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BALAJI INSTITUTE OF TECHNOLOGY &

SCIENCE

LABORATORY MANUAL

Of

MACHINE TOOLS

III B. Tech ME

DEPARTMENT OF

MECHANICAL ENGINEERING

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CONTENTS

LIST OF EXPERIMENTS AS PER THE UNIVERSITY ........................................................ 3

LIST OF EXPERIMENTS TO BE CONDUCTED .................................................................. 3

GENERAL INSTRUCTIONS ................................................................................................... 4

GENERAL INFORMATION .................................................................................................... 5

MACHINING PROCESSES ..................................................................................................... 6

1. INTRODUCTION OF GENERAL PURPOSE MACHINES ............................................ 8

2. STEP TURNING OPERATION ........................................................................................ 9

3. TAPER TURNING OPERATION ................................................................................... 11

4. THREAD CUTTING OPERATIONS .............................................................................. 14

5. DRILLING AND TAPPING ON RADIAL DRILLING MACHINE ............................. 16

6. KEY WAY CUTTING ON MILLING ............................................................................ 18

7. SURFACE GRINDING ................................................................................................... 20

8. MAKING A STEPPED BLOCK ON SHAPER .............................................................. 22

LINE DIAGRAM OF ENGINE LATHE MACHINE ............................................................. 24

LINE DIAGRAM OF SHAPING MACHINE ........................................................................ 24

LINE DIAGRAM OF HORIZONTAL MILLING MACHINE .............................................. 25

LINE DIAGRAM OF SURFACE GRINDING MACHINE ................................................... 25

LINE DIAGRAM OF RADIAL DRILLING MACHINE....................................................... 26

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LIST OF EXPERIMENTS AS PER THE UNIVERSITY.

1. Introduction of general purpose machines -Lathe, Drilling machine, Milling machine, Shaper, Planing machine, slotting machine, Cylindrical Grinder, surface grinder and tool and cutter grinder.

2. Step turning and taper turning on lathe machine. 3. Thread cutting and knurling on -lathe machine. 4. Drilling and Tapping. 5. Shaping and Planing. 6. Slotting. 7. Milling. 8. Cylindrical Surface Grinding. 9. Grinding of Tool angles.

LIST OF EXPERIMENTS TO BE CONDUCTED

1. Introduction of general purpose machines -Lathe, Drilling machine, Milling machine, Shaper, Planing machine, slotting machine, Cylindrical Grinder, surface grinder and tool and cutter grinder.

2. Step turning and taper turning on lathe machine. 3. Thread cutting on -lathe machine. 4. Drilling and Tapping. 5. Shaping. 6. Milling. 7. Surface Grinding.

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GENERAL INSTRUCTIONS

1. Every student should obtain a set of instruction sheets entitled manufacturing processes Laboratory.

2. For reasons of safety, every student must come to the laboratory in shoes. it is unsafe for the students to come to the laboratory wearing garments with parts that that hang about loosely. Students should preferably Use half-sleeve shirts. The Students should also ensure that floor around the machine is clear and dry (not oily) to avoid slipping.

3. Students not wearing an apron will not be permitted to the work in the laboratory. 4. Instruments and tools will be issued from the tool room. Every student must produce

his identity card for the purpose. Tools, etc. must be returned to the tool room on the same day.

5. The student should take the permission of the Lab Staff / Tutor before handling any machine.

6. The student should not lean on the machine when it is working. 7. Power to the machines will be put off 10 minutes before the end of laboratory session

to allow the students to return the tools. 8. Students are required to clear off the chips from the machine and lubricate the guides

etc. at the end of the session. 9. Laboratory reports should be submitted on the day of the experiment.

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GENERAL INFORMATION

This laboratory is aimed at providing an introduction to the Know-how of common processes used in industries for manufacturing parts by removal of material in a controlled manner. Auxiliary methods for machining to desired accuracy and quality will also be covered. The emphasis throughout the laboratory course will be on understanding the basic features of the processes rather than details of constructions of machine, or common practices in manufacturing or acquiring skill in the operation of machines. Evidently, acquaintance with the machine is desirable and the laboratory sessions will provide adequate opportunity for this.

