ENT250: MECHANICAL MANUFACTURING SKILLS ENT 250: MECHANICAL MANUFACTURING SKILLS (KEMAHIRAN PEMBUATAN MEKANIKAL)

ENT250: MECHANICAL MANUFACTURING SKILLS TIME: 8.00 AM – AM, WEDNESDAYS AND THURSDAYS VENUE: ENGINEERING WORKSHOP & TEACHING FACTORY LECTURER: MR. AZIZUL MOHAMAD PLVS: MR. AHMAD FAIZAL, MR. SYAYUTHI & MR. ANUAR TECHNICIANS: MR. ZALIZAM, MR. RIMI RAFEEK & MR. NIZAM

ENT250: MECHANICAL MANUFACTURING SKILLS METROLOGY ( 1 WEEKS) CONVENTIONAL MANUFACTURING – –WELDING ( 2 WEEKS) –CONV. MILLING (2 WEEKS) –CONV. TURNING (2 WEEKS) COMPUTER-AGE MANUFACTURING –CNC TURNING (2 WEEKS) –CNC MILLING (2 WEEKS) –WIRE EDM (2 WEEKS)

ENT250: MECHANICAL MANUFACTURING SKILLS ASSESSMENT –100% COURSEWORK, NO FINAL EXAM LAB REPORT TESTS AND QUIZZES ASSIGNMENTS CASE STUDY MINI PROJECT TEXTBOOK –TECHNOLOGY OF MACHINE TOOLS, 6 TH ED. KRAR, GILL & SMID. MCGRAW-HILL SPECIAL PRICE: RM (RRP RM130.00) –LECTURE NOTES AND LAB MODULES

ENT250: MECHANICAL MANUFACTURING SKILLS MEASUREMENT

ENT250: MECHANICAL MANUFACTURING SKILLS History Egyptians used length called cubit –Equal to length of forearm (middle finger to elbow) James Watt measured tolerances of steam engine with thickness of thin shilling International System of Units (SI) developed in 1960 Two major systems of measurement –Inch system in US and Canada –Metric system for 90% of world

ENT250: MECHANICAL MANUFACTURING SKILLS Metric (Decimal) Systems Jan 16, 1970, Canada adopted SI for implementation throughout Canada by 1980 Dec 8, 1975, US Senate passed Metric Bill Will take long time to convert –All machine tools and measuring devices will have to be redesigned –Long life expectancy of costly machine tools –People resistant to change

ENT250: MECHANICAL MANUFACTURING SKILLS Inch/Metric Dimensioning 1994 ANSI Standards Inch Dimensions –Zero not used before decimal point for values less than 1 inch –Dimension expressed to same number of decimal places as its tolerance Metric Dimensions –Zero used before decimal point if < 1 millimeter –Whole number uses no decimal point nor zero –Decimal fraction of a millimeter – last digit to right of decimal point not followed by zero

ENT250: MECHANICAL MANUFACTURING SKILLS QuantityName Symbol lengthmeterm volumeliter and l massgramg timeminutemin seconds Following is list of some common SI quantities, names, and symbols you are likely to encounter when working in the machine shop. Symbols for Use with SI

ENT250: MECHANICAL MANUFACTURING SKILLS QuantityName Symbol forcenewtonN pressure, stresspascalPa temperaturedegree Celsius°C areasquare meterm 2 velocity (speed)meters per minute m/min meters per second m/s anglesdegrees° minutes' seconds'' electric potentialvoltV electric currentampereA frequencyhertzHz electric capacitancefaradF

ENT250: MECHANICAL MANUFACTURING SKILLS Symbols for Use with SI PrefixMeaningMultiplierSymbol microone-millionth µ millione-thousandth.001 m centione-hundredth.01 c decione-tenth.1 d dekaten10 da hectoone hundred100 h kiloone thousand1 000 k megaone million M These prefixes often used with quantities: length, volume, mass, pressure, stress, area

