Fig 2

8. Types of machining process using Centre Lathe A knurling tool moves across the side of the component producing a hatch pattern with a required force applied onto the work piece. A single point knife tool moves along the side of the material removing a depth of material & producing various features like tapers & steps. A single point knife tool moves across the face of the component removing a small amount of material to produce a smooth flat surface.

9. Types of machining process using Centre Lathe The face plate is attached to the lathe spindle. Work pieces are clamped to the face plate using t-nuts in the slots Drilling on a Lathe can be performed using the tailstock. The Jacob's chuck is locked in the tailstock with the drill pieces secured in the chuck using a chuck key. A chamfer tool moves into the work piece, to a required depth, producing a chamfered edge

10. Milling Operations

11. Work holding devices Swivel Base Vice Machine Vice Clamping directly to the table V block

12. How to Set a cutting tool The cutting tool is positioned in the appropriate tool holding device and locked in the spindle using a draw bar.

13. Types of machining process using a milling machine • Blocking out • Facing • Slot cutting • Drilling • T-slot cutting

14. Blocking out procedure This process involves machining all 6 faces on a block of material.

15. Milling processes

16. Taps & Dies

17. Taps & Dies Cutting internal threads Internal threads are produced using the correct size tapping drill and tapping sequence. The tap wrench is rotated clockwise to feed the tap into the hole & should be relieved by half a turn every full thread. Cutting external threads External threads are produced using a die & die stock. The external diameter of the material must equal the external thread required. The die stock is rotated clockwise & should be relieved by half a turn every full thread.