MIAE 311 Manufacturing Processes Lecture 1 LECTURER: MICHAEL REMBACZ, ENG. 1 Manufacturing & Machining Instructor https://www.linkedin.com/in/michael-rembacz-eng-892a1036/ Who am I? Michael Rembacz, Eng. Manufacturing & Machining Instructor 2 https://www.instagram.com/remm.watches/?hl=en Welcome All course content and information will be posted on the course Moodle page. Lectures 13 X 2.5 hours Tutorials 13 X 1.5 hours Labs 4 X 4 hours Textbook: Black, J. T and Kohser, R. A., Materials and Processes in Manufacturing,11th Edition, John Wiley, 2012. Online content and chapters: http://bcs.wiley.com/he-bcs/Books?action=index&itemId=0470924675&bcsId=6493 3 Deliverables Deliverable Laboratory Safety Quiz Timeline: Semester Start: May 4th Semester End: June 17th Due dates for specific deliverable will be indicated in the course outline and the course Moodle page. Laboratory Laboratory Exam Percentage See Lab Manual 20% See Lab Manual Midterm 15% Formal Report 5% Video Presentation 5% Assignments 10% Surprise Quizzes (minimum 5) 5% Final Exam* 40% 4 Deliverables - Laboratory Labs will be deferred to the fall 2020 semester or later. A formal declaration will be sent from the University for this. 5 Introduction What is manufacturing? What are manufacturing processes? Definition: Manufacture: noun man·u·fac·ture ; 1. Something made from raw materials by hand or by machinery 2. The process of making wares by hand or by machinery especially when carried on systematically with division of labor 3. A productive industry using mechanical power and machinery 4. The act or process of producing something 6 Manufacturing Processes How things are manufactured: ◦ ◦ ◦ ◦ What processes entail the manufacturing of various components. Machine selection Tool Selection Optimizing machine, process, tools and time. 7 Manufacturability Can it be made? How? What Process? 8 Manufacturability Now change the Tolerance! What about simple shapes? Dimensions in mm Can we make this? Can we measure this? What process? What Tool? What cost? 9 Metrology: Measurement and Inspection Metrology: noun me·trol·o·gy - The science of measurement Everyday use of measurement and inspection? 1. 2. 3. Application in Engineering 1. 2. 3. "…inspection is to ensure that what is being manufactured will conform to the specifications of the product." DeGarmo pg 223 10 Metrology: Measurement and Inspection Measurement: Fundamental exercise of inspection; Act of measuring or being measured. Why measure? Manufactured parts correspond to the specifications of the product. (QA) Confirm functionality, performance, reliability, process capability, etc. How to measure? ◦ Attributes ( Qualitative, go or not-go, Gaging, decisions) ◦ Variables (quantitative, dimensions, useful for analysis and decision) What to measure? ◦ Size/geometry of tools ◦ Size/geometry of a part from a machine tool Benefits ◦ Determines capability of a process. ◦ Indicates the need of maintenance. ◦ Feedback of manufacturing. 11 Attributes vs Variables Attributes Good or bad, pass or fail, accept or reject Typically with the use of gages, go or no-go Ex. A shaft doesn't fit in either ring gage, it's diameter is too big, therefore no-go Variables Use of measuring tools to determine actual dimensions Ex. Using a micrometer the shaft has a diameter of 1.3742" What determines if the. Value is acceptable or not? TOLERANCE! 