ENT250: MECHANICAL MANUFACTURING SKILLS BASIC MEASUREMENT

ENT250: MECHANICAL MANUFACTURING SKILLS Inch System Unit of length is the inch –May be divided into fractional or decimal fractions –Fractional system based on binary system Common fractions: 1/2, 1/4, 1/8, 1/16, 1/32, 1/64 –Decimal-fraction system uses base 10 Number written as product of 10 or fraction of 10

ENT250: MECHANICAL MANUFACTURING SKILLS Inch System ValueFraction Decimal one-tenth1⁄10.1 one-hundredth1⁄ one-thousandth1⁄ one ten-thousandth1⁄10, one hundred-thousandth1⁄100, one millionth1⁄1,000,

ENT250: MECHANICAL MANUFACTURING SKILLS Metric System Linear dimensions expressed in multiples and submultiples of meter Millimeter most common Fractions of millimeter expressed in decimals Brief comparison of common inch and metric 1 yd= 36 in. 1 m = in m = 1 km 1 km = mi 1 mi = km

ENT250: MECHANICAL MANUFACTURING SKILLS Inch/Metric Conversion Metric Size mm cm dm m 1 in ft yd

ENT250: MECHANICAL MANUFACTURING SKILLS Fractional Measurement Measured with rulers or calipers Steel rules graduated –Binary-fractional divisions 1, ½, ¼, 1/8, 1/16, 1/32, 1/64 –Decimal fractional divisions decimeters, centimeters, millimeters, half-millimeters –1/64 in. or 0.50 mm. smallest used Precision instruments –Micrometers and verniers used for dimensions of less than 0.50 mm

ENT250: MECHANICAL MANUFACTURING SKILLS Steel Rules Metric steel rules graduated in millimeters and half-millimeters –Linear measurement without great accuracy –Lengths from 15 c. to 1 m. Factional steel rules graduated in common binary fractions (1/8 – 1/64 in.) –Several varieties (spring-tempered, flexible, narrow, and hook) –Lengths range from 1 to 72 in.

ENT250: MECHANICAL MANUFACTURING SKILLS Measuring Lengths Fairly accurate measure with steel rules –Butt end of rule against shoulder or step Steel rules become worn with constant use –Can make measurements taken from end inaccurate –Compensate by measuring from 1-in or 1-cm mark and subtracting 1 from measurement Keep edge of rule parallel to edge of work Rule used as straightedge to test flatness of workpieces –Edges ground flat: place, hold to light and view

ENT250: MECHANICAL MANUFACTURING SKILLS Outside Calipers Not precision tools Used to approximately measure outside surface of either round or flat work Do not use when accuracy <.015 in.needed Several styles –spring joint –firm joint Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

ENT250: MECHANICAL MANUFACTURING SKILLS Inside Calipers Used to measure diameter of holes or width of keyways and slots Several styles –Spring joint –Firm Joint Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

ENT250: MECHANICAL MANUFACTURING SKILLS MICROMETERS

ENT250: MECHANICAL MANUFACTURING SKILLS Precision Measuring Tools Five categories of tools based on the dimension being measured –Outside –Inside –Depth –Thread –Height

ENT250: MECHANICAL MANUFACTURING SKILLS Micrometer Caliper Standard inch micrometer accurate to.001 in. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

ENT250: MECHANICAL MANUFACTURING SKILLS Principle of the Inch Micrometer Two important thread terms –Pitch Distance from point on one thread to corresponding point on next thread Inch threads pitch expressed as 1/N(Number of threads) Metric threads expressed in millimeters –Lead Distance screw thread advances axially in one complete revolution

ENT250: MECHANICAL MANUFACTURING SKILLS Principle of the Inch Micrometer Zero line on thimble lined up with index line on sleeve (barrel) –Measuring faces just touch Pitch is 1/40 (.025) in. since 40 threads –One complete revolution of spindle, one line appears –Every fourth line longer (represents.100 in.) Thimble has 25 equal divisions –Represents.001 in.

