Lab Manual

DHANALAKSHMI SRINIVASAN INSTITUTE OF TECHNOLOGYSAMAYAPURAM - TRICHY

S.No Experiment NameDate of

ExperimentMarks Signature

Metal Cutting experiment1. Shear angle calculation2. Cutting force calculation3. Tool wear calculation

Material Removal using Slotter, Milling and Planer machines

4. Internal keyway cutting in Slotter machine

5. Round to square in planer

6.Gear milling in milling machine

7.Keyway cutting in milling machine

Grinding8. Surface grinding9. Cylindrical grinding

Capstan and turret lathe10. Study

11.Drilling, Countersinking and Reaming in Capstan and Turret lathe

Gear machining

12.Gear manufacturing using gear hobbing.

ME2258 MANUFACTURING TECHNOLOGY LAB 2 MANUAL


General Shop Safety

All tools are dangerous if used improperly or carelessly. Working safely is the first thing the user or operator should learn because the safe way is the correct way. A person learning to operate machine tools must first learn the safety regulations and precautions for each tool or machine. Most accidents are caused by not following prescribed procedures. Develop safe work habits rather than suffer the consequences of an accident.

Most of the safety practices mentioned in this section are general in nature. Safety precautions for specific tools and machines are described in detail in the chapters along with the description of the equipment. Study these carefully and be on the alert to apply them.

EYE PROTECTION

Using eye protection in the machine shop is the most important safety rule of all. Metal chips and shavings can flyat great speeds and distances and cause serious eye injury.

Safety glasses must be worn when working with hand cutting tools, since most hand cutting tools are made of hardened steel and can break or shatter when used improperly.

There are many different types of safety glasses available in the supply system; however, the ones that offer the best protection are the safety glasses with side shields. Safety goggles should be worn over prescription glasses. For specific information about eye protection, contact the Occupational Health Clinic or refer to TB MED 586.

HAZARDOUS NOISE PROTECTION

Noise hazards are very common in the machine shop. High intensity noise can cause permanent loss of hearing. Although noise hazards cannot always be eliminated, hearing loss is avoidable with ear muffs, ear plugs, or both. These are available through the local supply system or from the Occupational Health Clinic. Ear plugs must be properly fitted by qualified personnel. For specific information on hearing protection, refer to TB MED 501.

FOOT PROTECTION

The floor in a machine shop is often covered with razor-sharp metal chips, and heavy stock may be dropped on the feet. Therefore, safety shoes or a solid leather shoe must be worn at all times. Safety shoes are available in the supply system. These have a steel plate located over the toe and are designed to resist impact. Some safety shoes also have an instep guard.

GRINDING DUST AND HAZARDOUS FUMES

Grinding dust from abrasive wheels is made up of extremely fine particles of the metal and the wheel. Some grinding machines are equipped with a vacuum dust



collector. When operating a grinder without a vacuum, wear an approved respirator to avoid inhaling the dust. Whenever possible, use coolant when grinding. This will aid in dust control. Grinding dust can be very dangerous to your health, especially beryllium or parts used in nuclear systems. These materials require careful control of grinding dust.

Metals such as zinc give off toxic fumes when heated above their boiling point. Inhaling these fumes may cause temporary sickness, or death. The fumes produced from lead and mercury are very harmful, as their effect is cumulative in the body and can cause irreversible damage. When unsure of the materials being machined, it is advisable to wear a respirator.

For more specific information on respirator safety, refer to TBMED 502.

PROPER LIFTING PROCEDURES

Using improper lifting procedures may result in a permanent back injury. Back injury can be avoided if the correct lifting procedures are followed. When lifting heavy or large objects, get some assistance or use a hoist or forklift.

Objects within your ability can be lifted safely as long as the following procedures are followed:

Keep your back straight. Squat down, bending at the knees. Use the leg muscles to do the work and lift slowly. Do not bend over the load as this

will put excessive strain on your spine. Carry the object where it is comfortable, and pay close attention to where you are

walking and object around you. When placing the object back on the floor, use the same procedures as when it was

lifted.