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MACHINING PROCESSES

Machining is one of the processes of manufacturing in which the specified shape to the work piece is imparted by removing surplus material. Conventionally this surplus material from the work piece is removed in the form of chips by interacting the work piece with an appropriate tool. This mechanical generation of chips can be carried out by single point or multi point tools or by abrasive operations these are summarized below:

Machining Processes

Single point tool operations Multi-point tool operations Abrasive operations

1. Turning 1. Milling 1. Grinding 2. Boring 2. Drilling 2. Lapping 3. Planing 3. Tapping 3. Honing 4. Shaping 4. Reaming 4.Super-finishing

5. Hobbing 6. Broaching 7. Sawing

The process of chip formation in metal cutting is affected by relative motion between the tool and the work piece achieved with the aid of a device called machine tool. This relative motion can be obtained by a combination of rotary and translatory movements of either the tool or the work piece or both. The kind of surface that is produced by the operation depends on the shape of the tool and the path it traverses through the materials. When the work piece is rotated about an axis and the tool is traversed in a definite path relative to the axis, a surface of revolution is generated. When the tool path is parallel to the axis, the surface generated is a cylinder as in straight turning or boring operations. Similarly, planes may be generated by a series of straight cuts without rotating the work piece as in shaping and planning operations (Fig.3). In shaping the tool is reciprocating and the work piece is moved crosswise at the end of each stroke. Planning is done by reciprocating the work piece and crosswise movement is provided to the tool.

Surface may be machined by the tools having a number of cutting edges that can cut successively through the work piece materials. In plane milling, the cutter revolves and moves over the work piece as shown Fig. 4. The axis of the cutter is parallel to the surface generated. Similarly in drilling, the drill may turn and be fed into the work piece of the work piece may revolve while the drill is fed into it (Fig.5).

The machine tools, in general, provide two kinds of relative motions. The primary motion is responsible for the cutting action and absorbs most of the power required to perform the machining action. The secondary motion of the feed motion may proceed in steps or continuously and absorbs only a fraction of the total power required for machining. When the secondary motion is added to the primary motion, machine surfaces of desired geometric characteristics are produced.

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1. INTRODUCTION OF GENERAL PURPOSE MACHINES

Aim:

To study different types of machine tools (lathe, shaper, planer, milling, drilling and slotter)

Procedure:

1. Neat diagram of following machine tools to be drawn. 2. Brief description of the machine tools to be given. 3. Important parts to be labelled and marked. 4. Accessories should be indicated. 5. Different function of the machine tool can perform to be described.

Machine tools:

1. Different types of lathes. 2. Different types of drilling machine. 3. Different types of milling machines. 4. Shaper. 5. Planer. 6. Slotter. 7. Grinding machines.

Precautions:

1. How various operations can be performed on a particular machine tool and the precautions required for that to be remembered.

2. Upkeep and usual maintenance of the machine tools must be well understood.

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2. STEP TURNING OPERATION

Aim:

To perform a step turning operation on the given cylindrical work piece

Apparatus:

1. Lathe with standard accessories. 2. Work piece

Principle:

Turning is a lathe operation in which an external cylindrical surface is produced by generating. The cutting Tool is first adjusted for the desired depth of cut, using the cross slide. Then as the work piece rotates, the cutting tool is advanced relatively slowly I a direction parallel to the rotational axis of the spindle. The motion is known as the feed. These combined motions cause the work piece by adjusting the feed so that the helical path of the tool tip overlaps and generates a cylindrical surface on the work piece. A spindle rpm which gives a desired cutting speed at the circumference of the cylindrical surfaces should be reflected.

Tools:

Steel rule, outside calipers, tool holder with key, chuck key, HSS cutting Tool bit.

Material: Mild Steel round rod of diameter 20 mm

Procedure:

Initially the given work piece is fitted the chuck using a chuck key. The high speed tool bit is positioned in the tool cutting is kept at an angle to the axis of the given work piece. During this process positioned in the tool holder, the speed of the lathe is high. After this operation, the diameter of the work piece is to be reduced according to the given dimensions by turning process. While doing the work piece one end of the work piece is reduced to the required diameter and after this, chamfering. Process if performed by burning the tool but at 450 inclination and by bringing the tool in contact with the edge of the job, this process removes all sharp edges of the component.

