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LATHE MACHINE OPERATIONS MODULE GUIDE Module was designed for students’ trainees who wants to have knowledge Training Module MODULE MODULE...
LATHE MACHINE OPERATIONS MODULE GUIDE Module was designed for students’ trainees who wants to have knowledge Training Module MODULE MODULE Lathe Machine Operations T a b l e of C o n t e n t s Module 1 What is the module about? Page Module I: Introduction to Lathe Machine Install domestic refrigeration and air conditioning (DOMRAC) units…............................................................... 2 What did you know about this module?………………………. 4 Domestic refrigeration and air conditioning safety standard................................................................................ 5 Personal protective equipment PPE....................................8 Installation of domestic refrigeration and air conditioning electrical circuit.................................................................... 9 Written Test 1...................................................................... 13 Activity 1.............................................................................. 14 Rubrics................................................................................ 15 What did you learn in this module?.................................... 17 Installation DOMRAC unit................................................... 18 Written Test......................................................................... 25 Activity 2.................................................................................. 26 Definition of terms............................................................... 28 Answer key......................................................................... 29 Module II: Lathe Machine Setup Service and maintain domestic refrigeration and air- conditioning (DomRac) units……………………………………… 31 What did you know about this module ………………………………………………………………………… 33 Clean and replace air filter …………………………….. 34 MODULE LATHE MACHINE OPERATIONS Types of air filter in domestic ref and air con … Service evaporator/ condenser ……………………………………. 47 Types of evaporator and condenser ………….. 48 Maintain fan motor assembly ………………………….. 49 Types of air conditioning fan motor …………… 65 Service electrical power and control circuits …………. 68 Types of electrical and control circuit in domestic refrigeration and air conditioning ….. 81 Accomplish service and maintenance report ………… 83 Written Test …………………………. 105 Activity …………………………………………………………… 106 107 Rubrics …………………………………………………….. What did you learn in this module? …………………………… 109 Definition of terms ……………………………………………… 110 Answer key ……………………………………………………… 111 Module III: BASIC LATHE MACHINE OPERATIONS What did you know about this module? ……………………… 116 Plan and prepare for troubleshooting and repair …………… 117 Appropriate wiring diagrams ………………………………….. 130 Appropriate materials ………………………………………….. 140 Power supply is checked to ensure compliance with nameplate rating ……………………………………….……….. 154 Identify and repair faults/ troubles …………………………….. 162 Appropriate PPE job requirements ……………………………. 166 Components are tested RAC Code of Practice ……………. 173 Faults/problems with components are diagnosed ………..… 178 RAC Code of Practice Remedial action in problem …….….. 181 Workplace safety guidelines …………………………..……... 183 Report on repair and testing of unit ……………………. 189 MODULE LATHE MACHINE OPERATIONS Written Test 3 ……………………………………………….. 193 Activity …………………………………………………………… 194 Rubrics …………………………………………………………. What did you learn in this module? …………………………… 196 Definition of terms ……………………………………………… 197 Answer key ……………………………………………………… 198 Module IV: Activity Task Title Act 1............................................................................... 201 Rubrics................................................................................... 203 Title Act 2............................................................................... 204 Title Act 3............................................................................... 205 Rubrics................................................................................... 206 Title Act 4............................................................................... 207 Rubrics................................................................................... 208 Title Act. 5.............................................................................. 209 Rubrics.................................................................................... 210 Title Act. 6............................................................................... 211 Rubrics.................................................................................... 212 Title Act. 7............................................................................... 214 Rubrics.................................................................................... 215 Title Act. 8............................................................................... 217 Rubrics.................................................................................... 218 Title Act. 9............................................................................... 220 MODULE MODUL E LATHE MACHINE OPERATIONS Rubrics.................................................................................... 221 Title Act. 10............................................................................. 223 Rubrics.................................................................................... 224 MODULE 1 INTRODUCTION TO LATHE MACHINE MODULE MODULE MODU LATHE MACHINE OPERATIONS LE What is Lathe machine operations module’s all about? This instructional module was designed for those student’s trainees under the course Bachelor of Industrial technology major in mechanical technology. It covers the competencies in lathe machine operations. These competencies are covered and divided in four (4) modules appropriately. Each module also provides you with learning outcomes and attainment of two or more objectives. Addition of definition of key terms and acronym will guide the student to easily understand the module. They can be of great help. Use them fully. Module 1 Introduction to Lathe Machine Definition and Types of Lathe Machines Lathe Machine Parts, Functions and its Components Safety Precaution 2 MODULE LATHE MACHINE OPERATIONS MODULE Learning Objectives At the end of the lessons: the trainees and the student are expected to know and learned: Fundamental definition of a lathe machine, including its primary purpose, key components, and its significance in machining processes. Difference Between Various Types of Lathe Machines Identify Lathe Machine parts, function and its Components Hazards are identified correctly in accordance with OHS (occupational health and safety) procedures. Safety sign and symbol are identified and adhered to in accordance with workplace safety procedure. Proper wearing of PPE is properly observed in accordance with workplace safety procedure. 3 MOULE ULE What did you know about this module? TEST YOURSELF Diagnostic test: Choose and encircle the answer in the given question 1. What is a lathe machine primarily used for? a. Baking c. Sewing b. Painting d. Cutting and shaping metal 2. Which of the following parts holds and rotates the workpiece in a lathe machine? a. Chuck c. Carriage b. Tailstock d. Spindle 3. What is the main function of the tailstock in a lathe machine? a. Holds cutting tools b. Supports the workpiece from the other end c. Rotates the workpiece d. Controls the speed of the lathe 4. In a lathe machine, what is the purpose of the carriage? a. Holds the workpiece b. Holds the cutting tool and moves it longitudinally c. Holds the chuck d. Holds the tailstock 5. What is the tool used in a lathe machine to remove material from the workpiece? a. Cutter b. Grinder c. Lathe tool bit d. Welder 4 LATHE MACINE OPERATION MODULE 6. Which of the following is a safety precaution when operating a lathe machine? a. Remove safety guards for better visibility b. Wear loose clothing and jewelry c. Tie back long hair and secure loose clothing d. Ignore the emergency stop button 7. What is the function of the cross slide in a lathe machine? a. Moves the workpiece longitudinally b. Moves the tool perpendicular to the workpiece axis c. Rotates the workpiece d. Holds the chuck 8. What should you do if you notice any unusual sounds or vibrations coming from the lathe machine during operation? a. Ignore it, it will go away b. Increase the speed to see if it stops c. Stop the machine immediately and investigate the cause d. Ask a colleague to check it for you 9. What type of clothing is appropriate for operating a lathe machine? a. Loose-fitting clothes and jewelry b. Tight-fitting clothes and closed-toe shoes c. Shorts and flip-flops d. Lab coat and sandals 10. Why is it important to wear safety goggles or a face shield when operating a lathe machine? a. To protect your eyes from flying debris b. To look professional c. To improve vision in dim light d. To keep hair out of your E 5 LATHE MACINE OPERATION Lathe machine A lathe machine is a machine tool which removes the undesired material from a rotating workpiece in the form of chips with the help of a controllable cutting tool which is traversed across the work and can be feed deep into the work. Working Principle of Lathe Machine The function of a lathe is to remove metal from a piece of work to give it a desired shape and size. In a lathe machine, the workpiece rotates against the tool. The tool is used to remove material from the workpiece. The direction of the motion of the tool is called a feed. 6 LATHE MACINE OPERATION Speed Lathe Machine Image Credit: IndiaMart 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. The machine comes with a very simple design, it contains headstock, bed, tailstock, and tool post. Due to their high-speed spindle, speed lathe machines are used for woodturning, furniture making, metal polishing, spinning, and centering. 