ELECTRICAL SAFETY

Exposure to electrical hazard will be minimal unless the operator becomes involved with machine repair. The machine operator is mostly concerned with the on and off switch on the machine tool. However, if adjustments or repairs must be made, the power source should be disconnected. If the machine tool is wired permanently, the circuit breaker should be switched off and tagged with an appropriate warning statement. Most often the power source will not be disconnected for routine adjustment such as changing machine speeds. However, if a speed change involves a belt change, make sure that no other person is likely to turn on the machine while the operator’s hands are in contact with belts and pulleys.

SAFETY RULES FOR MACHINE TOOLS



Since different cutting tools and machining procedures are used on various machine tools, the safety precautions for each may vary. The following are general safety rules for any machine tool:

Gears, pulleys, belts, couplings, ends of shafts having keyways, and other revolving or reciprocating parts should be guarded to a height of 6 feet above the floor.

The guards should be removed only for repairing or adjusting the machine and must be replaced before operating it.

Safety setscrews should be used in collars and on all revolving or reciprocating members of the machine tool or its equipment.

Do not operate any machine tool without proper lighting. Never attempt to operate any machine tool until you fully understand how it works

and know how to stop it quickly. Never wear loose or torn clothing and secure long hair, since these items can become

caught in revolving machine parts. Ties should be removed and shirt sleeves should be rolled up above the elbow.

Gloves should never be worn when operating machinery except when absolutely necessary.

Always stop the machine before cleaning it or taking measurements of the workpiece. Do not lubricate a machine while it is in motion. Injury to the operator and damage to

the machine may result from this practice. Never remove metal chips, turnings, or shavings with your hands; they may cause a

serious cut. If the shavings are long, stop the machine and break them with pliers or a bent rod, and then brush chips off the machine. Remove cast-iron chips, which break into small pieces, with a brush. Never wipe away chips when the machine is operating.

Always wear safety glasses or goggles while operating machine tools. Also, wear respiratory protection if operation creates hazardous dust. All persons in the area where power tools are being operated should also wear safety eye protection and respirators as needed.

Know where tire extinguishers are located in the shop area and how to use them. Never wear jewellery while working around machine tools. Rings, watches, or

bracelets maybe caught in a revolving part which could result in the hand being pulled into the machine.

Avoid horseplay. Tools are very sharp and machines are made of hard steel. An accidental slip or fall may cause a serious injury.

Never use compressed air without a safety nozzle to clean machines or clothing. It will blow sharp, dangerous metal chips a long distance.

Keep the floor around machines free of tools, stock, oil, grease, and metal chips. Tripping over metal on the floor, especially round bars, can cause dangerous falls. Wipe up all oil, grease, and cutting fluid spills on the floor as soon as possible to prevent a fall. Metal chips are very sharp and can easily become embedded in the soles of shoes, making them very slippery, especially when walking on concrete floor.

Never place tools or other materials on the machine table. Cluttering up a machine with tools or materials creates unsafe working conditions. Use a bench or table near the machine for this purpose.

Always use a rag when handling sharp cutters such a smiling cutters and end mills. Do not expose power tools to rain or use in damp or wet locations. Always secure the work piece. Use clamps or a vise. It is safer than using your hands,

and it frees both hands to operate the tool



Do not abuse electrical cords. Never carry a tool by its cord or yank it to disconnect it from a receptacle. Keep electrical cords away from heat, oil, and sharp edges.

Have damaged or worn power cords and strain relievers repaired or replaced immediately.

Remove adjusting keys and wrenches. Form a habit of checking to see that keys and wrenches are removed from tools before turning them on.

Do not operate any machine tool while under the influence of drugs, alcohol, or any medication that could cause drowsiness.

Study of Machine Tools

Various machining purpose used these all type of mechanical machining machines are Lathe machine, Shaper machine, Slotting machine, Planning machine, Drilling machine, Boring machine, Milling machine, Grinding machine, Lapping machine Honing machine and Broaching machine

These machines are to producing various operations like namely Facing, Chamfering, Step turning, Taper turning, Plain turning, Knurling, Grooving, Thread cutting, Drilling, Tapping, Precision grinding, Cylindrical grinding, Surface grinding, grinding of tool angles e.t.c.

