Participant Handbook Machining Technician (Lathe) Participant Handbook 2 Machining Technician (Lathe) Table of Contents Symbols Used in This Manual .................................................................................4 Metrology Unit Conversation ................................................................................................................5 Basic Geometry - 2D ............................................................................................................13 Basic Geometry - 3D ............................................................................................................23 Reading Engineering Drawings .............................................................................................29 Precision Measurement - Vernier Calliper ............................................................................41 Precision Measurement - Micrometer ..................................................................................47 Precision Measurement - Other Instruments........................................................................55 Precision Measurement - Gauges .........................................................................................61 Metallurgy Understanding Materials .....................................................................................................65 Machining Optimisation.......................................................................................................81 Safety PPE ......................................................................................................................................85 Generic Safety .....................................................................................................................91 Conventional Turning Basic Parts and Working Principle ........................................................................................95 Cutting Tool Angles - Single Point Cutting .......................................................................... 101 Outer Diameter (OD) Turning ............................................................................................ 109 Facing ............................................................................................................................... 117 Turning Between Centres .................................................................................................. 123 Taper Turning .................................................................................................................... 129 Drilling .............................................................................................................................. 137 Boring (Simple) ................................................................................................................. 145 Participant Handbook External Grooving ............................................................................................................. 151 Internal Grooving .............................................................................................................. 155 Fundamentals of Thread Cutting in Lathe .......................................................................... 159 External Threading ............................................................................................................ 165 Internal Threading ............................................................................................................ 171 Parting .............................................................................................................................. 177 CNC Turning Introduction to CNC .......................................................................................................... 181 Coordinate Systems - Cartesian ......................................................................................... 187 Control Systems ................................................................................................................ 193 G Codes and M codes ........................................................................................................ 203 Part Program Development ............................................................................................... 211 Throw away Insert Tools ................................................................................................... 223 Mounting of Tool Holders on Turret .................................................................................. 227 Tool Number and Offset Number ...................................................................................... 231 Work Holding .................................................................................................................... 235 Work Piece Setting ............................................................................................................ 239 Fault Tracing Techniques ................................................................................................... 243 Routine Preventive Measures ........................................................................................... 249 Stress Management .......................................................................................................... 253 Work Ethics ....................................................................................................................... 259 Attitude ............................................................................................................................ 265 Communication ................................................................................................................ 271 Participant Handbook Symbols Used in This Manual Symbol Meaning Objectives Theory Procedure Key Learnings Worksheets Notes 4 Machining Technician (Lathe) Unit Conversion At the end of this module you will be able to: T explain measurements terms (length, weight, time, etc.), T explain the different measurement systems; T convert values between the measurement systems. Session Plan 1 Measurements 2 Length 3 Weight 4 Time 5 Different Measuring Unit 6 Unit Conversion 7 Key Learnings 8 Worksheet Measurements Shailesh has just started his apprenticeship as a computer numerical control (CNC) lathe operator. Today is his first day at the site and he is excited to start operating a CNC machine. But, he is left perplexed when his workshop supervisor, Mohan asks him to read up on the different measurement units. With a disappointed look on his face he asks Mohan: Sailesh: Why do I need to know about measurements units? Isn’t my job, simply to operate the machine? Mohan: Well yes, but to complete a task you need to take critical measurements based on dimensions set forth in the Engineering Drawings. In addition to this, you need to implement any needed adjustments. Thus, it is extremely important for you to understand how to measure things. Sailesh: Oh! I see. So, brushing up the measurement units will help me make accurate measurements. Mohan: That’s right! This way you can maintain quality by controlling the work being manufactured to exact tolerances. Let me start by explaining what a measuring unit is. A measurement unit shows the size or amount of something. In order to complete your job you need to know all about the measurements such as width, length, height, weight and time. Measurements In order to measure something you need to assign a number to that entity. For Instance, when I say the scale is 30 centimeter long, I am assigning a number to length of the scale. 30 in this example is the numerical value and centimeter is the unit for measurement. 5 Participant Handbook 30 centimeter No value is complete if we don’t add the unit of measurement along with it. Let us learn more about the units. Length Mohan: The first kind of measurement we are going to explore is length. This is important for lots of different reasons. Measurement of length helps you measure the distance between any two points, or how long and tall things are. Can you recall the most common units of length? Sailesh: Well of course, the most common measurements of length are centimeters, Kilometers, inches, feet, yards and miles. Mohan: That’s absolutely correct Sailesh. Now, tell me what unit of length will you use to measure thickness of this handbook? Sailesh: The thickness of this handbook is quite less so, it would be appropriate to measure it in millimeter or centimeters. Mohan: Bingo! How about when we have to measure the length of a long Ribbon? Sailesh: The length of the Ribbon will be measured in meters. Mohan: Correct Sailesh! Similarly, to measure long distances like the distance between two towns, we use kilometers. 100 centimeters add up to make one meter and once you have 1000 meters you will have one kilometer. Sailesh: I see. Weight Mohan: Next, Let’s talk about Weight. Weight of an object means how heavy the object is. Sailesh: Oh yes! Bigger the size more the weight, right? Mohan: Well, not always Sailesh. The weight of an object does not depend on its size. For instance, a large plastic ball may be lighter than a small ball made of iron. Sailesh: Ahh yes… Of course! But, don’t we always measure weight in Kilograms? Mohan: Well, Kilograms is one of the common measurements of weight, but we use grams to weigh lighter things. For instance, hold one small paperclip in your hand. Does it weigh a lot? No! A gram is very light. That is why you often see things measured in hundreds of grams. Once you have 1,000