ENT250: MECHANICAL MANUFACTURING SKILLS To Read Standard Inch Micrometer Note last number showing on sleeve and multiply by.100 Note number of small lines visible to right and multiply by.025 Note number of divisions on thimble from zero to line that coincides with index line on sleeve and multiply by.001 Add three products to get total reading Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

ENT250: MECHANICAL MANUFACTURING SKILLS Sample Reading Note last number showing on sleeve and multiply by.100 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 2 x

ENT250: MECHANICAL MANUFACTURING SKILLS Sample Reading Note number of small lines visible to right and multiply by.025 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 3 3 x

ENT250: MECHANICAL MANUFACTURING SKILLS Sample Reading Note number of divisions on thimble from zero to line that coincides with index line on sleeve and multiply by.001 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 13 x

ENT250: MECHANICAL MANUFACTURING SKILLS Sample Reading Add three products to get total reading Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display in.

ENT250: MECHANICAL MANUFACTURING SKILLS Vernier Micrometer Added to sleeve Each division on vernier scale has a value of.0001 in. Scale consists of 10 divisions that run parallel to index line. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Friction thimble

ENT250: MECHANICAL MANUFACTURING SKILLS To Read Vernier Micrometer Read as would a standard micrometer Note line on vernier scale that coincides with one on thimble –Indicates number of ten-thousandths –Multiple the line number times.0001 Add to total of the other readings

ENT250: MECHANICAL MANUFACTURING SKILLS Metric Micrometer Similar to inch micrometer with two exceptions –Pitch of spindle screw (0.5 mm) –Graduations on sleeve and thimble Above index line on sleeve, graduations in millimeters (from 0 to 25) with every fifth line numbered Below index line, each millimeter subdivided into two equal parts of 0.5 mm Thimble circumference in 50 equal divisions (0.01mm)

ENT250: MECHANICAL MANUFACTURING SKILLS To Read Metric Micrometer Note number of last main division showing above line to left of thimble Multiply that number by 1 mm If there is half-millimeter line showing below index line, between whole millimeter and thimble, add 0.5 mm Multiply number of line on thimble that coincides with index line times 0.01 Add these products

ENT250: MECHANICAL MANUFACTURING SKILLS Metric Vernier Micrometer In addition to graduations on standard micrometer, has five vernier divisions on barrel (each =.002 mm) Major division below index line –Each = 1 mm Minor division above index line –Each =.5 mm Fifty divisions around thimble –Each =0.1 mm)

ENT250: MECHANICAL MANUFACTURING SKILLS Metric Vernier Reading THIMBLE SLEEVE MAJOR DIVISION Graduation = 1mm MINOR DIVISION Graduation = 0.5 mm VERNIER DIVISIONS Each division = mm Graduation = 0.01 mm =10.164

ENT250: MECHANICAL MANUFACTURING SKILLS Combination Inch-Metric Micrometer Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Will give readings in both inch and metric Digital reading for one system, standard barrel and thimble reading for other Another type has dual scales on sleeve and thimble

ENT250: MECHANICAL MANUFACTURING SKILLS Testing Accuracy of Micrometers Test periodically to ensure accuracy Clean measuring faces before testing Turn thimble using friction thimble or ratchet stop until measuring faces contact each other –Zero line on thimble coincides with center index line on sleeve = accuracy Can also check by measuring gage block or other known standard

ENT250: MECHANICAL MANUFACTURING SKILLS Adjusting Accuracy of a Micrometer Clean measuring faces; inspect for damage Close measuring faces carefully by turning ratchet stop or friction thimble Insert C-spanner into hole or slot in sleeve Carefully turn sleeve until index line on sleeve coincides with zero line on thimble Recheck accuracy

ENT250: MECHANICAL MANUFACTURING SKILLS Special-Purpose Micrometers Direct-reading micrometer –Additional digital readout built into frame Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Large-frame micrometer –Made for measuring large outside diameters up to 60 in. –Interchangeable anvils give range of 6 in.