Lathe:



Fig 1. Center Lathe

A lathe s a machine tool which rotates the workpiece on its axis to perform various operations such as cutting, sanding, knurling, drilling, or deformation with tools that are applied to the workpiece to create an object which has symmetry about an axis of rotation.

SHAPER MACHINE:



Fig 2 Shaper machine

A shaper is a type of machine tool that uses linear relative motion between the workpiece and a single-point cutting tool to machine a linear tool path. Its cut is analogous to that of a lathe, except that it is linear instead of helical. (Adding axes of motion can yield helical tool paths, as also done in helical planning.) A shaper is analogous to a planer, but smaller, and with the cutter riding a ram that moves above a stationary workpiece, rather than the entire workpiece moving beneath the cutter. The ram is moved back and forth typically by a crank inside the column; hydraulically actuated shapers also exist.

PLANNING MACHINE:

A planer is a type of metalworking machine tool that uses linear relative motion between the workpiece and a single-point cutting tool to machine a linear tool path. Its cut is analogous to that of a lathe, except that it is linear instead of helical. (Adding axes of motion can yield helical tool paths; see "Helical planing" below.) A planer is analogous to a shaper, but larger, and with the entire workpiece moving on a table beneath the cutter, instead of the cutter riding a ram that moves above a stationary workpiece. The table is moved back and forth on the bed beneath the cutting head either by mechanical means, such as a rack and pinion drive or a leadscrew, or by a hydraulic cylinder.



Fig 3 Planer machine

DRILLING MACHINE:A drill or drill motor is a tool fitted with a cutting tool attachment or driving

tool attachment, usually a drill bit or driver bit, used for drilling holes in various materials or fastening various materials together with the use of fasteners. The attachment is gripped by a chuck at one end of the drill and rotated while pressed against the target material. The tip, and sometimes edges, of the cutting tool does the work of cutting into the target material. This may be slicing off thin shavings (twist drills or auger bits), grinding off small particles (oil drilling), crushing and removing pieces of the workpiece (SDS masonry drill), countersinking, counterboring, or other operations. Drills are commonly used in woodworking, metalworking, construction and do-it yourself projects. Specially designed drills are also used in medicine, space missions and other applications.



MILLING MACHINE

Fig 4Milling machine

A milling machine (also see synonyms below) is a machine tool used to machine solid materials. Milling machines are often classed in two basic forms, horizontal and vertical, which refers to the orientation of the main spindle. Both types range in size from small, bench-mounted devices to room-sized machines. Unlike a drill press, this holds the workpiece stationary as the drill moves axially to penetrate the material, milling machines also move the workpiece radially against the rotating milling cutter, which cuts on its sides as well as its tip. Workpiece and cutter movement are precisely controlled to less than 0.001 in (0.025 mm), usually by means of precision ground slides and lead screws or analogous technology. Milling machines may be manually operated, mechanically automated, or digitally automated via computer numerical control (CNC).



Fig 1: Hexagonal block



Ex No: 1 MEASUREMENT OF SHEAR ANGLEDate

Aim:

To measure the shear angle to the given conditions.

Tools and Equipments needed:

Lathe, Single point turning tool, Micrometer.

Procedure:

1. The workpiece is held in the chuck of lathe.2. The known depth of cut is given and cut is made on the workpiece uncut chip

thickness, (t1).3. The chip is taken for thickness inspection. And the mean chip thickness is

measured. (t2).4. Chip thickness ratio is calculated using the formula

rc=t 1t 2

5. For the given tool rake angle the shear angle is calculated using the formula

tanφ=rccos α

1−r csinα

6. The same procedure is repeated for few more thickness readings on the same chip and same mean shear angle is calculated.

7. The experiment is repeated for different depth of cut.

Measurement of Chip Thickness LC ____________



S.NoDepth Of Cut

t1 (mm)

Micrometer ReadingChip

Thicknesst2 = PSR +

HSR

Pitch scale reading

Head Scale Coincidence

(HSC)

Head Scale ReadingHSR =

HSC*LC1. 0.252. 0.253. 0.254. 0.25

5. 0.56. 0.57. 0.58. 0.5

Shear Angle calculation

S.NoUncut Chip Thickness t1

(mm)

Average shear angle

Chip Thickness t2

Chip Thickness ratio

r = t1/t2

Shear angle

1. 0.252. 0.253. 0.254. 0.25

5. 0.56. 0.57. 0.58. 0.5

Calculation



RESULT:

Thus the shear angle is found for different depth of cuts.