7 LATHE MACINE OPERATION Center lathe or engine lathe machine Engine lathe machine is the most popular type of lathe machine. You can find it inside any manufacturing workshop. Nowadays the machine is driven by an electric motor but back in the 19th-century people used steam engines to drive the machine. That’s why it is called an engine lathe machine even it does contain an engine nowadays. It is also called center lathe machine, because back then almost all machine tools were driven by either separate engines or central engines. This type of lathe machine is used for woodworking and metalworking. You can perform various machining operations on this lathe machine… such as turning, facing, grooving, knurling, threading, drilling, boring, reaming, and many more. And lastly, the machine is capable of handling workpieces up to 1 meter in diameter, and up to 4 meters in length. 8 LATHE MACINE OPERATION Turret Lathe Machine Image Credit: IndiaMart A turret lathe machine is an advanced lathe machine used for mass production. It is kind of an upgraded version of an engine lathe, where the tailstock is replaced by a revolving hexagonal turret. In this turret, you can set up multiple cutting tools (usually up to 6 tools), such as drilling, countersinking, reaming, tapping, etc. You see, this design makes your work a lot easier, all you have to do is simply clamp your workpiece in the chuck, perform the first operation, now rotate the turret, and perform the second operation. You can repeat the process as long as you want. 9 LATHE MACINE OPERATION Toolroom Lathe Machine https://machineryexchange.net/cdn/shop/products/GaneshGHT618EVS_1200x.jpg?v =1680299464 This is a special breed of lathe machine mostly used to make precision parts and tools such as die, gauges, jigs, and fixtures. It looks similar to an engine lathe machine. But it is made from more accurate and precise parts than an engine lathe machine. Thus, the price of a toolroom machine is higher than an engine lathe machine. 10 LATHE MACINE OPERATION Bench Lathe Machine Image Credit: Amazon.in A bench lathe machine is a small-size, hand-operated power lathe, mainly used for small precision work. It looks very similar to speed lathe machines. If you have a light job that requires lathe machine operations such as turning, facing, grooving, parting, threading, drilling, boring, knurling, and tapping, this machine is for you. But in general, jewelers and watchmakers use this machine a lot for their machining needs. 11 LATHE MACINE OPERATION Automatic Lathe Machine Image Credit: IndiaMart An automatic Lathe machine comes with a group of mechanisms that makes it capable of changing and feeding cutting tools automatically. When you have a job that is complicated precision operations, requires skills, and you have to produce it in mass quantity… this machine is suitable. This machine is heavy-duty, production-friendly, and expensive. 12 LATHE MACINE OPERATION Special Purpose Lathe Machine Special purpose lathe machines are designed and built for specific, specialized machining tasks. Unlike general-purpose lathes, which are versatile and can handle a variety of operations, special purpose lathes are tailored for particular applications that require unique configurations or capabilities. These machines are engineered to optimize efficiency, precision, and productivity for specific tasks. Here are a few examples of special purpose lathe machines: 13 LATHE MACINE OPERATION CNC Lathe Machine Image Credit: Macpower CNC 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. 14 LATHE MACINE OPERATION Main Parts of Lathe Machine Compound rest Tool post Spindle Headstock Chuck Tailstock Apron Guideways Carriage Feed selector Saddle Bed Cross slide Feed rod Chip pan Hand wheel Lead screw 15 LATHE MACINE OPERATION 1.Headstock It is present on the left-hand side of the lathe. It holds the gear train, main spindle, chuck, gear speed control levers, and feed controllers. It is aligned with the tailstock. The headstock is made up of cast iron. 16 LATHE MACINE OPERATION 1.1 Chuck It is that part of the lathe machine which is used to hold the workpiece. It is attached to the main spindle of the headstock. It rotates with the spindle and also rotates the workpiece. In the lathe machine, we generally use three-jaw (a) or four-jaw check(b). The three jaws of the three-jaw chuck are made to move simultaneously but the jaws of the four-jaw chuck move independently. a. 3 Jaw Chuck b. 4 Jaw Chuck 17 LATHE MACINE OPERATION 1.2 Main Spindle This part of the lathe machine is used to hold cylindrical work piece within it. It is a hollow shaft on which the chuck is mounted. The primary function of the spindle is to rotate the workpiece. This rotation allows cutting tools to be applied to the workpiece, shaping it according to the desired specifications. The rotational speed and direction of the spindle can be controlled, allowing for various machining operations. 18 LATHE MACINE OPERATION 1.3 Feed Selector It is used to select the direction of the feed i.e., whether we want to move the tool from left to right or right to left. Feed selector is present on the headstock Tailstock It is present at the right-hand side of the lathe. It is used to provide supports to the workpiece. It supports the workpiece from one end. 19 LATHE MACINE OPERATION 3. Bed It is the main part of the lathe. All the parts of the lathe are bolted on the bed. It comprises of headstock, tailstock, carriage guideways and other parts. It is made of cast iron. 3.1 Guideways Guideways are present on the bed. As its name indicates it is used to guide the tailstock and carriage. The tailstock and carriage slide over the guideways. It is an inverted V. 20 LATHE MACINE OPERATION 4. Carriage The carriage is present in between the headstock and tailstock. It carries apron, saddle, compound rest, cross slide and tool post. 4.1 Tool Post: It is used to hold the tool. It has T-slot for holding the tool. The tool post is bolted on the carriage. 21 LATHE MACINE OPERATION 4.2 Compound Rest: It is used to set the tool at a desired angle for taper turning and other operations. 4.3 Cross Slide: The cross slide is used to move the tool perpendicular to the axis of the lathe. 22 LATHE MACINE OPERATION 4.4 Saddle: The top portion of the carriage is called the saddle. Cross slide is mounted on the saddle. 4.5 Apron: The front portion of the carriage is called apron. It contains all the moving and control mechanism of the carriage. 23 LATHE MACINE OPERATION 5. Lead Screw The lead screw is used to move the carriage automatically during threading. 6. Feed Rod; It is used to move the carriage from left to right and vice versa. 24 LATHE MACINE OPERATION 7. Chip Pan; Chip pan is used to collect the chips that are produced during the lathe operation. It is present at the bottom of the lathe. 8. Hand Wheel; It is the wheel that is operated by hand to move the cross slide, carriage, tailstock and other parts that have handwheel. 25 LATHE MACINE OPERATION General Machine shop health hazards and Safety prevention Machine shops can pose various health hazards to workers due to the nature of the work and the equipment used. It's crucial for employers and employees to be aware of these hazards and take appropriate safety measures to prevent accidents and health issues. Here are some common health hazards and their prevention in a machine shop: Noise Pollution: Hazard: Continuous exposure to loud machinery and tools can cause hearing damage and loss over time. Prevention: Use ear protection such as earmuffs or earplugs. Implement engineering controls like noise barriers or soundproofing. Airborne Particles and Dust: Hazard: Fine metal particles and dust from machining operations can be inhaled, leading to respiratory issues, lung diseases, and metal fume fever. Prevention: Wear appropriate respiratory protection, use local exhaust ventilation systems, and keep the workspace well-ventilated. Regularly clean and maintain dust collection systems. Chemical Exposure: Hazard: Exposure to solvents, lubricants, cutting fluids, and cleaning agents can cause skin irritation, respiratory problems, or chronic health issues. Prevention: Use gloves, goggles, and appropriate personal protective equipment (PPE) to minimize skin contact. Work in well-ventilated areas, and use fume hoods and exhaust systems when handling chemicals. 