Machines Tools

 

 

 

Machines Tools

 

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Machines Tools

Questions and Answers
UNIT-1
1.What is a lathe?
Lathe is a machine, which removes the metal from a piece of work to the required shape &size
2.what is the various operations can be performed on a lathe?

  1. Turning                   6.  Thread cutting               11.  Grooving
  2. Facing                      7.  Drilling
  3. Forming                   8.  Boring
  4. Knurling                  9.  Recessing
  5. Chamfering             10.  Tapping

3.what are principle parts of the lathe?

Red, headstock, tailstock, carriage, crossslide, toolpost

4.what are the types of headstock?

Back geared type, all geared type

5.state the various parts mounted on the carriage?

Saddle, compoundrest, crossslide, tool post

6.what are the four types of tool post?

  1. Single screw
  2. Open side
  3. Four bolt
  4. Four way

7.what is an apron?
The integral part of several gears, levers clutches mounted with the saddle for moving the garriage along with lead screw while thread cutting

8.state any two specification of lathe?

  1. The height of centers from the bed
  2. The maximum length of the bed

9.list any four types of lathe?

  1. Engine lathe
  2. Bench lathe
  3. Tool room lathe
  4. Semi automatic lathe
  5. Automatic lathe

10.what is a semi-automatic lathe?
The lathe in which all the machining operations are performed automatically and loading and unloading of work piece, coolant on or off is performed manually
11.what is copying lathe?

The tool of the lathe follows a template or master through a stylus or tracer

12.state the various feed mechanisms used for obtaining automatic feed?

  1. Tumbler gear mechanism
  2. Quick change gearbox
  3. Tumbler gear- Quick change gearbox
  4. Apron mechanism

13.list any four holding devices?

  1. Chucks
  2. Centers
  3. Face plate
  4. Angle plate

14.what are the different operations performed on the lathe?
Centering, straight turning, rough turning, finish turning, shoulder turning, facing, chamfering, knurling, etc

 

15.define the term ‘Conicity’?

The ratio of the difference in diameters of tapers its length       k= D-d

                                                                            l                             
d-smaller dia
D-bigger dia
l-length of the work piece
16.state any two specifications of capston lathe & turret lathe?

  1. Number of spindle speed
  2. Number of feeds for the turret or saddle

17.compare the advantage of capston lathe & turret lathe?

  1. Heavier & larger work piece chucking can be done
  2. More rigid hence it withstand heavy cuts

18.what is tooling?
Planning of operations sequence & preparation of turret or capston lathe are termed as tool- layout or tooling
19.what are the three stage of a tool-layout?

  1. Planning & scheduling
  2. Detailed sketching of various machining operation sequence
  3. Sketching the plan showing various tools

20.what are the different drives used in copying lathe?

  1. Mechanical drives
  2. Air drives
  3. Hydraulic drives

21.what are the components that can be turned on a copying lathe?

  1. Cam shaft
  2. Crank shaft
  3. Journal bearings

 

UNIT-2

22.what is shaper?
The machine, which is having a reciprocating type of machine tool with a single point cutting tool, used to produce flat surfaces called as Shapers
23.list any four important parts of a Shaper?

Table, Tool head, Ram, Cross rail

24.How the feed  & depth of cut is given to the shaper?
Feed is given by rotating the down feed screws of tool head depth of cut is given by rotating by raising or elevating the table
25.mention any four-shaper specification?

  1. Maximum length of stroke
  2. Type of driving mechanism
  3. Power of the motor
  4. Speed &feed available

26.How the planer differs from the shaper?
In planner-the work reciprocate while the tool is stationary
In shaper-the tool reciprocate while the work is stationary
27.state the use of planer?
The planer is used for machining heavy & large casting Ex. lathe bed ways, machine guide ways
28.List the various types of planners?

  1. Double housing
  2. Open side planer
  3. Pit planer
  4. Edge planer
  5. Divided table planer

29.Name the various parts of a double housing planer?

  1. Bed
  2. Table
  3. Columns
  4. Cross rail      5. Tool head

30.Mention any four specification of planer?