12 Attributes vs Variables Attributes Variables •Qualitative •Quantitative •Fast and economical •Slow and expensive •Pass or fail •Exact dimension is needed •Mostly for standard and less severe applications (Automobile) •Useful for highly reliable applications (Aircrafts) •Useful after process development •Needed for development •Large production volume •Small production volume • Not ideal for tight tolerance differences 13 Standards of measurement - Units 14 Accuracy vs precision Low Precision High Accuracy refers to the ability to hit was is aimed and, Precision reefers to the repeatability of the process. High Accuracy Low 15 Allowance and Tolerance Allowance = Clearance or interference between components Tolerance = undesirable but permissible deviation from the desired dimension. Will these parts fit together? Max Shaft Ø = 0.5 + 0.0025 = 0.5025 Min Hole Ø = 0.506 – 0.0025 = 0.5035 0.5035 – 0.5025 > 0 Therefore Clearance 16 Allowance and Tolerance σ𝑛𝑖=1 𝑋𝑖 𝑋ത = 𝑓𝑜𝑟 𝑛 𝑖𝑡𝑒𝑚𝑠 𝑛 𝜇 + 3𝜎 = 𝑈𝑁𝑇𝐿 𝜇 − 3𝜎 = 𝐿𝑁𝑇𝐿 Upper / lower natural tolerance limit 𝜎= σ𝑛𝑖=1 𝑋𝑖 − 𝑋ത 𝑛 2 Statistical analysis requires a sample size to initiate! 17 Allowance and Tolerance 18 Types of Tolerance Limits GD&T 𝑴𝑨𝑿 𝑴𝑰𝑵 Unilateral +𝑻𝑶𝑳 𝑼𝑷𝑷𝑬𝑹 −𝑻𝑶𝑳 𝑳𝑶𝑾𝑬𝑹 Doesn’t have to be + / - 𝑵𝑶𝑴𝑰𝑵𝑨𝑳 Bilateral 𝑵𝑶𝑴𝑰𝑵𝑨𝑳 ± 𝑻𝑶𝑳 Can be + /+ or - /- 19 Types of Tolerance Geometrically - GD&T – MECH 313 • MMC – Parts are made with the largest amount of material possible • LMC - Parts are made with the least amount of material possible • RFS – Regardless of feature size • Datums- Concept/Feature common for design, manufacturing and inspection 20 Types of Allowance – Fits – ANSI ANSI – American National Standards Institute Class 1. Loose fit: large allowance. Accuracy is not essential. Class 2. Free fit: Liberal allowance. For running fits where speeds are above 600 rpm and pressures are 600 psi ( 4.1 MPa) or above Class 3. Medium Fit: Medium allowance. For running fits below 600 rpm and pressure below 600 psi ( 4.1 MPa) and for sliding fits. Class 4. Snug Fit: Zero allowance. No movement under load is intended, and no shaking is wanted. This is the tightest fit that can be assembled by hand Class 5. Wringing fit: zero to negative allowance. Assemblies are selective and not interchangeable. Class 6. Tight fit: slight negative allowance. An interface fit for parts that must not come apart in service and are not to be disassembled or are to be disassembled only seldom. Light pressure is required for assembly. Not to be used to with stand other than very light loads. Class 7. Medium force fit: an interference fit requiring considerable pressure to assemble; ordinarily assembled by heating the external member or cooling the internal member to provide expansion or shrinkage. Used for fastening wheels, crank disks, and the like to shafting. The tightest fit that should be used on cast iron external members. Class8. Heavy force and Shrink fits: considerable negative allowance. Used for permanent shrink on steel members. 21 Types of Tolerance – Fits – ISO (Metric) ISO System of Limits and Fits – International Organization for Standardization MECH 313 3 Types: 1. Clearance Fits 2. Transition Fits 3. Interference Fits NOMINAL HX/gY Ex. 45 H8/g7 Introduction of the IT Grade system – See machinery’s Handbook Shaft or Hole basis system 22 Gage Blocks https://en.wikipedia.org/wiki/Gauge_block 23 Gage Blocks Gage blocks wrung together https://www.youtube.com/watch?v=2lOOl3VxOtE 24 Factors in selecting inspection equipment 1. Gage Capability Rule of 10 – Selected measuring equipment should be 10 times more precise than the tolerance being measured. 14 cm ± 1 cm - Measuring tool must be able to read to the nearest millimeter. 1.500” ± 0.005” – Measuring tool must be able to read to the nearest 0.0005” 2. Linearity – Calibration accuracy over its working range. 