26 LATHE MACINE OPERATION Vibration: Hazard: Prolonged exposure to hand-arm or whole-body vibrations from machinery can cause musculoskeletal disorders and circulation problems. Prevention: Use anti-vibration gloves, tools with ergonomic handles, and maintain machinery to minimize vibration. Rotate tasks to reduce continuous exposure. Mechanical Injuries: Hazard: Accidents such as cuts, burns, crush injuries, and amputations can occur due to moving machine parts, sharp tools, and hot surfaces. Prevention: Implement machine guarding, provide safety training, wear appropriate personal protective equipment (PPE) like gloves and safety goggles, and follow lockout/tagout procedures when maintaining machines. Thermal Stress: Hazard: Exposure to extreme temperatures from hot machinery surfaces or welding processes can cause burns and heat stress. Prevention: Wear appropriate heat-resistant clothing, use thermal barriers, and provide regular breaks in cool, shaded areas for workers exposed to heat. Ergonomic Strain: Hazard: Awkward postures and repetitive movements can lead to musculoskeletal disorders, back pain, and strain injuries. Prevention: Provide ergonomically designed workstations, tools, and chairs. Train workers in proper lifting techniques and encourage regular breaks and stretches. 27 LATHE MACINE OPERATION Electrical Hazards: Hazard: Improper handling of electrical equipment can lead to electric shocks and burns. Prevention: Ensure proper grounding and insulation of electrical equipment. Provide training on electrical safety and use appropriate electrical safety devices. Regular safety training, proper use of personal protective equipment, and strict adherence to safety protocols are essential in mitigating these health hazards in a machine shop. Regular safety audits and involvement of employees in safety programs also contribute significantly to a safer work environment. 28 LATHE MACINE OPERATION Personal Protective Equipment (PPE) Refers to protective safety goggles, safety gloves, safety shoes, dust mask, working apron. The hazard addressed by protective equipment include physical, electrical, chemicals, biohazards. Lathe Machine Operator (PPE) Safety shoes - Protect from Falling & Flying Objects. Safety Googles - can prevent foreign objects or debris from damaging your vision. Dangerous particles or chemicals could be floating around in your workplace. Working apron – is made chrome leather and provide aircon technician with complete protection of his chest to mid-calf from oil, refrigerant and grease. Dust mask – When working as a lathe operator, it is essential to protect yourself from airborne particles and dust, which can be harmful if inhaled. 29 LATHE MACINE OPERATION Safety Tips in Lathe machine Lathe machines are powerful tools that can be used to create a wide variety of products, but they can also be dangerous if not used properly. Here are some general safety tips for lathe machine operations: Wear appropriate personal protective equipment (PPE). This includes safety glasses, a hard hat, closed-toe shoes, and an apron. Inspect the lathe before using it. Make sure that all guards are in place and that all moving parts are working properly. Secure the workpiece properly. Use a chuck, collet, or other work holding device to ensure that the workpiece does not move during machining. Use the correct cutting tool for the job. Make sure that the tool is sharp and in good condition. Start the lathe at a slow speed and gradually increase the speed until you reach the desired RPM. Never leave the lathe unattended while it is running. Stop the lathe completely before making any adjustments. Use a brush or compressed air to remove chips and coolant from the lathe. Do not use your hands. Be aware of your surroundings. Keep your hands away from rotating parts and flying chips. 30 LATHE MACINE OPERATION Here are some additional safety tips: Tie back long hair and remove loose clothing and jewelry. These items can get caught in the lathe's moving parts. Do not operate the lathe under the influence of alcohol or drugs. Be familiar with the lathe's controls and emergency stop button. If you are new to lathe operation, get training from a qualified person. By following these safety tips, you can help to prevent accidents and injuries while operating a lathe machine. 31 MODULE LATHE MACHINE OPERATIONS MODULE Name: Date: Written Test Directions: Choose the correct answer for each question. 1. What is the primary function of a lathe machine in metalworking? A. Drilling holes B. Shaping and cutting metal C. Welding metals together D. Polishing surfaces 2. Which of the following materials can be machined using a lathe machine? A. Wood and plastic B. Metal and wood C. Glass and ceramics D. Rubber and fabric 3. What is the purpose of the chuck in a lathe machine? A. Holds and rotates the workpiece B. Holds cutting tools C. Provides power to the machine D. Measures the dimensions of the workpiece 4. What is the spindle in a lathe machine responsible for? A. Holding the workpiece B. Rotating the workpiece or cutting tool C. Guiding the cutting tool D. Controlling the machine's speed 5. Which part of the lathe machine allows for the adjustment of cutting tools and tool holders? A. Tailstock B. Tool post C. Chuck D. Cross-slide 6. What is the main purpose of a lathe machine's apron? A. Holds the workpiece securely B. Houses the gears for thread cutting C. Supports the tool post D. Provides stability to the machine 7. Which of the following is a safety precaution when operating a lathe machine? A. Loose clothing and long hair should be left hanging freely B. Keep the work area cluttered for easy access to tools C. Always wear appropriate personal protective equipment (PPE) D. Ignore warning signs and labels on the machine 32 MODULE LATHE MACHINE OPERATIONS MODULE Name: Date: 8. Why is it important to wear safety goggles when operating a lathe machine? A. To protect against dust B. To prevent eye injuries from flying chips and coolant C. To improve vision D. To shield against loud noises 9. What should be done in the event of a power outage or sudden machine malfunction during operation? A. Increase the machine speed B. Restart the machine immediately C. Wait for the machine to automatically fix the issue D. Follow proper shutdown procedures and inform a supervisor 10. What is the significance of regular maintenance in lathe machine safety? A. It prevents wear and tear of the machine B. It ensures the machine operates at maximum speed C. It reduces the need for safety precautions D. It ensures the safe and efficient operation of the machine Checked by: 33 MODULE LATHE MACHINE OPERATIONS MODULE Name: Date: Activity no.1 Identify the activities of the job, the hazards, body part, and the personal protective equipment needed to address the hazards. You can use additional forms if you need more space. Reevaluate whenever there are changes to the equipment, processes, or chemicals task Hazard Body part PPE 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Checked by: 34 MODULE MODULE LATHE MACHINE OPERATIONS Republic of the Philippines UNIVERSITY OF RIZAL SYSTEM – Morong Morong Rizal COMPETENCY BASED MODULE IN LATHE MACHINE OPERATIONS RUBRICS IN EVERY ACTIVITIES Total points in Rubrics per Activities Total points Verbal Interpretation 9 - 10 Very - Much Competent 7 - 8 Much Competent 5 - 6 Competent 3 - 4 Slightly Competent 1 - 2 Not Competent RUBRICS IN ACTIVITIES SCORE CRITERIA EXPLANATION The students performed deep Work and explanation go above 10 - 9 understanding of the standard and beyond what is expected and ability to explain the proper use of PPE at the highest level Meet the learning objective Deep understanding The students performed deep Works is correct and contain 8 - 7 understanding of the standard proper use of PPE and ability to explain the proper use of PPE at the perfect level Meet the learning objectives Error free The students performed deep Work is mostly correct but 6 - 5 understanding of the standard contains some error and ability to explain the proper use of PPE at the errors in Almost meet learning objectives reasoning Minimal error The students an emerging the Work contains many errors, but 4 - 3 ability to performed deep is somewhat correct understanding of the standard and ability to explain the proper Farcically understanding use of PPE to the standard Several errors 35 MODULE LATHE MACHINE OPERATIONS MODULE The students performed minimal Work is mostly incorrect 2 - 1 understanding of the standard and ability to explain the proper Minimal Understanding use of PPE to the standard or Frequent Mistakes requires Need help & Hints 36 What did you know about this m What did you know about this module? What did you Learn in this module? TEST YOURSELF Choose and encircle the answer in the given question 1. What is a lathe machine primarily used for? a. Baking c. Sewing b. Painting d. Cutting and shaping metal 2. Which of the following parts holds and rotates the workpiece in a lathe machine? a. Chuck c. Carriage b. Tailstock d. Spindle 3. What is the main function of the tailstock in a lathe