  1. Maximum length of the table
  2. Total weight of the planer
  3. Power of the motor
  4. Range of speeds & feed available
  5. Type of drive required

31.What is ment by drilling?
Drilling is the process of producing hole on the work piece by using a rotating cutter called drill
32.What is gang -drilling machine?
When a number of single spindles with essential speed & feed are mounted side by side on one base and have common worktable is known as gang –drilling machine
33.Mention any four specification of drilling machine?

  1. Maximum size of the drill in mm that the machine can operate
  2. Table size of maximum dimensions of a job can mount on a table in square meter
  3. Maximum spindle travel in mm
  4. Number of spindle speed & range of spindle speeds in r.p.m.

34.List any four machining operations that can be performed on a drilling machine?

  1. Drilling
  2. Counter sinking
  3. Tapping
  4. Trepanning

35.What are the different ways to mount the drilling tool?

  1. Fitting directly in the spindle
  2. By using a sleeve
  3. By using a socket
  4. By means of chucks

36.what is broaching?
Broaching is a process of machining a surface with a special multipoint cutting tool called broach which has successfully higher cutting edges in a fixed path
37.Indicate any two specification of a broaching machine?

  1. Maximum length of stroke in mm
  2. Maximum force developed by the slide in tones

38. What are the advantages and limitation of broaching?
Advantages:

  1. Roughing, semi finishing & finishing cuts are completed in one pass of the broach
  2. Broaching can be used for either external or internal surface finish

Limitation:

  1. High initial cost of the broach tool compare to other tools
  2. Job work or batch work is not advisable due to the high tool cost.

39.What are the different operations that can be performed on a broaching machine?

  1. Broaching splines
  2. Broaching a key way

40.What is boring?
Boring is a process of enlarging &locating previously drilled holes with a single point cutting tool
41.What are the application of boring?
The boring machine is designed for machining large &heavy work piece in mass production work of engine frame, cylinder, machine housing etc
42.Specify the importance of jig boring machine?

  1. A jig boring machine is a precision boring machine used for boring accurate holes at proper center to center distances.
  2. The machining accuracy of holes produce by this machine tool lies with in a range of 0.0025mm.

43.State the purpose of grinding?

  1. To remove small amount of metal from work pieces & finish then to close tolerances.
  2. To obtain the better surface finish.

 

44.Define the term “grade” used in grinding wheel?
Grade or hardness indicates the strength with which the bonding material holds the abrasive grain in the grinding wheel.
45.What is meant by dressing &truing?
The process of loading &breaking away the glazed surface so that new sharp abrasive particles are again present to work for efficient cutting is called dressing.
 Truing is a process of trimming the cutting surface of the wheel to run true with the axis.
46.What is process of lapping?
Lapping is a surface finishing process used for producing geometrically accurate flat, cylindrical &spherical surfaces.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Unit3

47.What are the specifications of the milling machine?

  1. The table length &width.
  2. Number of spindle speeds &feeds.
  3. Power of driving motor.

48.Mention the various movements of universal milling machine table?

  1. Vertical movement-through the knee.
  2. Cross vise movement-through the saddle.

49.State any two comparisons between plain &universal milling machine?

  1. In plain milling machine the table is provided with three movements, longitudinal, cross&vertical. In universal milling machine in addition to these three movements, there is a forth movement to the table. The table can be swiveled horizontally & can be fed at angles to the milling machine spindle.
  2. The universal milling machine is provided with auxiliaries such as dividing head, vertical milling attachment, rotary table etc. Hence it is possible to make spiral, bevel gears, twist drills, reamers etc on universal milling machine.

50.What are the cutter holding devices?

  1. Arbors
  2. Adaptors
  3. Collets

51.List the various type of milling attachment?

  1. Vertical milling
  2. Universal milling
  3. High speed milling
  4. Rotary
  5. Slotting
  6. Rack milling

 

52.Write any ten nomenclature of plain milling cutter?
Body of cutter, cutting edge, face, fillet, gash, lead, land, outside dia, root dia, cutter angles.
53.What are the advantages of milling process?

  1. It does not require a backlash eliminator.
  2. Mild surface does not have built up edge.

54.what are the down milling processes?

  1. Cutter with higher rake angle can be used. This reduces power requirements.
  2. Cutter wear is less because chip thickness is maximum at the start of cut.

55.list out the various milling operations?