Precautions:

1. The chuck key must be removed immediately after the use.

2. The power supply switched off before measuring diameter.

3. Before performing facing they must be in same line.

Result:

The required steps are made on the work piece for the given dimensions.

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Step turning

Note: All dimensions are in mm

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3. TAPER TURNING OPERATION

Aim:

Test Procedure to perform Taper turning operation by Compound Rest Swiveling method on the given cylindrical work piece.

Apparatus:

1. Lathe with standard accessories. 2. Work piece

Principle:

Cutting Tapers on a lathe is common application. A number of methods are available for cutting tapers on a lathe.

They are:

1. Compound rest Swivelling Method.

2. Using form tools.

3. Tail stock offset method.

4. Taper attachment method.

These methods are used for turning steep and short tapers. There is a circular base graduated in degrees which can be swivelled at any angle from the centre line of the lathe centres. The amount of taper in a work piece is usually specified by the ratio of the difference in diameters of the taper to its length. This is termed as conicity and is designated by the letter K.

Conicity K = (D-d)/(2l)

Tools:

Chuck key, high speed Steel (HSS) cutting tool bit, outside callipers, Tool Holder with key, spanner etc.

Material:

Mild Steel round rod of diameter 20 mm

Procedure:

The work piece is fixed in the tool post tightly and the center of head stock and tail stock is coincided with the centers of head stock and tail stock. Facing and plain turning operations are performed to get the required diameter on the work piece. The compound rest is set on the required half taper angle and is locked by the cutting rod is adjusted to a fixed position for the best possible to the open hand wheel and cross feed. Then the carriage is locked and first

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cut is made at the end of the cut, the tool is again cross fed is given for the next cut. Cuts are repeated piece is then removed from the chuck and dimensions obtained

Precautions:

1. The work piece should be fixed tight in the jaw.

2. The power supply switched off before measuring diameters.

Result:

The required steps are made on the work piece for the given dimensions.

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Taper turning

Note: All dimensions are in mm

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4. THREAD CUTTING OPERATIONS

Aim:

Test Procedure to perform Thread cutting operation on the given cylindrical work piece.

Apparatus:

1. Lathe with standard accessories

2. Work piece

Material:

Mild Steel round rod of diameter 20 mm

Procedure:

The given work piece is fixed tightly in the 3 jaw chuck. Facing and turning operations are done to make the diameter equal to the major diameter of the screw thread. According to the given Pitch, the necessary gearing ratio is calculated. The feed selection lever that unlocks the half-nut lever for use, is set on the carriage apron for cutting metric threads, the included angle of the cutting edge should be ground exactly 600, the thread cutting tool is fixed in the tool post so that the tip of the tool coincides with the axis of the work piece the lathe spindle speed is reduced by on half, on forth of the speed required for turning by back gear mechanism or quick change levers. The half nut lever engaged at the end of the cut, the spirit nut lever disengages the carriage and the tool is withdrawn to its position sufficient depth is given for each cut using the cross slide the process is repeated till the required dimensions are obtained.

Precautions:

1. For cutting right threads the change gears should be so arranged that the direction of the lead screw is in same direction as that of the rotation of spindle.

2. The work piece should be fixed tight in the jaw.

3. The power supply switched off before measuring diameters.

Result:

Thread with required pitch is produced on the given work piece.

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Thread cutting.

Note: All dimensions are in mm

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5. DRILLING AND TAPPING ON RADIAL DRILLING MACHINE

Aim:

To perform drilling, reaming and tapping operations on the given M.S Flat workpiece.

Apparatus:

1. Drilling Machine with standard accessories

2. Work piece

Material:

Mild Steel round rod of diameter 20 mm.

Procedure:

1. The given work piece is first fitted to get required length, breadth and thickness wet chalk is applied on four sides and with the scriber lines are drawn to get centre hole at required location.

2. The centres are punched with a Punch and hammer.

3. The work piece is fixed firmly in the vice of the Drilling Machine

4. 3/8” drill bit is fixed firmly in the chuck and drilling is performed giving uniform depths.