machine? a. Holds cutting tools b. Supports the workpiece from the other end c. Rotates the workpiece d. Controls the speed of the lathe 4. In a lathe machine, what is the purpose of the carriage? a. Holds the workpiece b. Holds the cutting tool and moves it longitudinally c. Holds the chuck d. Holds the tailstock 5. What is the tool used in a lathe machine to remove material from the workpiece? a. Cutter b. Grinder c. Lathe tool bit d. Welder 6. Which of the following is a safety precaution when operating a lathe machine? a. Remove safety guards for better visibility b. Wear loose clothing and jewelry c. Tie back long hair and secure loose clothing d. Ignore the emergency stop button 7. What is the function of the cross slide in a lathe machine? a. Moves the workpiece longitudinally b. Moves the tool perpendicular to the workpiece axis c. Rotates the workpiece d. Holds the chuck 8. What should you do if you notice any unusual sounds or vibrations coming from the lathe machine during operation? a. Ignore it, it will go away b. Increase the speed to see if it stops c. Stop the machine immediately and investigate the cause d. Ask a colleague to check it for you 9. What type of clothing is appropriate for operating a lathe machine? a. Loose-fitting clothes and jewelry b. Tight-fitting clothes and closed-toe shoes c. Shorts and flip-flops d. Lab coat and sandals 10. Why is it important to wear safety goggles or a face shield when operating a lathe machine? a. To protect your eyes from flying debris b. To look professional c. To improve vision in dim light d. To keep hair out of your face 38 LATHE MACHINE OPERATIONS d. To keep hair out of your Definition of Terms Machine Shop - a facility where various types of machine tools and equipment are used to produce, fabricate, or modify metal, plastic, ceramic, composite, or other materials to create precision parts. Workpiece - is the material that machinists and engineers work on to create a specific part or component. This material can be metal, plastic, wood, ceramic, or any other substance that can be shaped, cut, or modified to meet the desired specifications. Caution - A symbol used to indicate a potentially hazardous situation which, if not avoided, could result in death or serious injury. First Aide - An immediate care given to a person who has been injured or suddenly taken illness. Mandatory Sign - Regulatory signs which indicate that an instruction must be carried out. OSHS – Occupational safety and health standard - Mandatory rules standards set and enforced to eliminate or reduce hazard in workplace. Cutting tools - are instruments or devices used in machining processes to remove material from a workpiece Chips - refers to the small pieces of material that are removed from a workpiece during a cutting or machining operation Feed - refers to the rate at which a cutting tool advances or moves through the workpiece during a machining operation Speed - is the speed at which the outer edge of the cutting tool contacts the workpiece. Die - a specialized tool used in manufacturing and metalworking to shape or cut materials using a press Jigs and fixture - are specialized tools used in manufacturing and machining processes to aid in the production of parts with high precision, repeatability, and efficiency. Acronyms PPE- Personal Protective Equipment OSHS- Occupational Safety and Health Standards 39 LATHE MACHINE OPERATIONS Answer Key What did you know about this module? 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. What did you learn in this module? 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 40 MODULE Module 2 MODU LATHE MACHINE OPERATIONSMODULE LE MODULE What is Lathe machine operations module’s all about? This instructional module was designed for those student’s trainees under the course Bachelor of Industrial technology major in mechanical technology. It covers the competencies in lathe machine operations. These competencies are covered and divided in five (5) modules appropriately. Each module also provides you with learning outcomes and attainment of two or more objectives. Addition of definition of key terms and acronym will guide the student to easily understand the module. They can be of great help. Use them fully Module 2 Lathe Machine Setup ▪ Lathe Machine Installation and Leveling ▪ Workpiece Mounting and Centering ▪ Tool Mounting and Tool Post Adjustment ▪ Speed and Feed Selection 42 MODULE LATHE MACHINE OPERATIONS MODULE Learning Objectives: Understand the process of installing and leveling a lathe machine to ensure stability and accuracy in machining operations. Identify the necessary tools and techniques required for proper machine installation and leveling. Learn various methods to securely mount workpieces onto the lathe machine, considering factors such as size, shape, and material. Develop skills in accurately centering workpieces, ensuring alignment and balance for precise machining. Grasp the techniques for mounting different types of cutting tools onto the lathe machine. Gain proficiency in adjusting the tool post to achieve the desired cutting depth, angle, and tool position for efficient machining. Understand the relationship between cutting speeds, feed rates, and the material being machined. Learn how to select appropriate cutting speeds and feed rates based on the type of material and desired machining outcomes. 43 MODULE MODULE LATHE MACHINE OPERATIONS What did you know about this module? TEST YOURSELF Diagnostic test: Choose and encircle the answer in the given question 1. What is the primary purpose of leveling a lathe machine during installation? A) To enhance its appearance B) To prevent vibrations and ensure accuracy in machining operations C) To make it easier to clean D) To improve the machine's color contrast 2. Which tool is commonly used to check the leveling of a lathe machine? A) Vernier Caliper B) Spirit Level C) Micrometer Screw Gauge D) Tachometer 3. What is the purpose of a chuck in lathe machine operations? A) To hold and rotate the workpiece B) To measure the workpiece diameter C) To adjust the machine's speed D) To control the machine's temperature 4. How can you ensure proper centering of a workpiece in a lathe machine? A) By using a dial indicator to check the alignment B) By listening to the sound of the machine C) By checking the machine's color D) By observing the weather conditions 5. What is the purpose of a tool post in a lathe machine? A) To measure the depth of cut B) To hold and secure the cutting tool C) To control the machine's power supply D) To adjust the machine's speed 6. Which adjustment is made on the tool post to achieve different cutting depths? A) Speed adjustment B) Feed adjustment C) Depth of cut adjustment D) Temperature adjustment 45 7. Why is it important to select the appropriate speed for lathe machine operations? A) To save electricity B) To reduce noise pollution C) To ensure safety and achieve desired surface finish D) To minimize the machine's weight 8. What factors should be considered when selecting the feed rate for a lathe machine operation? A) Workpiece material, cutting tool material, and desired surface finish B) Operator's experience level C) Machine's color and appearance D) Ambient temperature in the workshop 9. Which of the following materials is commonly used for lathe machine cutting tools due to its hardness and resistance to wear? A) Aluminum B) Plastic C) High-speed steel (HSS) D) Rubber 10. What safety precaution should be taken while operating a lathe machine? A) Wear loose clothing to stay comfortable during work B) Remove safety guards to have a better view of the machining process C) Always wear appropriate personal protective equipment (PPE) and follow proper operating procedures D) Ignore warning signs and labels on the machine for faster operation 45 MODULE MODULE LATHE MACHINE OPERATIONS Lathe machine Set up Machine Installation and Leveling The lathe machine is a fundamental tool in various industries, used for shaping, cutting, and turning materials. Proper installation and leveling of a lathe machine are essential to ensure precision, safety, and optimal performance. This module provides detailed guidelines and procedures for the installation and leveling of lathe machines, catering to technicians, engineers, and operators involved in this process. Site Preparation Choosing the Right Location: Place the lathe machine on a flat, stable surface. Ensure adequate lighting and ventilation in the workspace. Place the machine near power sources and necessary utilities. Leveling the Machine: Use a spirit level to ensure the machine is perfectly level in all directions. Adjust the machine's feet as needed. Providing Adequate Space: Allow ample space around the machine for safe operation, tool changes, and maintenance activities. Electrical and Power Requirements: Connect the machine to a power source that meets the specified voltage and current requirements. Install appropriate circuit protection devices as per local regulations. Installation Process Assembling the Lathe Machine Components: Follow the manufacturer's instructions for assembling the major components such as the bed, headstock, tailstock, and carriage. Mounting the Lathe Bed: Secure the lathe bed to the foundation using suitable bolts and anchors. Ensure it is stable and immovable. 