3. Repeat Accuracy – How repeatable the device is 4. Stability – How well does the device retain its calibration over time. 5. Magnification - Amplification of the output portion of the device, bigger dials as the dimension gets smaller. 6. Resolution - Sensitivity; smallest input value that can be detected or measured 25 Rulers 26 Combination Squares Take pic ofhow to use combo square Center head Square head Bevel protractor https://www.youtube.com/watch?v=jAGBJQP2dl8 27 Combination Squares 28 Combination Squares Center head Bevel Protractor 29 https://www.youtube.com/watch?v=o8Bd8G21Vv8 Squares 30 Calipers – Vernier, Dial, Digital Precision: Ability to read as small as 0.001” (Some digital claim to read to 0.0005”) https://www.youtube.com/watch?v=F9bThpevHfA https://www.youtube.com/watch?v=rdFwZaRgO8s 31 Calipers – Three possible measurements External Depth Internal 32 Height Gage Vernier Scale https://www.youtube.com/watch?v=Xp9U_0YUF9U Digital Using the scribe to mark a part at a specific height 33 Micrometer Precision: Ability to read as small as 0.0001” 34 Micrometer 35 Inside Micrometer http://www.chicagobrand.com/help/inside_micrometer.html 36 Bore Gage Micrometer http://www.longislandindicator.com/p174.html http://store.gaging.com/Bore_Measurement 37 Depth Micrometer 38 Calipers http://www.lighttoolsupply.com/catalog/Product/MitutoyoSpring-Dividers-and-Calipers-Series-950?productID=345088 39 EDML APP http://users.encs.concordia.ca/~m_rembac/EDML%20APP/ 40 Angular measurement – Bevel Protractor 41 https://www.youtube.com/watch?v=PO-Ab7YfBzY&t=455s Angular measurement – Sine Bar 𝑒𝑥𝑎𝑚𝑝𝑙𝑒: 1" 𝑔𝑎𝑔𝑒 𝑏𝑙𝑜𝑐𝑘 sine bar is 5” long 1 sin 𝛼 = 5 ⇒ 𝛼= sin−1 1 = 11.5369 𝑑𝑒𝑔𝑟𝑒𝑒𝑠 5 42 Gages – Gage Blocks Round gages used for hole diameter, tool calibration or measuring non-parallel faces 43 Gages – Plug GO = 1.1250” NO GO = 1.1260” 44 Gages –Ring 45 Gages - Radius 46 Gages – Thread Pitch Thread gages allow the user to match the pitch (metric) or threads per inch (imperial) and visually determine if acceptable. 47 Gages – Thread Pitch 16 TPI Gage used to show how although the teeth line up with threads, there is a void between. 32 TPI, thread gage is a perfect match. 48 Gages – Deviation Type – Dial Indicators https://www.youtube.com/watch?v=00dl0DxRYvM 5:10 0.05” gage block added as reference. 49 Optical measurement - Microscope 50 Optical measurement - Optical comparator 1. Projection of light over object 2. Measurement using micrometer scales 3. Ability to magnify the feature being measured. 4. Interchangeable lenses allow magnification from 5X, 10X, 31.25X, 50X, 62.5X, 90X, 100X and 125X 51 Optical measurement - Optical comparator 52 Optical measurement - Lasers 53 https://www.youtube.com/watch?v=8I5P-r4ogm4 Optical Flats An optical flat is an opticalgrade piece of glass lapped and polished to be extremely flat on one or both sides, usually within a few tens of nanometres (billionths of a meter). They are used with a monochromatic light to determine the flatness (surface accuracy) of other surfaces, whether optical, metallic, ceramic, or otherwise, by interference. 54 Optical measurement Photographic Pixel recognition Using pixel variation or patterns to identify features. Fast, no contact, accuracy depends on image quality. Modern cameras are very capable!!! 55 Optical measurement 56 CMM https://www.youtube.com/watch?v=844UiRBVxlY 57 CMM - Faro https://youtu.be/vu3lw4-ULKk 58 CMM – How it Measures? 