5. The drill bit is removed from the drill chuck and is replaced by a reamer.

6. The reaming operation is performed on the hole which has been previously drilled.

7. The work is removed from the vice for performing tapping operation.

8. The job is fixed firmly in a bench vice.

9. Tap is fixed in the tap handle and pressure applied on the taps to obtain internal thread.

Precautions:

While performing reaming and tapping operations lubricant should be used to minimize friction.

Result:

Drilling and Tapping operations are performed on the given work piece as per given dimensions.

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Drilling

Note: All dimensions are in mm

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6. KEY WAY CUTTING ON MILLING

AIM: To perform the key way cutting on Milling machine.

TOOLS AND EQUIPMENT: Milling machine, side end or face cutter, Key slot milling cutter, vernier calliper, odd leg calliper. SEQUENCE OF OPERATIONS:

1. Hold the work piece in a vice or holding device, set the side end or face cutter, plain

milling cutter to the Arbor support.

2. Raise the table to the required position.

3. Adjust the cutting speed and feed.

4. Start the machine after selecting the proper speed and feed.

5. Perform the plain milling operation and all sides of work piece.

6. Mark the dimensions on the work piece.

7. Perform the key way cutting operation.

PRECAUTIONS:

1. Do not wear loose clothes.

2. While measuring the work piece dimensions, stop the milling machine.

3. Ensure the optimum feed and depth of cut and must be maintained during the machine

operation.

4. Do not start a machine of which operation is not known. Damage to the machine as

well as accident may occur.

Before starting the work check whether all levers are in proper position.

Result:

The required steps are made on the work piece for the given dimensions.

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Key way on milling

Note: All dimensions are in mm

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7. SURFACE GRINDING

AIM: To perform the fine surface Grinding operation on a given work piece.

TOOLS AND EQUIPMENT: Surface grinding machine, steel rule.

MATERIAL REQUIRED:

M.S Flat ( 60x45x5)mm3 SEQUENCE OF OPERATION:

1. Mark the require dimensions on the work piece.

2. Hold the work piece in the magnetic chuck.

3. Adjust the grinding wheel on to the work piece.

4. Start the machine and perform grinding operation.

5. Reduce the required thickness on the work piece by grinding operation. Perform fine

finishing operation on the work piece.

PRECAUTIONS:

1. Do not wear loose clothes.

2. While measuring the work piece dimensions, stop the grinding machine.

3. Ensure the optimum feed and depth of cut and must be maintained during the

operation accident may occur.

4. Do not start a machine of which operation is not known. Damage to the machine as

well as accident may occur.

5. Before starting the work chuck whether all levers are in proper position.

RESULT:

Work piece has been machined according to given measurement.

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Surface grinding

Note: All dimensions are in mm

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8. MAKING A STEPPED BLOCK ON SHAPER

AIM: To perform the Step cutting operation on shaper

TOOLS AND EQUIPEMEANT: Shaper machine tool, Planing tool, Key way cutting tool, Vernier calliper. PROCEDURE:

1. Hold the work piece in a vice or holding device.

2. Set the planing tool in the tool head with minimum overhang. Raise the table up to

required position.

3. Adjust the length and position of the stroke.

4. Adjust the cutting speed and feed.

5. Perform planning operation on the work piece.

6. Mark the dimensions on the work piece.

PRECAUTIONS:

1. Do not wear loose clothes 2. While measuring the work piece dimensions, stop the machine 3. Ensure the optimum speed, feed and depth of cut during the machine operation. 4. Do not start the machine, of which operation is not known damage to the machine as

well as accident may occur. 5. Before starting the work, check whether all levers are in proper position.

RESULT Stepped block has been produces on Shaping machine

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Stepped block

Note: All dimensions are in mm

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LINE DIAGRAM OF ENGINE LATHE MACHINE

LINE DIAGRAM OF SHAPING MACHINE

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LINE DIAGRAM OF HORIZONTAL MILLING MACHINE

LINE DIAGRAM OF SURFACE GRINDING MACHINE

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LINE DIAGRAM OF RADIAL DRILLING MACHINE