6 Installing the Chuck and Tailstock: Mount the chuck securely on the spindle according to the chuck manufacturer's guidelines. Align and install the tailstock, ensuring it moves smoothly along the bed. Installing the chuck and tailstock on a lathe machine is a critical step that ensures the proper functioning of the machine. Here is a step-by-step guide on how to install the chuck and tailstock: Installing the Chuck: Inspect the Chuck: Before installation, inspect the chuck for any damage. Ensure it is clean and free from debris. 1) Prepare the Spindle Clean the spindle threads and ensure there is no dirt or debris. Apply a thin layer of lubricant to the spindle threads to facilitate smooth installation. 2) Align the Chuck Align the chuck with the spindle threads. Most chucks have guide pins or markings that help align them correctly. Slide the chuck onto the spindle, and make sure it fits snugly. 3) Tighten the Chuck Use the chuck key provided with the lathe to tighten the chuck onto the spindle. Use the key to turn the chuck clockwise until it is securely tightened. Ensure it is tightened evenly to avoid misalignment. 4) Check Alignment After tightening, check the chuck to ensure it is aligned properly. Use a dial indicator to measure any runout. If there is runout, repeat the installation process, ensuring proper alignment. Installing the Tailstock: 1. Inspect the Tailstock: Inspect the tailstock for any damage or abnormalities. Ensure it is clean and well-lubricated. 7 2. Position the Tailstock: Slide the tailstock onto the lathe bed from the tailstock end. Position it at the desired location on the lathe bed. There are usually markings or measurements on the lathe bed to help position the tailstock accurately. 3. Secure the Tailstock: Most tailstocks have a locking mechanism or clamping lever that secures them in place. Use this mechanism to securely lock the tailstock onto the lathe bed. Make sure it is tight enough to prevent any movement during operation. 4. Check Alignment: Check the alignment of the tailstock with the lathe spindle. It should be parallel to the spindle axis. Use a dial indicator to ensure proper alignment. If there are adjustments needed, consult the lathe's user manual for instructions on how to adjust the tailstock alignment. 5. Test Movement: Check the movement of the tailstock along the lathe bed. It should move smoothly without any excessive resistance. If there is resistance, lubricate the appropriate parts as per the user manual's recommendations. 6. Check Morse Taper Alignment (if applicable): If your lathe machine uses Morse taper for the tailstock, ensure that the tailstock's Morse taper and the lathe spindle's Morse taper are clean and free from burrs. Insert the tailstock center into the spindle and ensure a snug fit. 7. Secure the Workpiece: If you're using the tailstock for supporting a workpiece, adjust the tailstock quill to the appropriate position and lock it in place. Use the tailstock handwheel or locking mechanism to secure the workpiece in position. Always refer to the specific lathe machine's user manual for detailed instructions and specifications related to installing the chuck and tailstock. Following the manufacturer's guidelines ensures the proper and safe installation of these essential components. 8 Adjusting Belts and Pulleys: Adjust the drive belts and pulleys according to the recommended tension and alignment specified in the user manual. Securing Tool Rest and Carriage: Secure the tool rest and carriage on the lathe bed. Adjust and tighten all components to prevent movement during operation. Lubrication and Initial Testing: Lubricate all moving parts according to the lubrication schedule provided in the user manual. Perform initial tests to ensure smooth operation and proper alignment of components. Mounting and centering a workpiece Mounting and centering a workpiece on a lathe machine accurately is crucial for achieving precise machining results. Here's a step-by- step guide on how to mount and center a workpiece on a lathe: 1. Inspect the Workpiece: Check the workpiece for any defects, dirt, or burrs. Ensure it is clean and free from any obstructions. 2. Select the Right Lathe Chuck: Choose an appropriate chuck or faceplate for your workpiece. Different types of chucks (three-jaw, four-jaw, collet chuck, etc.) are suitable for different types of workpieces. 3. Prepare the Lathe Chuck: If you're using a chuck, ensure it is clean and in good condition. Mount it securely onto the lathe spindle following the manufacturer's instructions. 4. Mount the Workpiece in the Chuck: Place the workpiece into the chuck jaws. For a round workpiece, use external jaws. For irregularly shaped pieces, use custom jaws or fixtures. Tighten the chuck jaws securely around the workpiece using the chuck key. Ensure the workpiece is held firmly and doesn’t wobble. 9 5. Centering the Workpiece: A. Using a Dial Indicator (Preferred Method): Centering a workpiece on a lathe using a dial indicator is a precise method that ensures accurate results. Here are the steps to center a workpiece using a dial indicator: Tools and Materials Needed: Dial indicator Magnetic base or other mounting equipment for the dial indicator Chuck or faceplate Workpiece Chuck key/T wrench Steps: 1) Prepare the Lathe: Ensure the lathe machine is turned off. Mount an appropriate chuck or faceplate onto the lathe spindle and secure it tightly using the chuck key. 2) Mount the Dial Indicator: Attach the dial indicator to a magnetic base or other mounting equipment. Position the dial indicator so that its probe is near the workpiece, but without touching it. Adjust the height and angle of the indicator for proper contact. 3) Set the Dial Indicator: Set the dial indicator's plunger against the side of the workpiece. Make sure the plunger can move freely along the diameter of the workpiece. Set the dial indicator's needle to zero by turning the bezel or rotating the dial until the needle aligns with the '0' on the dial. 4) Rotate the Chuck: Rotate the chuck by hand, allowing the workpiece to move past the dial indicator's probe. 10 Observe the Dial Indicator: 5) As the workpiece rotates, observe the dial indicator's needle movement. 6) The needle will move away from zero when the workpiece is not centered. Note the maximum reading on the dial. 7) Adjust the Workpiece Position: Based on the maximum reading observed on the dial indicator, adjust the position of the workpiece in the chuck. If the needle moves, for example, 0.025 inches away from zero, move the workpiece half of this value, or 0.0125 inches, towards the center. 8) Recheck and Fine-Tune: Repeat the process, adjusting the workpiece position slightly each time, until the dial indicator shows minimal or zero movement as the workpiece rotates. 9) Secure the Workpiece: Once the dial indicator shows minimal or zero runout, tighten the chuck jaws securely to hold the workpiece in its centered position. 10)Verify Centering: Double-check the centering accuracy by rotating the workpiece manually and observing any movement of the dial indicator needle. Make any final adjustments if necessary. Adjust the workpiece position in the chuck until the needle shows minimal or zero runout. This indicates the workpiece is centered. B. Using a surface gauge To center a workpiece on a lathe machine using a surface gauge, you can follow these steps: Tools and Materials Needed: Surface gauge Workpiece Chuck or faceplate Chuck key/ T wrench 11 Steps: 1. Prepare the Lathe: Ensure the lathe machine is turned off. Mount the appropriate chuck or faceplate onto the lathe spindle and secure it tightly using the chuck key. 2. Mount the Workpiece: Place the workpiece in the chuck jaws or secure it to the faceplate, depending on the type of workpiece and lathe setup. 3. Position the Surface Gauge: Place the surface gauge on the lathe bed, close to the workpiece but not touching it. Adjust the height of the surface gauge to match the centerline of the lathe spindle. 4. Align the surface Gauge: Align the surface gauge's pointer or notch with the center hole or mark on the end face of the workpiece. 5. Rotate the Chuck: Rotate the chuck by hand, allowing the workpiece to move past the surface gauge's pointer. 6. Observe the surface Gauge: As the workpiece rotates, observe the position of the surface gauge's pointer in relation to the center hole or mark on the workpiece. 7. If the pointer moves away from the center hole or mark, adjust the workpiece position in the chuck accordingly. For example, if the pointer moves to the left, move the workpiece slightly to the right within the chuck jaws. 8. Recheck and Fine-Tune: Repeat the process, adjusting the workpiece position slightly each time, until the c surface gauge's pointer aligns perfectly with the center hole or mark on the workpiece as it rotates. 9. Secure the Workpiece: Once the surface gauge shows that the workpiece is centered, tighten the chuck jaws securely to hold the workpiece in its centered position. 