ENT250: MECHANICAL MANUFACTURING SKILLS Other Micrometers Indicating micrometer –Uses indicating dial and movable anvil –Accurate to ten-thousandths of an inch –Can be used as a comparator with gage blocks Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Mul-T-Anvil micrometer Used for measuring tubing and distances from a slot to an edge Round and flat anvils

ENT250: MECHANICAL MANUFACTURING SKILLS Digi-Matic Micrometer Used as hand gage for inspecting small parts Accurate up to 50 millionths of an inch and displays both inch or metric sizes Statistical process control when added provides stand-alone inspection system –Interface with PC Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

ENT250: MECHANICAL MANUFACTURING SKILLS Screw Thread Micrometers Measures pitch diameter of threads Pointed spindle and double-V swivel anvil –Shaped to contact pitch diameter of thread Equal to outside diameter less depth of one thread Limited to certain range –Four ranges for one-inch 8-13 TPI TPI TPI TPI Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

ENT250: MECHANICAL MANUFACTURING SKILLS Screw Thread Micrometers Ranges stamped on micrometer frame Metric available also in ranges –0-25 mm –25-50 mm –50-75 mm – mm Helix angle of thread can give slightly distorted reading –First set thread micrometer to thread plug gage

ENT250: MECHANICAL MANUFACTURING SKILLS VERNIER CALIPERS

ENT250: MECHANICAL MANUFACTURING SKILLS Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Used to lock readings into place Parts of the Vernier Caliper Manufactured with both 25- and 50-division vernier scales Bar of 25-division vernier scale graduated same as micrometer

ENT250: MECHANICAL MANUFACTURING SKILLS Reading the Measurement Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. A 50-division inch vernier caliper reading of in. 1 x 1.000= x 0.100= x 0.050= x 0.001= in.

ENT250: MECHANICAL MANUFACTURING SKILLS Metric Vernier Caliper Many have both metric and inch graduations Parts same as inch vernier Main scale graduated in millimeters –Every main division numbered, equal to 10 mm –Fifty graduations on sliding scale with every fifth one numbered 50 graduations occupy same space as 49 graduations on main scale (49 mm) 1 vernier division = 0.98 mm so difference between 1 main scale division and 1 vernier division =.02 mm

ENT250: MECHANICAL MANUFACTURING SKILLS Reading a Metric Vernier Caliper Last numbered division on bar to left of vernier scale represents number of millimeters multiplied by 10 Note how many full graduations showing between this numbered division and zero –Multiply number by 1 mm Find line on vernier scale that coincides with line on bar and multiply by 0.02 mm Add for total reading

ENT250: MECHANICAL MANUFACTURING SKILLS Direct-Reading Dial Caliper Dial indicator, hand attached to pinion, mounted on sliding jaw Metric: 1 revolution of hand = 2 mm of travel Inch: 1 revolution =.100 or.200 in. of travel –Depends on manufacturer Most have narrow sliding blade attached to sliding jaw (and dial) used depth gage

ENT250: MECHANICAL MANUFACTURING SKILLS Digital Electronic Caliper Can provide readings to resolution of.0005 in. or 0.01 mm at touch of button No rack, pinion or glass scale Can connect to Statistical Process Control (SPC) equipment for inspection purposes Measurements –Inside diameter –Outside diameter –Step –Depth Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

ENT250: MECHANICAL MANUFACTURING SKILLS FOR THE NEXT CLASS… PLEASE GO TO THE RESPECTIVE VENUE BASED ON YOUR GROUP:YOUR GROUP –GROUP A => ENGINEERING WORKSHOP, PIC: MR ANUAR & MR SYAYUTHI –GROUP B => TEACHING FACTORY, PIC: MR AHMAD FAIZAL & MR. AZIZUL ASSIGNMENT 1: PLEASE SEE PORTAL, DUE 26 TH JULY 2006, 5.00 PM & MY OFFICE IN JEJAWI