LATHE OPERATIONBASIC TEORY OF LATHE OPERATIONSumariyanto: 2007

*

LEARNING ACTIVITIESAfter following this study, student must be able to: Prepare lathe equipments Set lathe equipment according to procedure Use lathe equipment according to procedure Understand the lathe operation according to procedure Calculate the cutting speed mathematicallyCalculate speed of machine rotation mathematically Set the feed rate according to procedureLathe operation according to procedure

PARTS OF LATHE

Franklin W Olin: 2005

LATHE OPERATIONBasic Theory of Lathe OperationTurning principle is to make the circular object with the certain diameter by cutting.

LATHE OPERATION

LATHE OPERATIONTurning: to produce straight, conical, curved, or grooved work pieces Facing: to produce a flat surface at the end of the part or for making face grooves.Boring: to enlarge a hole or cylindrical cavity made by a previous process or to produce circular internal grooves.Drilling: to make a hole by fixing a drill in the tailstock Threading: to make external or internal threadsKnurling: to make a regularly shaped roughness on cylindrical surfaces

WORK HOLDING

KINDS AND FUNCTION OF CHUCK- For holding cylindrical stock centered.- For facing/center drillingThis is independent chuck ; generally has four jaws , adjusted individually on the chuck faced by means of adjusting screws Three Jaw ChuckFour Jaw ChuckSumariyanto. 2007

Collet ChuckMagnetic Chuck

Collet chuck is used to hold small workpiecesThin jobs can be held by means of magnetic chucks. KINDS AND FUNCTION OF CHUCKwww. engbasics.com www. efunda.com

PREPARE LATHE EQUIPMENTS 1. Lathe 2. A set of chuck3. A set of tools post4. Cutting tool 5. Measuring tools6. Inspection equipment work piece

*

SETTING LATHE EQUIPMENTSProcedure Opening Chuck

Procedure Installing ChuckSETTING LATHE EQUIPMENTS

INSTALL THE WORK PIECE AT CHUCKNipping Work Piece at External DiameterNipping Work Piece at Inside Diameter

USING EQUIPMENT ACCORDING TO PROCEDUREInstalling The Work Piece At Chuck

CHECKING THE PLAIN OF WORK PEACEControlling Plain by Dial IndicatorChecking Plain with the Scribel Control

HOLDING WORK PIECE (VIDEO)

www.youtube.com

CHECKING THE PLAIN OF DRILL (VIDEO)www.youtube.com

INSTALLING AND CHECKING CUTTING TOOLSToo High.Too LowAs High As Center

DETERMINE OF FEEDING PARAMETERCutting Speed (Vc/Cs)

Vc : Cutting speed (M/minute)n : Axis rotation speed (RPM)D : Diameter (mm)1/1000 :1 mm = 1/1000 m

*

Tables of Cutting Speed For a Few Material TypeCUTTING SPEED

MaterialsHSSCarbideFineCoarseFineCoarseTool Steel75 10025 45185 230110 140Low Carbon Steel70 9025 40170 21590 120Medium Carbon Steel60 8520 40140 18575 110Cost Iron40 4525 30110 14060 75Brass 85 - 11045 70185 215120 150Alumunium 70 11030 45140 21560 90

example:If we will fit the work piece from material of alumunium diameter 40 mm with the HSS. Calculate main axis rotation speed!

Answer:Cutting speed of visible aluminum at table 4.1 for example we take 30 m/ minute. So that its speed is:SPEED OF MACHINE ROTATION

FEED RATECoarse Turning:

Uses the thickness feeding 0,40 mm for the work piece which do not need the high precision. 2. Smooth Turning: Uses the thickness feeding (0,07-0,12) mm for the work piece of needing high precision.Feed Rate Types

Tables Of Feed Rate To All Kinds Of Materials With The Cutting Tool (HSS).

MaterialsCoarse TurningSmooth TurninginchimmInchimmAlumunium0,015-0,0300,40-0,750,005-0,0100,13-0,25Bronze.0,015-0,0250,40-0,650,003-0,0100,07-0,25Cast Iron0,015-0,0250,40-0,650,005-0,0120,13-0,30Tool Steel.0,010-0,0200,25-0,500,003-0,0100,07-0,25Machinery Steel.0,010-0,0200,25-0,500,003-0,0100,07-0,25

BASIC THEORY OF DRILLINGDrilling is to make the hole with the drilling toolDrilling

STEPS OF DRILLING USING LATHE

Drill the work piece using center drilling Sett the position of tail stockChuck the working piecesArrange the spindle speedInstall the drill at tail stockOperate the drilling at working piecesDetermine of hole depthFinish the drilling process

SINGLE THREADBasic Theory of Single ThreadSingle thread is the condition when one circle the work pieces only has one thread path.

KINDS OF THREAD PROFILES

Triangle ThreadTrapezium ThreadButtress ThreadRadius Thread Rectangle Thread

Steps Of Thread TurningDetermine lathe type to get the thread of pitch wantedProvide the working pieces according to major diameter threadInstall the working pieces correctlySet tool of thread and top carriage correctlyDetermine pitch by arranging handle at gearbox Determine the cutting speed, is usually selected by 1/3 from cutting speed is common turning.Calculate the depth of thread cuttingGive the long limitation part of working pieces will be threadedCheck the result of corect thread pitch with thread picth gauge Do thread cutting correctly.Check the thread which has been made.

Kalpakjian

*

LATHE OPERATION (VIDEO)www.youtube.com

Cutting OffSteps of Cutting Off

Chuck the working pieces correctlyEstimate part that will be cut by closest chuck Cut it manual or automaticallyCutting Off

REFERENCESBookwork shop Technolgy by Hajra choudryAdvances in Manufacturing Technology C.J ThomasDeGarmo: E.P. DeGarmo et al, Materials and Processes in Manufacturing, Wiley, 2003.Franklin W Olin:. 2005. Engine Lathe Introduction. College of Engineering.Sumariyanto. 2007. Bubut Dasar. Malang: PPPPGT Malang

Websitewww. engbasics.com www. efunda.comKalpakjian: http://www.nd.edu/~manufact/index3.htm

THANK YOUPRESENTED BY

Herianto

SMKN 1 PUNGGING

*

*

*

*