12 10. Verify Centering: Double-check the centering accuracy by rotating the workpiece manually and observing the alignment with the surface gauge. Make any final adjustments if necessary. Begin Machining: Start the lathe machine following the appropriate procedures. Begin the machining operation, ensuring the tool bit does not make contact with the chuck or any other parts of the lathe. Always follow the safety guidelines provided in the lathe machine's user manual, and wear appropriate personal protective equipment (PPE) when operating the lathe. Additionally, consult the specific lathe machine's manual for any unique instructions or considerations related to workpiece mounting and centering for that particular model. Tool Mounting and Tool Post Adjustment Mounting a tool on a lathe involves securing it properly in the toolpost to ensure accurate and safe machining. Here are the general steps for mounting a tool on a lathe: Tools and Materials Needed: Lathe tool Toolpost Wrenches (if required) Lathe machine Steps: 1) Select the Right Tool: Choose the appropriate lathe tool based on the type of operation you are performing (turning, facing, grooving, etc.) and the material you are working with. 13 2) Inspect the Tool: Check the lathe tool for any damage, wear, or dullness. Make sure it is in good condition before mounting. 3) Prepare the Tool post: Open the toolpost and slide the toolholder into the T-slot. Tighten the toolpost clamping bolt to secure the toolpost in place. 4) Mount the Tool in the Toolholder: Insert the lathe tool into the toolholder from the top, ensuring that it fits snugly and is aligned properly. Many lathe tools have specific shapes and grooves that match the toolholder. Ensure the tool fits correctly into these features. 5) Align the Tool: Adjust the tool in the toolholder so that it is at the correct height and angle for the machining operation you are performing. The tool's cutting edge should be on the centerline of the workpiece. 6) Tighten the Toolholder: Use the appropriate wrenches to tighten the toolholder screws or clamps securely. Ensure the tool is held firmly and does not wobble. 7) Set the Tool Height: Adjust the tool's height using the tool post adjustment. Use a height gauge or a dial indicator to set the tool at the correct height relative to the lathe's centerline. 8) Check Clearances: Manually rotate the lathe spindle to check for any interference between the tool and other components, such as the chuck or tailstock. Adjust the tool position if needed to avoid collisions. 9) Secure the Workpiece: If you haven't already, mount and secure your workpiece in the chuck or on the lathe's faceplate, ensuring it is properly centered. 14 10) Perform a Test Run: Start the lathe machine and observe the tool's movement. Make sure there are no unusual vibrations or noises. Check that the tool clears the workpiece without any issues. 11) Make Final Adjustments: Fine-tune the tool position and height if necessary. Use micrometers or dial indicators for precise adjustments. 12) Begin Machining: Once everything is properly set up and adjusted, you can begin the machining operation. Keep a close eye on the cutting process to ensure the tool is working effectively and the workpiece dimensions are as desired. 15 Speed and Feed Selection in Lathe Calculating the appropriate cutting speed and feed rate is crucial for optimizing lathe machining operations. Here are the general formulas and steps for speed and feed computation on a lathe: Cutting Speed (S) Cutting speed is the speed at which the material is removed by the cutting tool from the workpiece. Where: S = Cutting Speed (m/min or ft/min) D = Diameter of the workpiece or the cutting tool (mm or inches) N = Rotational speed of the lathe spindle (revolutions per minute, RPM) Feed Rate (F) Feed rate is the distance the tool advances during one revolution of the workpiece. Where: F = Feed Rate (mm/rev or inches/rev) N = Rotational speed of the lathe spindle (RPM) f = Feed per revolution (mm/rev or inches/rev) z = Number of cutting edges (usually 2 for lathe tools) Steps for Speed and Feed Computation Determine Cutting Speed (S): 1. Measure the diameter of the workpiece or the cutting tool (D). 16 2. Obtain the recommended cutting speed for the material being machined from reference materials or machining guides. 3. Plug the values into the cutting speed formula to calculate the cutting speed (S) in either meter per minute (m/min) or feet per minute (ft/min). 4. Select Feed per Revolution (f): 5. Choose an appropriate feed per revolution value based on the material and tool being used. This value is often provided in machining reference tables. 6. Alternatively, the feed per revolution can be calculated using the desired chip load per tooth and the number of cutting edges on the tool. Chip load per tooth is often specified by tool manufacturers. Determine Feed Rate (F) 1) Determine the rotational speed of the lathe spindle (N) in RPM. 2) Plug the values of N, f, and the number of cutting edges (z) into the feed rate formula to calculate the feed rate (F) in either millimeter per revolution (mm/rev) or inches per revolution (inches/rev). 3) Adjust Speed and Feed as Needed: Consider factors such as tool wear, surface finish requirements, and machine stability. Adjust the cutting speed and feed rate within the recommended ranges to optimize tool life, surface finish, and overall machining efficiency. 17 Name: Date: Written Test 2 Choose and encircle the answer in the given question. 1. "Lathe Machine Installation involves placing the lathe machine on an uneven surface for better stability." a) True b) False 2. "During Lathe Machine Leveling, adjustments are made to ensure the lathe bed is level in both longitudinal and transverse directions." a) True b) False 3. "Workpiece Mounting and Centering is a process that doesn't impact the accuracy of machining operations." a) True b) False 4. "Tool Mounting and Tool Post Adjustment includes securing the cutting tool in the tool holder and making adjustments to achieve the desired angle." a) True b) False 5. "In Workpiece Mounting and Centering, a dial indicator is commonly used to ensure accurate centering of the workpiece." a) True b) False 6. "Speed and Feed Selection involves choosing spindle speeds and feed rates without considering the material being machined." a) True b) False 7. "During Lathe Machine Installation, leveling is not necessary as it doesn't affect machining precision." a) True b) False 8. "In Tool Mounting, the cutting tool should be installed loosely to allow for easy adjustments during machining." 18 a) True b) False 9. "Workpiece Mounting and Centering is only applicable when working with irregularly shaped workpieces." a) True b) False 10. "Speed and Feed Selection is a critical aspect of lathe machine operations, influencing the quality of machining and tool life." 19 Name: Date: Activity no 2. Directions: Perform the following step by step procedure give at least step in Centering of workpiece in a chuck using a dial indicator. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 20 Name: Date: Activity no 3. Directions: Perform the following step by step procedure give at least step in Centering of workpiece in a chuck using a Surface Gauge. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 21 LATHE MACHINE OPERATIONS Republic of the Philippines UNIVERSITY OF RIZAL SYSTEM – Morong Morong Rizal COMPETENCY BASED MODULE IN LATHE MACHINE OPERATIONS RUBRICS IN EVERY ACTIVITIES Total points in Rubrics per Activities Total points Verbal Interpretation 9 - 10 Very - Much Competent 7 - 8 Much Competent 5 - 6 Competent 3 - 4 Slightly Competent 1 - 2 Not Competent RUBRICS IN ACTIVITIES 2&3 SCORE CRITERIA EXPLANATION Work and explanation go above 10 - 9 The students demonstrate and beyond what is expected exceptional mastery, demonstrating advanced Meet the learning objective techniques and accuracy in centering of workpiece. Deep understanding The students display a high level Works is correct and contain 8 - 7 of skill and precision in centering a proper centering techniques workpiece. Meet the learning objectives Error free The students demonstrate basic Work is mostly correct but 6 - 5 competence in centering of contains some error workpiece Almost meet learning objectives Minimal error 22 The students display limited Work contains many errors, but 4 - 3 understanding and application of is somewhat correct centering techniques Partially understanding Several errors 2-1 The students performed minimal Work is mostly incorrect understanding of techniques in Centering of workpiece. Minimal Understanding Frequent Mistakes Need help & Hints 23 What did you learn in this module? TEST YOURSELF 1. What is the primary purpose of leveling a lathe machine during installation? A) To enhance its appearance B) To prevent vibrations and ensure accuracy in machining operations C) To make it easier to clean D) To improve the machine's color contrast 2. Which tool is commonly used to check the leveling of a lathe machine? A) Vernier Caliper B) Spirit Level C) Micrometer Screw Gauge D) Tachometer 3. What is the purpose of a chuck in lathe machine operations? A) To