MEM05 Metal and Engineering Training Package MEM07005C Perform general machining Learner guide Version 1 Training and Education Support Industry Skills Unit Meadowbank Product code: 5449
Acknowledgments The TAFE NSW Training and Education Support Industry Skills Unit, Meadowbank would like to acknowledge the support and assistance of the following organisations and people in the production of this learner guide. Hare and Forbes Machinery House Fitting and Machining (Ron Culley) Electricity Commission of NSW (Lathe Manual) BHP (Machinist Manual) Blackwoods ISCAR TAFE NSW, Fitting and Machining (Theory Book 2) Writer: Andrew Gill TAFE NSW Reviewers: Mark Pollard (South Western Sydney Institute) Greg Carrol (Western Institute) Project Manager: Stephen Davies Education Programs Manager TAFE NSW Enquiries Enquiries about this and other publications can be made to: Training and Education Support Industry Skills Unit, Meadowbank Meadowbank TAFE Level 3, Building J, See Street, MEADOWBANK NSW 2114 Tel: 02-9942 3200 Fax: 02-9942 3257 The State of New South Wales, Department of Education and Training, TAFE NSW, Training and Education Support Industry Skills Unit, Meadowbank, 2011. Copyright of this material is reserved to TAFE NSW Training and Education Support Industry Skills Unit, Meadowbank. Reproduction or transmittal in whole or in part, other than for the purposes of private study or research, and subject to the provisions of the Copyright Act, is prohibited without the written authority of, TAFE NSW Training and Education Support Industry Skills Unit, Meadowbank ISBN 978-1-74236-242-7 Developed by Training & Education Support Industry Skills Unit, Meadowbank TAFE NSW 2011
Table of Contents Introduction...9 1. General introduction... 9 2. Using this learner guide... 9 3. Prior knowledge and experience... 11 4. Unit of competency overview... 11 5. Assessment... 16 Topic 1: The centre lathe... 21 Introduction and safety... 21 Lathe maintenance... 29 Mounting work in the lathe... 30 Lathe chucks... 30 Mounting a chuck... 32 Holding work in a chuck... 35 Setting up in a four jaw chuck... 36 Types of cutting tools... 37 Cutting tool materials... 40 Setting up the cutting tool... 44 Feed and depth of cut... 48 Types of cutting operations... 50 Lathe centres... 58 Principles of metal cutting... 59 Cutting f uids... 62 Review questions... 66 Topic 2: The milling machine... 69 Types of milling machines... 69 Parts of the vertical mill... 70 Vertical mill controls... 71 Movements of the vertical mill... 73 Movements of the vertical mill head... 74 Developed by Training & Education Support Industry Skills Unit, Meadowbank TAFE NSW 2011
The bed mill... 77 Combination horizontal/vertical mill... 77 Horizontal/universal mill... 77 Milling safety... 79 Mill maintenance... 80 Types of milling cutters... 81 Cutting tools for vertical milling... 82 Selection of milling cutters... 83 Care and maintenance of milling cutters... 83 Mounting milling cutters... 84 Mounting the work piece... 87 Clamping in a vice... 90 Milling in the vice... 92 Milling operations... 93 Conventional and climb milling... 96 Speeds and feeds for milling... 98 Locating the work piece edge...102 Review questions...103 Topic 3: Radial arm drill... 107 Introduction...107 Radial drilling machine types...110 Tool holding devices...111 Work holding...112 Safety precautions...113 Drilling operations...114 Setting up in the radial drill...116 Types of cutting tools...117 Cutting speeds and RPM calculations...124 Review questions...125 Developed by Training & Education Support Industry Skills Unit, Meadowbank TAFE NSW 2011
Topic 4: Surface grinding... 129 Purpose...129 Introduction...129 Machine types...129 Grinder classif cations...130 Surface grinder features...131 Operation of the surface grinder...131 General set-up and installation...133 Dressing and truing...136 Operating procedure...138 Using coolant...139 Maintenance...140 Safety...142 Abrasive wheels...143 Holding work...144 Review questions...150 Job 1: Introduction to the lathe...155 Job 2: Turning to size...161 Job 3: Turn, bore, drill and ream in the lathe...165 Job 4: Introduction to the mill...168 Job 5: Milling to size...172 Job 6: Parallel strip...175 Job 7: Toolmakers Clamp...184 Job 8: Tee Tap Wrench...189 Resource Evaluation Form... 195 Developed by Training & Education Support Industry Skills Unit, Meadowbank TAFE NSW 2011
Topic 1: The centre lathe Introduction and safety The Lathe is a machine tool in which the work can be held and rotated. A cutting tool is held and either moved along or across the work to produce cylindrical shapes (turning) or f at surfaces (facing). The speed at which the work rotates can be varied as can the speed at which the tool travels (feed). This is necessary because of the different diameters and types of materials that have to be turned. There are many and varied types of operations that can be carried out on the lathe eg, threading, boring, drilling, reaming, form turning etc. Workpiece sizes are determined by the largest diameter and length of work which can be accommodated. Lathe safety precautions Like any machine tool the lathe must be operated in a safe manner and the operator must concentrate on what is being done on the machine at all times otherwise serious injury may occur from poor operating procedures. Possible injuries include: burns, cuts, eye injury and possible entanglement. The following points should be observed to prevent possible injury. Wear suitable close f tting clothing. Wear approved eye protection. Use correct lifting methods. Keep tools or jobs from the headstock (moving parts). Use correct tools and equipment. Keep work area tidy. Keep hands away shavings. Clothing torn off the lathe operator and Do not stop the machine with wrapped around the job your hands. Always remove the chuck key from the chuck. Keep your eyes on the machine while it is operating. Switch the power off when setting the job in the lathe. Ensure all locking pins are secured when changing chucks. Beware of sharp tools in the tool post. Page 21 of 198
Lathe dimensions When comparing the size and working capacities of metal lathes there are several key dimensions to consider. They include: Swing over the bed Distance between centres The diameter of the largest work piece that can be rotated on the spindle without hitting the bed. The longest piece of work that can be held between centres. Swing over the carriage Diameter of spindle through hole Centre lathe components Digital readout Chuck guard Head stock Feed box Lead screw Feed screw Swarf tray The diameter of the largest work piece that can rotate over the carriage without hitting it. The diameter of the hole that passes through the spindle. Tool post Top slide Tail stock Carriage Apron Start/stop E stop Cross slide Foot brake Page 22 of 198
Heavily ribbed Vee bed Machine ways 1. Bed Bed J Jaw chuck Headstock Feed gear box Lead screw Feed shaft Tool post The bed is the foundation of the lathe. It is the part that aligns and supports the other parts of the lathe. Made from high quality f ne grain cast iron, it is heavily ribbed to remain distortion free. The top surface of the bed has two Vee's and two f ats, one of each for the Saddle and one of each for the Tailstock (Fig 1) and precision machined to accurately align other parts. The top surface of the bed is called "ways" or "slides". On some lathes they may be hardened to give greater wear resistance. Take care of the bed slide ways as worn or damaged ways cannot provide accurate alignment in the moving parts. Thus poor quality work will result. Cross side Compound side Saddle Froward/Reverse lever Tallstock Figure 1 Figure 2 Page 23 of 198