Workpiece no: Date of completion Staff signature Marks



Ex No: 2



Cutting force measurementDate

Aim:

To measure the cutting forces for given cutting conditions.

Tools Required:

Lathe, Lathe tool dynamometer, workpiece of any material.

Procedure:

1. The lathe tool dynamometer is initially set to zero reading.

2. The workpiece to be machined is ensured to have smooth surface and the tool tip coincides with centre height of workpiece. .

3. Insert the power cable into the 230V, 50Hz, A.C. Main supply.

4. Switch on the instrument by placing the power switch at ON position.

5. Set the switch at read position.

6. Turn back the read switch to read position in X, Y, Z to read the coordinate values.




Ex No: 3 Tool Wear measurement using Tool Maker’s microscope

Date

Aim:

To measure the flank wear of the given single point cutting tool using tool maker’s microscope.

Tools Required:

Tool maker’s microscope Micrometer attachment Single point cutting tool.

Procedure

The tool maker’s microscope is switched on.

The single point cutting tool is placed on the glass table.

Using the focusing wheel of the microscope the cutting tool is brought under proper focus.

One of the worn flank end is place on the reference line which is visible through the microscope.

The table movement is adjusted from one end of the flank wear to the other end using the micrometer.

From the micrometer reading, the length of the flank wear is noted down.



50 mm

6mm

3 mm

Φ25

50 mm



Ex No: 4 MACHINING AN INTERNAL KEYWAY USING SLOTTING MACHINE

Date

Aim: To machine an internal keyway in the given workpiece to the dimensions as shown in the figure using Slotting Machine.

Tools and materials required:

Slotting Machine, Scriber, Divider, Steel Rule, MS Square plate (50 x 50 x 6 mm)

Procedure: 1. The given workpiece is measured for its initial dimensions. 2. With the help of scriber mark the keyway dimensions in the workpiece. 3. Fix the workpiece in the vice of the slotting machine. 4. After fixing the workpiece and the slotting tool, allow the ram to vertically reciprocate.5. Start the slotting process by giving the required depth by horizontally moving the vice. 6. Slowly increase the depth of cut and repeat the procedure to make the required shape. 7. The workpiece is now checked for final dimensions.

Result: Thus, internal keyway is machined in the given workpiece to the dimensions as shown in the figure using Slotting Machine.




Before Machining

25 mm

Φ53

After Machining

40

40



Ex No: 5Cylinder to Square Block using PlanerDate

Aim

To machine the workpiece as the given drawing using planer machine.

Tools required:

Single point cutting tool

Double ended spanner

Parallel bar

Lever

Steel Rule

Try square

Vernier height gauge.

Materials required:

Aluminum round (Φ53 x 25 thick)

Procedure

The machine is cleaned and lubricated.

Raw materials size is checked.

Workpiece is fixed in machine vise along with parallels

Marking is done on the job as per given dimensions.

Adjust the stroke length according to job length.

Planning operation is done for required dimension using suitable depth of cut and number of passes.

Result: Thus, internal keyway is machined in the given workpiece to the dimensions as shown in the figure using Slotting Machine.




Ex No: 6Gear Milling in Milling machine.Date

Aim:

To make a spur gear on the given gear blank using horizontal milling machine.

Tools Required:

Double end spanner

Vernier Calliper

Gear tooth vernier.

Index plate.

Milling cutter.

Centre.

Mandrel

Universal Milling machine.

Materials Required.

Gear Blank (ϕ 180 mm)

ProcedureFollowing calculations are made for gear tooth dimensions:

Blank Diameter=(Z+2 )m

Tooth Diameter=2.2 .5m

Toothwidth=1.507m

Where Z = Number of teeth and

m = module

Following calculations are made for indexing

Index crankmovement=40z



Calculations

Gear Dimensions

Z = No. of teeth =

m = module = 2 mm

Blank Diameter = (Z + 2) m

=

=

Tooth Depth =

=

=

Indexing Calculation

= 40 / Z

=

=



Machine parts are cleaned and lubricated.