hold and rotate the workpiece B) To measure the workpiece diameter C) To adjust the machine's speed D) To control the machine's temperature 4. How can you ensure proper centering of a workpiece in a lathe machine? A) By using a dial indicator to check the alignment B) By listening to the sound of the machine C) By checking the machine's color D) By observing the weather conditions 5. What is the purpose of a tool post in a lathe machine? A) To measure the depth of cut B) To hold and secure the cutting tool C) To control the machine's power supply D) To adjust the machine's speed 6. Which adjustment is made on the tool post to achieve different cutting depths? A) Speed adjustment B) Feed adjustment C) Depth of cut adjustment D) Temperature adjustment 24 7. Why is it important to select the appropriate speed for lathe machine operations? A) To save electricity B) To reduce noise pollution C) To ensure safety and achieve desired surface finish D) To minimize the machine's weight 8. What factors should be considered when selecting the feed rate for a lathe machine operation? A) Workpiece material, cutting tool material, and desired surface finish B) Operator's experience level C) Machine's color and appearance D) Ambient temperature in the workshop 9. Which of the following materials is commonly used for lathe machine cutting tools due to its hardness and resistance to wear? A) Aluminum B) Plastic C) High-speed steel (HSS) D) Rubber 10. What safety precaution should be taken while operating a lathe machine? A) Wear loose clothing to stay comfortable during work B) Remove safety guards to have a better view of the machining process C) Always wear appropriate personal protective equipment (PPE) and follow proper operating procedures D) Ignore warning signs and labels on the machine for faster operation 25 Definition of Terms 1. Morse Taper- A standardized system for the taper of machine tool spindles and the corresponding tool shanks. It is commonly used in lathes, drill presses, and other machining equipment to provide a secure and accurate fit between the tool and the machine. 2. Burrs- Small, raised edges or particles of material that remain on the surface of a workpiece after machining. Burrs can affect the quality of the finished product and may need to be removed for precision applications. 3. Jaws- In machining, jaws typically refer to the movable or adjustable components of a chuck or vise that hold and secure the workpiece. They can be adjusted to accommodate different sizes and shapes of workpieces. 4. T-Wrench- A type of wrench shaped like the letter "T," often used for tightening or loosening bolts or nuts in machining equipment. It provides a handle for leverage and control. 5. Dial Indicator- A precision measurement instrument with a dial display used to measure small distances, variations, or deviations from a reference point. It often has a plunger or lever that contacts the surface being measured. 6. Runout-The deviation of an object from its intended axis of rotation. In machining, runout is a measure of the eccentricity or wobbling of a rotating component, such as a workpiece or a tool. 7. Surface Gauge- A measuring instrument with a base and an upright post supporting an adjustable spindle or an indicator. It is used for measuring and marking workpieces, as well as for checking the flatness of surfaces. 8. Tool Holder- A device used to secure and support cutting tools in machine tools like lathes and milling machines. It provides a means for accurately positioning and holding the tool during machining operations. 9. Clearance- In machining, clearance refers to the intentional spacing or gap provided between moving parts to avoid interference or collision during operation. It ensures that components can move freely without obstruction. 26 10. Faceplate- A circular, flat metal plate mounted on the spindle of a lathe or other machining equipment. It provides a surface for attaching workpieces directly or using fixtures for various machining operations. 27 LATHE MACHINE OPERATIONS Answer Key: What did you know about this module? TEST YOURSELF 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. What did you learn in this module? TEST YOURSELF 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 28 MODULE 3 1. 4 6 MODULE LATHE MACHINE OPERATIONS What is Lathe machine operations module’s all about? This instructional module was designed for those student’s trainees under the course Bachelor of Industrial technology major in mechanical technology. It covers the competencies in lathe machine operations. These competencies are covered and divided in five (5) modules appropriately. Each module also provides you with learning outcomes and attainment of two or more objectives. Addition of definition of key terms and acronym will guide the student to easily understand the module. They can be of great help. Use them fully Module 3 Basic Lathe Operations 1.Facing Operation 2.Straight Turning Operation 3.Taper turning Operation 1. 4 6 MODULE LATHE MACHINE OPERATIONS MODULE Learning Objectives At the end of the lessons the trainees and the students are expected to: Define basic lathe operations and explain their significance in machining processes; Differentiate between facing, turning, and other lathe operations; Select appropriate cutting tools for each lathe operations based on material, depth of cut, and desired surface finish; Understand the significance of tool positioning and tool angles in achieving desired surface finishes; Apply appropriate feed rates and cutting speeds for different materials and facing depths. 31 MODULE ODULE LATHE MACHINE OPERATIONS What did you know about this module? TEST YOURSELF 1. "Facing Oper "Facing Operation is a turning operation used to create a cylindrical shape on the workpiece." a) True b) False 2. "In Straight Turning Operation, the tool moves parallel to the axis of rotation to reduce the diameter of the workpiece." a) True b) False 3. "Taper Turning Operation is employed to produce a conical shape on the workpiece by gradually changing the diameter." a) True b) False 4. "Facing is a machining process where material is removed from the end of a workpiece to create a flat surface." a) True b) False 5. "Straight Turning is mainly used to create flat surfaces and remove material from the side of a workpiece." a) True b) False 6. "Taper Turning is a type of operation that primarily involves reducing the length of a workpiece." a) True b) False 7. "Facing Operation is commonly used for squaring the ends of cylindrical workpieces." a) True b) False 8. "Straight Turning Operation can be used to create cylindrical shapes and contours on the exterior of a workpiece." a) True b) False 9. "Taper Turning Operation is suitable for creating parallel-sided features on a workpiece." a) True b) False 10. "In Facing, the tool moves radially to the axis of rotation, removing material from the outer diameter of the workpiece." a) True b) False 32 LATHE MACHINE OPERATIONS Basic Lathe Operation The Lathe Cutting Tool (Tool bit) A lathe tool bit is a cutting tool used in metalworking and woodworking lathes to remove material from a workpiece. It is an essential component of a lathe machine and is designed to cut, shape, and finish various materials, such as metal, wood, or plastic, by removing excess material through rotational cutting. Lathe tool bits are typically made from high-speed steel (HSS), carbide, ceramic, or other durable materials. They come in various shapes and sizes, each suited for specific cutting tasks. The tool bit is mounted in the tool holder or tool post of the lathe machine and is secured in place to enable precise and controlled cutting operations. 33 Parts of a Lathe Cutting Tool (Toolbit) When you purchase a new lathe tool bit, it might have an angle on the end, but it is not properly sharpened for turning. Grinding lathe tool bits is a bit of an art. It takes some practice to get good at it. You need to create a cutting edge that is sharp, extends out so that the cutting edge and not the side of the tool contacts the work, but that still has enough support to maintain sufficient strength to cut metal. Before diving in, there are some terms you need to understand. The illustration below shows these terms. First, notice that there are two cutting edges on the tool bit. There is a cutting edge on the end of the tool bit called the front cutting edge. There is also a cutting edge on the side of the tool. © 2002–2012 LittleMachineShop.com 34 Side Cutting Edge The side cutting edge does most of the cutting. As the tool bit moves along the work piece the side cutting edge removes most of the material. Front Cutting Edge The front cutting-edge cuts when the tool is advanced into the work. Nose The nose is a critical part of the cutting edge, because it produces the surface finish of the workpiece. Side Rake The side rake produces the side cutting edge that cuts into the work piece. Side Relief Side relief provides clearance for the side cutting edge. Without side relief, the side of the tool bit would hit the work piece and not allow the cutting edge to penetrate the work piece. Back Rake The back rake produces the front cutting edge that cuts into the work piece. Front Relief Front relieve provides clearance for the front cutting edge. Without front relief, the front of the tool bit would hit the work piece and not allow the cutting edge to penetrate the work piece. 