BASIC TEORY OF LATHE OPERATION Sumariyanto: 2007 BASIC TEORY OF LATHE OPERATION

LEARNING ACTIVITIES After 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 mathematically Calculate speed of machine rotation mathematically Set the feed rate according to procedure Lathe operation according to procedure

PARTS OF LATHE Franklin W Olin: 2005

Basic Theory of Lathe Operation Turning principle is to make the circular object with the certain diameter by cutting.

LATHE OPERATION

LATHE OPERATION Turning : 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 threads Knurling : to make a regularly shaped roughness on cylindrical surfaces

WORK HOLDING

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

KINDS AND FUNCTION OF CHUCK Collet chuck is used to hold small workpieces Collet Chuck Thin jobs can be held by means of magnetic chucks. Magnetic Chuck www. engbasics.com www. efunda.com

PREPARE LATHE EQUIPMENTS 1. Lathe 2. A set of chuck 3. A set of tools post 4. Cutting tool 5. Measuring tools 6. Inspection equipment work piece

SETTING LATHE EQUIPMENTS Procedure Opening Chuck

SETTING LATHE EQUIPMENTS Procedure Installing Chuck

INSTALL THE WORK PIECE AT CHUCK Nipping Work Piece at External Diameter Nipping Work Piece at Inside Diameter

USING EQUIPMENT ACCORDING TO PROCEDURE Installing The Work Piece At Chuck

CHECKING THE PLAIN OF WORK PEACE Checking Plain with the Scribel Control Controlling Plain by Dial Indicator

HOLDING WORK PIECE (VIDEO) www.youtube.com

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

INSTALLING AND CHECKING CUTTING TOOLS Too High. Too Low As High As Center

DETERMINE OF FEEDING PARAMETER Cutting Speed (Vc/Cs) Vc : Cutting speed (M/minute) n : Axis rotation speed (RPM) D : Diameter (mm) 1/1000 :1 mm = 1/1000 m

CUTTING SPEED Tables of Cutting Speed For a Few Material Type Materials HSS Carbide Fine Coarse Tool Steel 75 – 100 25 – 45 185 – 230 110 – 140 Low Carbon Steel 70 – 90 25 – 40 170 – 215 90 – 120 Medium Carbon Steel 60 – 85 20 – 40 140 – 185 75 – 110 Cost Iron 40 – 45 25 – 30 60 – 75 Brass 85 - 110 45 – 70 185 – 215 120 – 150 Alumunium 70 – 110 30 – 45 140 – 215 60 – 90

SPEED OF MACHINE ROTATION 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:

FEED RATE Feed Rate Types Coarse 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.

Tables Of Feed Rate To All Kinds Of Materials With The Cutting Tool (HSS). Coarse Turning Smooth Turning inchi mm Inchi Alumunium 0,015-0,030 0,40-0,75 0,005-0,010 0,13-0,25 Bronze. 0,015-0,025 0,40-0,65 0,003-0,010 0,07-0,25 Cast Iron 0,005-0,012 0,13-0,30 Tool Steel. 0,010-0,020 0,25-0,50 Machinery Steel.

BASIC THEORY OF DRILLING Drilling is to make the hole with the drilling tool Drilling

STEPS OF DRILLING USING LATHE Drill the work piece using center drilling Sett the position of tail stock Chuck the working pieces Arrange the spindle speed Install the drill at tail stock Operate the drilling at working pieces Determine of hole depth Finish the drilling process

SINGLE THREAD Basic Theory of Single Thread Single thread is the condition when one circle the work pieces only has one thread path.

KINDS OF THREAD PROFILES Triangle Thread Trapezium Thread Buttress Thread Radius Thread Rectangle Thread

Steps Of Thread Turning Determine lathe type to get the thread of pitch wanted Provide the working pieces according to major diameter thread Install the working pieces correctly Set tool of thread and top carriage correctly Determine pitch by arranging handle at gearbox Kalpakjian Determine the cutting speed, is usually selected by 1/3 from cutting speed is common turning. Calculate the depth of thread cutting Give the long limitation part of working pieces will be threaded Check the result of corect thread pitch with thread picth gauge Do thread cutting correctly. Check the thread which has been made.

LATHE OPERATION (VIDEO) www.youtube.com

Cutting Off Steps of Cutting Off Chuck the working pieces correctly Estimate part that will be cut by closest chuck Cut it manual or automatically Cutting Off

REFERENCES Book work shop Technolgy by Hajra choudry Advances in Manufacturing Technology C.J Thomas DeGarmo: 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 Website www. engbasics.com www. efunda.com Kalpakjian: http://www.nd.edu/~manufact/index3.htm

THANK YOU PRESENTED BY Herianto SMKN 1 PUNGGING