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517

MANUFACTURING TECHNOLOGY

October 2019

PART – A

1. Write lathe specification

(Diagram = 1 mark

Explanation = 1 mark)

2. What are the uses of quick return mechanism

Generally the cutting operation only in the forward stroke, and backward stroke is

ideal and therefore wastage. In order to minimize this wastage the return stroke should be

completed as quickly as possible.

3. What is countersinking operation?

To extend a holes face area in a tapered profile is called counter sinking. This

Operation is aimed to seating a screw with tapered head.

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(Diagram = 1 mark

Explanation = 1 mark)

4. What is up – milling and down milling?

Up milling – it is the process of removing metal by a cutter rotated against the direction

of travel of the work piece. Here the cutting takes place when the cutter moves upward. this

method is also called “Conventional Milling”.

Down milling – it is the process of removing metal by a cutter rotated in the same

direction of travel of the work piece. Here the cutting takes place when the cutter moves

downward. this method is also called “Climb Milling”.

(Diagram = 1 mark

Explanation = 1 mark)

5. How broaches are classified?

1. According to the method of operation

(a) Push broach (b) Pull broach

2. According to the kind of operation

(a) Internal broach (b) External broach

3. According to their construction

(a) Solid broach (b) Over lapping teeth broach (c) Built up of replaceable section

(d) Inserted tooth broach (e) progressive cut broach

4. According to the function,

Key way, surface, round hole, spline, spiral, burnishing broach etc.

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6. Differentiate ECM and EDM

Sl.no ECM EDM

1. Electro chemical machining Electrical discharge machining

2. Machining done by chemical attach Machining done by high voltage spark and

arc

3. Chemical etchant used to chemical metal

removal

Tool cathode, work piece anode. Dielectric

fluid used.

7. Define accuracy.

Accuracy is degree of alignment of true value and measured value.

8. Write the purpose of dressing of grinding wheel

Removal glazing and loading from a grinding wheel is the purpose of dressing.

(Diagram = 1 mark

Explanation = 1 mark)

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PART – B

9. Describe any four types of shaping tools

1. Round nose tool

This type of tool is used for roughing operations. It may have side rake angle

between 100 to 20

0 and a side clearance angle between 2

0 to 4

0. This tool is of two types

namely, plain tool and bent tool. The plain tool is used for machining vertical surfaces.

Both the left hand and right hand types are available for this tool.

2. Square nose tool

This type of tool is used for finishing operations. The cutting edge of the tool may

have different widths. This tool can also used for machining the bottom surfaces of

grooves and key ways.

3. Side tool

Side tool is used for machining t-slots and narrow vertical surfaces. Both the left

hand and right hand types are available for this tool.

4. Parting off tool

This tool is used for cutting narrow slots and parting off the work piece. It has a

back rake angle of 30 and a side clearance angle 3

0

(Diagram = 1 mark

Explanation = 2 mark)

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10. Sketch planer work holding devices

(any three)

11. Write short notes on indexing of milling.

Indexing is equally dividing the periphery of circular workpiece for cutting gear

teeth for indexing dividing heads are used.

Methods of indexing:-

1. Direct indexing

2. Plain indexing

3. Compound indexing

4. Differential indexing.

1. Direct indexing

This method of indexing is used for small number of divisions in many identical

work pieces. This indexing can be done in both plain & universal dividing head spindle.

It has 24 equally spaced slots. A spring loaded pin is pushed into any one of the

holes to lock the spindles with the body while indexing.

2. Plain indexing

This indexing method is used for divisions that could not be indexed by direct or rapid

indexing. The universal dividing head is used for indexing. The dividing head spindle is

rotated by turning the index crank.

One complete turn of the index crank will make the spindle to turn 1/40th

of a

revolution.

For indexing a fraction of turn, an index plate having the suitable whole circle can

be used.

3. Compound indexing

This method is not used in practice. However this for academic interest, When it

Is not possible to divide the work piece by simple indexing, compound indexing method

is used

4. Differential indexing.

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This method of indexing is used for divisions that could not be indexed by simple

indexing by simple indexing. In differential indexing the required divisions on the work

piece is obtained by a combination of two movements

1. The index crank movement as in simple indexing.

2. The simultaneous movement of the index plate when the crank is turned.

12. What is truing of grinding wheels?

Truing is the process of changing the shape of the grinding wheel as it becomes

worn from an original shape, owing to the breaking away of the abrasive and bond. This

is done to make the wheel true and cancentric with bore or to change the face contour for

form grinding.

(Diagram = 1 mark

Explanation = 2 mark)

13. Describe the principle of broaching machine.

The work piece is set on the table by means of fixture. The broach is moved over

the surface in a fixed path. The broach has multiple cutting teeth along its length. The height of

tooth is gradually increasing. Each tooth removes a very small amount of metal.