35 How to Sharpen a Tool Bit Use a bench grinder to sharpen your tool bits. Even an inexpensive bench grinder can do a good job grinding lathe tool bits. In some cases, you might want to purchase a higher quality fine grit wheel. Keep a small cup of water near your grinder. Grinding generates heat, which can cause two problems. The tool bit will become too hot to hold. Overheating can also affect the heat treatment of the tool bit, leaving the cutting edge soft. Use a protractor to measure the angles. They are not super-critical, but you should try to stay within one degree of the recommendations. 36 1.Grind the Front Relief The first step in creating a tool bit is to grind the front relief. For most work, a relief angle of 10° works well. While you are grinding the front relief, you are also creating the front cutting-edge angle. Make this angle about 10° also, so that the corner formed by the front cutting edge and the side cutting edge is less than 90°. 2. Grind the Left Side Relief Form the left side relief next. Again, create about a 10° angle. You don’t need to form a side cutting angle. The side cutting edge can be parallel to the side of the tool blank. 3. Grind the Top Rake The top of the tool bit is ground at an angle that combines the back rake and the side rake. The side rake is most important, because the side cutting edge does most of the work. For cutting steel and aluminum, the side rake should be about 12° and the back rake should be about 8°. For cutting brass, the rake angles should be much less, or even 0°. 4. Round the Nose A small nose radius allows you to turn into tight corners. A large nose radius produces better surface finishes. Create a nose radius that is appropriate for the tool bit you are creating. 37 Facing Operation Facing is the process of removing metal from the end of a workpiece to produce a flat surface. Most often, the workpiece is cylindrical, but using a 4-jaw chuck you can face rectangular or odd-shaped work to form cubes and other non-cylindrical shapes. When a lathe cutting tool removes metal it applies considerable tangential (i.e. lateral or sideways) force to the workpiece. To safely perform a facing operation the end of the workpiece must be positioned close to the jaws of the chuck. The workpiece should not extend more than 2-3 times its diameter from the chuck jaws unless a steady rest is used to support the free end. 1. Cutting Speeds If you read many books on machining, you will find a lot of information about the correct cutting speed for the movement of the cutting tool in relation to the workpiece. You must consider the rotational speed of the workpiece and the movement of the tool relative to the workpiece. Basically, the softer the metal the faster the cutting. Don’t worry too much about determining the correct cutting speed: working with the 7x lathes for hobby purposes, you will quickly develop a feel for how fast you should go. Until you get a feel for the proper speeds, start with relatively low speeds and work up to faster speeds. One of the great features of the 7x is that you can adjust the rotational speed without stopping to change belts or gears. Most cutting operations will be done at speeds of a few hundred RPM – with the speed control set below the 12 O’clock position and with the HI/LO gear in the LO range. Higher speeds, and particularly the HI range, are used for operations such as polishing, not cutting. 38 2. Preparing for the Facing Cut 2.1 First, make sure the tumbler gear lever on the back of the headstock is in the neutral (middle) position so that the leadscrew does not rotate. This is very important since you will clamp the half nut on the leadscrew during the facing operation to keep the saddle from being forced back away from the end of the workpiece by the force of the cutting operation. 2.2 Clamp the workpiece tightly in the 3-jaw chuck. To get the work properly centered, close the jaws until they just touch the surface of the work, then rotate the workpiece by hand in the jaws to seat it; then tighten the jaws. It’s good practice to tighten the jaws from all 3 chuck key positions to ensure even gripping by the jaws. 2.3 Choose a cutting tool with a slightly rounded tip. A tool with a sharp pointed tip will cut little grooves across the face of the work and prevent you from getting a nice smooth surface. 39 2.4 Clamp the cutting tool in the tool post and turn the toolpost so that the tip of the cutting tool will meet the end of the workpiece at a slight angle. It is important that the tip of the cutting tool be right at the centerline of the lathe; if it is too high or too low you will be left with a little bump at the center of the face. 2.5 Clamp the toolpost in place and advance the carriage until the tool is about even with the end of the workpiece. Make sure that the compound is not all the way at the end of its travel towards the chuck; about midway in its range of travel is good. 2.6 Set the lathe to its lowest speed and turn it on. Make sure the leadscrew is not turning. Turn the lathe off and press the half-nut lever down to engage the half-nut with the leadscrew. When properly engaged, you should feel the lever click into place in a nearly horizontal position. 2.7 You may have to work the carriage handwheel back and forth a little to get good engagement. Locking the half-nut to the leadscrew will prevent the carriage from moving back away from the workpiece during the facing operation. If this were to happen, the end of workpiece would be a slight cone shape instead of perfectly flat – or the tool might stop cutting entirely. A much better way to lock the carriage in place is to add a carriage lock to your lathe as described on Varmint Al’s site and on my mini lathe mods page. 40 3): Beginning the Facing Cut 41 3.1 Use the compound handwheel to advance the tip of the tool until it just touches the end of the workpiece. Use the cross-feed crank to back off the tool until it is beyond the diameter of the workpiece. Turn the lathe on and adjust the speed to a few hundred RPM – about 10 O’clock setting of the speed control knob. 3.2 Now slowly advance the cross feed handwheel to move the tool towards the workpiece. When the tool touches the workpiece, it should start to remove metal from the end. Continue advancing the tool until it reaches the center of the workpiece and then crank the tool back in the opposite direction (towards you) until it is back past the edge of the workpiece. 3.3 Since we started with the tool just touching the end of the workpiece, you probably removed very little metal on this pass. This is a good idea until you get used to how aggressively you can remove metal without stalling the lathe. Also, since the end of the workpiece can be very uneven, you want to avoid gouging the tool into the end of the workpiece if it hits a high spot. 4) The Roughing Cut: 4.1 Use the compound crank to advance the tool towards the chuck about.010″ (ten one-thousandths of an inch, or one one-hundredth of an inch). If the compound is set at 90 degrees to the cross slide (which is how I usually set mine) then each division you turn the crank will advance the tool.001 (one one-thousandth of an inch) toward the chuck. 42 4.2 If the compound is set at some other angle, say 30 degrees, to the cross slide, then it will advance the tool less than.001 for each division. The exact amount is determined by the trigonometric sine of the angle. Since the sine of 30 degrees is.5 the tool would advance.0005 (five ten-thousandths or 1/2 of one one-thousandth of an inch) for each division in this example. Always wondered why you needed trig? Now you know. 4.3 Here’s a picture of the first pass of a facing operation. I am removing about.010″ of metal in this pass. 5) Cutting on the Return Pass: 5.1 If you crank the tool back towards you after it reaches the center of the workpiece you will notice that it removes a small amount of metal on the return pass. This is because the surface is not perfectly smooth and it is removing metal from the high spots. 5.2 If you need to remove a lot of metal, to reduce the workpiece to a specific length, for example, you can take advantage of this return cut to remove more metal on each pass by advancing the tool a small way into the workpiece on the return pass. Since the tool must plunge into the face of the workpiece, this works best with a fairly sharp pointed tool. 43 MODULE MODULE 6) The Finishing Cut 6.1 Depending on how rough the end of the workpiece was to begin with and how large the diameter is, you may need to make 3 or more passes to get a nice smooth finish across the face. These initial passes are called roughing passes and remove a relatively large amount of metal. 6.2 When you get the face pretty smooth you can make a final finishing cut to remove just.001 to.003″ of metal and get a nice smooth surface. The finishing cut can also be made at higher RPM (say 1500 RPM) to get a smo