Raw material size is checked.

The dividing head and the tail stock are bolted on the machine table. Their axis must be set parallel to the machine table.

The given gear blank in fixed between head and tail stock with a mandrel.

Pitch, depth of cut, addendum, dedundum calculations are made and corresponding index plate is selected.

The cutter is mounted on the arbor. The cutter is centred accurately with the gear blank.

Suitable speed is selected and machined is switched on.

Feed is given by the linear movement of the table and it is raised till the periphery of the gear blank just touches the cutter.

The micrometer dial of vertical feed screw is set to zero in this position.

Then the table is raised further to give the required depth of cut.

The machine is started and feed is given to the table to cut the first groove of the blank.

The index plate is rotated for required rotation and the teeth are cut.

After the cut, the table is brought back to the starting position.

Then, the gear blank is indexed for the next tooth space.

This is continued till all the gear teeth are cut.

Result

Thus, the required gear is machined using the milling machine to the required number of teeth.




Ex No: 7Key way Cutting in Milling machineDate

Aim

To make a keyway on a workpiece as per the given drawing using vertical milling machine.

Tools Required

End milling cutter. Double end spanner. Parallel barLever. Steel Rule. Spanner. Try Square. Vernier Height gauge.

Materials:

MS square block (52 x 52 x 52 mm

Procedure.

The machine is cleaned and lubricated.

The raw material size is checked.

As per the given drawing markings are done on the workpiece.

The job is fixed on the milling machine using levers.

Keyway is cut on the job as per the dimensions giving a proper depth of cut.

Remove the job and clean the machine.

Result

Thus, keyway is cut on workpiece using milling machine.




Ex No: 8 Grinding to the required accuracy by surface grinding

Date

Aim:

To perform grinding operation in surface grinding machine.

Equipments and Tools required:

Steel Rule

Try square

Vernier Caliper.

Materials Required:

Mild Steel block (100 x 50 x 60)

Procedure:

The given work piece is taken and checked for its dimensions.The job is placed on the grinding magnet at opened position.Then each face is grinded to the required accuracy by

constant speed.The job is removed from the required accuracy. It is checked

by using vernier caliper and squareness is checked by using try square.

Result:Thus the square section is grinded to the required accuracy in grinding

machine.

Workpiece no: Date of completion Staff signature



Marks

Before Machining

After Machining



Ex No: 9Drilling, Tapping and ReamingDate

Aim:To drill and tap the workpiece as per the given dimensions using radial

drilling machine.

Tools Required:Drill bit. LeverSteel RuleSleeveVernier height Gaugeµ 12 x 1.75 tap.

Materials Required:MS (102 x 52 x 6 mm)

Procedure:The machine is cleaned and lubricated. The raw material size is checked. As per the given drawing markings are done on the workpiece. The workpiece is fixed on the drilling machine. The required drill bit is fixed in the spindle. Proper speed is set using gears provided. The operation is done by lowering the handle and starting the material

removal process. The job is removed from the drilling machine and is fixed in the vice. Suitable tap is selected and tapping is done. The workpiece is removed and inspected.

ResultThe operations are done on the given workpiece using radial drilling

machine as per the required dimensions.




Marks

Before Machining

After Machining



Ex No: 9Capstan and Turret latheDate

Aim

To drill, ream, Countersink on a given workpiece as per the drawing using capstan and turret lathe.

Tools RequiredSpanner

Drill Bit and Reamer

Steel Rule

Vernier Calliper.

Materials Required

MS Round rod dia 25mm x 60 mm

Procedure

The machine is cleaned and lubricated. The raw material size is checked. The job is fixed in the chuck using chuck key.

The single point cutting tool, start drill bit, ϕ10 mm drill bit, reamer tool, Countersink tool are fixed in the turret head.

Facing operation is done on the job using single point cutting tool.The turret head is indexed and start drill is made on job. The next tool is indexed and a hole of 10mm dia is drilled in the

workpiece. Next reaming tool is indexed and reaming operation is done on the

workpiece. Next a hole of 15mm dia is countersunk in the workpiece. The workpiece is removed from lathe.

Result:

Thus the object is made as per the given drawing from the workpiece.




Marks


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