The total metal removing is done progressively by each teeth. The machining is

done in one stroke of broach. The broach may be pulled or pushed over the surface of work

piece.

14. Write short notes on tolerance and surface finish

1. Surface finish – we cannot prodce any parts perfect smooth. There may be some

irregularities (hills and valleys) this is called surface texture or surface finish.

Surface finish is depend on following

1. Material

2. Machine tool

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3. Manufacturing processes

4. Cutting tool

5. Feed, speed & depth ct

6. Vibrations etc.

2. Tolerance –1. the permissible variation in size.

2. The difference between maximum limit and minimum limit

15. Write a note on plasma arc machining.

A gas has been heated to a high temperature (28000o C) to become partially

ionized and therefore electrically conductive. Plasma are maching is a thermal energy process. It

is done with a high speed jet of high temperature plasma.

16. Describe the nomenclature of drill.

1. Body

It is the main part of the drill. It has spiral flutes cut on it.

2. Shank

It is the part that fits into the machine spindle or any other holding device. The

shank may be tapered or straight. Morse taper is used for taper shank.

3. Tang

it is the flattened end of taper shank. It fits into the drift slot in the machine

spindle. The drill bit gets the drive from the spindle through the tang

4. Lip or cutting edge

It is the edge which actually cuts the material . There are two cutting edges. They

are equally inclined at 590 with the drill axis for general work.

5. Flutes

These are the helical grooves cut on the body of the drill. The function of flutes

are

1. To form the cutting edges on the point.

2. To make the chips to curl

3. To allow chips to escape

4. To allow cutting fluid to reach the cutting edge.

6. chisel edge or dead centre

This act as a flat drill. It cuts a small hole in the workpiece. Then the cutting

edges remove further material to complete the hole.

7.land

It is the narrow surface ground on the edge of the flutes. It is also called as

margin. Drill is full size only across the lands at the point end. The drill is aligned with the help

of land.

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8.Neck

It is the undercut portion between the body and the shank. Generally the size and

othe details of the drill are marked at the neck.

9. Point angle

It is the angle between the cutting edges. It is generally 1180. To cut harder

material layer angle are used

(any three)

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PART – C

17.(a) Explain the construction of double housing planner

(Diagram = 5 mark

Explanation = 5 mark)

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17.(b) Explain about the construction of shaper with neat sketch

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(Diagram = 5 mark

Explanation = 5 mark)

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18.(a) describe the various types of drilling operation

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(Diagram = 5 mark

Explanation = 5 mark)

18.(b) Briefly explain the various types of milling operation

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(Diagram = 5 mark

Explanation = 5 mark)

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19.(a) Explain surface grinding machine with neat sketch

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(Diagram = 5 mark

Explanation = 5 mark)

19.(b) Briefly explain vertical broaching operation

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(Diagram = 5 mark

Explanation = 5 mark)

20.(a) Explain the working of abrasive water jet machining

High pressurized water with abrasive particle is focused by nozzle an job and metal removal has

done. This type of process is called abrasive water jet matching.

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Main parts

1. Intersifier pump

2. Nozzle with work table movement

3. Regulating of mixing chaatimber

4. Filteration unit

Working method

The intensifier increases the water pressure and taken to the mixing chamber and mixed with

abrasive particles and also regulated and taken to nozzle to derive level of pressure as per job’s material

of derived speed of metal removal.

The very high pressurized water with abrasive particles kinetic energy is converted to pressure

energy and become stress and also metal removal takes place on work piece.

Process details

1. Work done is an the process erosion.

2. Pressure of water may be 1500 to 4000 N/m2

3. Nozzle is made by sintered diamond or tangton carbide.

4. Very hard materials also easilymachinable by this process.

(Diagram = 5 mark

Explanation = 5 mark)

20.(b) Describe working of electron beam machining

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Principle

The ions are bombard an slots surface. The bombard ion are insist atom of job to

moving.

Construction of working principle IBM

This equipment having a electron gun which is filled by argon gas. The gas molecules as

ionized by electrons. The electron gun is placed on a vaccum chamber which has argon gas.

The other names of this IBM is ion etching and ion polishing.

Advantages of EBM

1. Easy to control of metal removal rate.

2. No chemical etchant

3. No under cut

4. No need of etchant.

Advantages of EBM

1. To produce computer memories

2. To make wire dies.

3. Advantages of EBM

(Diagram = 5 mark

Explanation = 5 mark)

21.(a) Briefly explain optical measurement.

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(Diagram = 5 mark

Explanation = 5 mark)

21.(b) Explain uses of sine bar and slip gauges in angle measurement.

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(Diagram = 5 mark

Explanation = 5 mark)

PREPARED BY

K.SARAVANAPERUMAL,

LECTURER / ROBOTICS

222, APPC, PALANI