59 CMM – 3D Scanners 60 NDT – Non-Destructive Testing Destructive Non-Destructive Quantitative results Qualitative results Do not require interpretation Skilled interpretation of results Restricted for costly measurements High cost equipment Low material cost Low cost equipment Consistent results More subjective results 61 Surface Roughness 62 Surface Roughness 63 NDT – Non-Destructive Testing 64 NDT – Non-Destructive Testing 65 NDT – Non-Destructive Testing Liquid penetrant Inspection https://www.youtube.com/watch?v=xEK-c1pkTUI http://www.karldeutsch.de/KD_GENERAL_KnowledgeBase_PT_EN_M1.html 66 NDT – Non-Destructive Testing 67 NDT – Non-Destructive Testing 68 NDT – Non-Destructive Testing 69 NDT – Non-Destructive Testing 70 NDT – Non-Destructive Testing 71 NDT – Non-Destructive Testing Leak Testing – Spray with soapy water – are there bubbles? Strain Sensing •Advance Optical – Photo Video at high Resolution •Thermal Testing •Resistivity methods •Xray Computed Topography (CT scan) •Acoustic holography (Ultrasonic Sound) 72 Example 1 73 Example 1 74 Example 2 Draw on board 75 Quality Engineering – Chapter 36 Quality Engineering or Quality Assurance Analysis / Verification of the process after a certain sample size 76 Quality Engineering – Chapter 36 The basic principle of quality control – quality improvement without cost increase 77 Process Capability 78 Process Capability 79 How to define LSL and USL? USL = Upper Specification Limit = Nominal + Tolerance LSL = Lower Specification Limit = Nominal - Tolerance Acceptable min and max taking into account tolerance that will yield the same result, fit or function. Ex: Need a hole in a part to attach it to a base flange as per the figure. We are using a ¼”-20 fastener. What diameter of hole should be have and what are the min and max acceptable values? Draw on board 80 Process Capability Index Ability of the process to yield consistently the aimed output. Ability to meet specifications. 𝐶𝑝 = 𝑃𝑟𝑜𝑐𝑒𝑠𝑠 𝐶𝑎𝑝𝑎𝑏𝑖𝑙𝑖𝑡𝑦 USL = Upper Specification Limit = Nominal + Tolerance LSL = Lower Specification Limit = Nominal - Tolerance σ = Standard Deviation 𝐶 𝑝= 𝑇𝑜𝑙𝑒𝑟𝑎𝑛𝑐𝑒 𝑆𝑝𝑟𝑒𝑎𝑑 𝑈𝑆𝐿 −𝐿𝑆𝐿 = 6𝜎 6𝜎 We want 𝑪𝒑 ≥ 𝟏. 𝟑𝟑 to be considered good. 81 Process Capability Ratio 𝐶𝑝 does not take into account if the process is shifted off center (location of process mean) If off center use 𝐶𝑝𝑘 𝐶𝑝𝑘 = 𝑃𝑟𝑜𝑐𝑒𝑠𝑠 𝐶𝑎𝑝𝑎𝑏𝑖𝑙𝑖𝑡𝑦 Ratio 𝐶𝑝𝑘 = min 𝐶𝑝𝑢 , 𝐶𝑝𝑙 USL = Upper Specification Limit LSL = Lower Specification Limit 𝐶 𝑝𝑢= σ = Standard Deviation 𝐶𝑝𝑢 = 𝑈𝑝𝑝𝑒𝑟 𝑙𝑖𝑚𝑖𝑡 𝐶𝑝𝑙 = 𝐿𝑜𝑤𝑒𝑟 𝑙𝑖𝑚𝑖𝑡 𝐶𝑝𝑙 𝑈𝑆𝐿 − 𝜇 3𝜎 𝜇 − 𝐿𝑆𝐿 = 3𝜎 82 Process Capability - Cp vs Cpk 83 How many samples to inspect? Cost • Factors to Consider • Destructive • Non-Destructive • Attributes • Variables • Type of testing • Time to complete testing This represents inspection cost # of Samples inspected What about cost of dealing with parts out of spec? 84 Process Capability – Correction measures What to do when the process is not capable or out of control: 1. Shift the job to another machine with great process capability. 2. Review the tolerance spread if it can be widened to accept the process being completed. 3. Sorting of the product (accept vs reject) 4. Determine if the precision (repeatability) can be improved by: a) Switching cutting tools, work holding devices or materials. b) Overhaul existing process and/or developing preventative maintenance. c) Finding and eliminating root cause of variability d) Design experiments and Taguchi methods to reduce variability. 85 Six Sigma - Motorola USL - LSL Percent Accuracy Ratio 68.26% 2 95.46% 3 99.73% 7 / 10000 6 99.9999% 3.4 parts per million 86 Taguchi The Taguchi approach uses a truncated experimental design (called an orthogonal array) to determine which process inputs have the greatest effect on the process variability (precision) and which have the least. 87