  1. Plain or slab milling.
  2. Face milling.
  3. Angular milling.
  4. Gang milling.
  5. End milling.
  6. Gear cutting.

56.What does term indexing mean?
Indexing is the process of dividing the periphery of a job into equal number of divisions.
57.what are the three types dividing heads?

  1. Plain or simple.
  2. Universal.
  3. Optical.

58.What is cam milling?
Cam milling is operation of producing cams in the milling machine by the use universal dividing head &a vertical milling attachment.
59.What are the different types of thread milling?

  1. Thread milling by single form cutter.
  2. Thread milling by multi form cutter.

 

60.What are the other forming methods for manufacturing gears?

  1. Gear cutting by single point form tool.
  2. Gear cutting by shear speed shaping process.
  3. Gear broaching.
  4. Template method.
  5. Gear milling using a formed end mill.

61.List the gear generating process?

  1. Gear shaping process.
  2. Gear planning process.
  3. Gear hobbing process.

62.Mention the applications of gear shaping process?

  1. Gear shaping used for generating both internal & external spur gears.
  2. Helical gears can also be generated using special attachments.

63.What are the limitations of gear hobbing?

  1. Internal gears cannot be generated.
  2. Hobbing process cannot be applied very near to shoulders.

64.What are the advantages of gear planning process?

  1. Any given model can be cut using a single cutter.
  2. It is a simple flexible &accurate method of generating gears.

65.List the various gear finishing processes?

  1. Gear shaving.
  2. Gear burnishing.
  3. Gear grinding.
  4. Gear lapping.

66.Mention the advantages &limitations of gear shaving process?
Advantage:
The process can be used for both internal & external gears.
Limitations:
This process is only applicable to unhardened gears.

 

67.What are the purposes of gear grinding process?

  1. To improve the surface finish of teeth.
  2. To increase the accuracy of the teeth.

68.What is gear lapping?
Gear lapping is also employed for hardened gear teeth by an abrasive action.

 

 

 

 

 

 

 

 

 

 

UNIT-4

69. Define  automatic lathes.
Automatic lathes or simply automats are machines tools in which all the operations required to finish off the work piece are done automatically without the attention of an operator.
70. State any four advantages of automatic lathes.
1. Mass production of identical parts.
2. High accuracy is maintained.
3. Time of production is minimized.
 4. The bar stock is fed automatically
71. What are the types single spindle automatic lathe?
1.   Automatic cutting off machine.
2.   Automatic screw cutting machine.
3.     Swiss type automatic screw machine.
72. State the purpose of providing lead cam in single automatic screw cuffing machine?
The turret slide travel is controlled by a lead cam. cam gives a slow forward and fast return movement to slide.
73. Mention the applications of single spindle automatic screw cutting machine.
It is used for producing small jobs, screws, stepped pins, pins, bolts etc.
74. What are the advantages of a sliding head automatic lathes?
The advantage of a sliding head automatic lathe is that long, slender work pieces can be machined with very good surface finish, accuracy and concentricity in sliding head autornatic lathes.
75. What are the four major parts of swiss type automatic lathes?

  1. Sliding headstock
  2. Cam shaft
  3. Tool bracket
  4. Auxiliary attachments

 

76.  State the advantages of Swiss type screw cutting machine

  1. Wide range of speed
  2.  Rigid construction
  3. Micrometer tool setting
  4.  Simple design of cams

77.  State the principle of multispindle automats.
The principle of the multispindle automate is that it has a tool slide working on the jobs on all spindles simultaneously.
78.Define cam controlled automats.
The operating mechanism for sliding, feeding are actuated by cams through levers and gears.
79.  What are the purposes of using cam?
1. To contol purposes in automats screw machine.
2. To control the movement of cross slide.
3. To provide uniform rate of feed to tool during machining.
                  4. Some time to clamp the parts.
80. How the transfer machines works?
A transfer Machine is an automatic machine. It indexes or transfers the work piece and its fixture, from station to station while many operations are performed on it
81. State the principle of transfer machines.
           A Transfer Machine is one where several machines are linked together mechanically, electrically or hydraulically.
82. Classify transfer machines.
      Transfer machines are of three basic types,
     1.   Rotary indexing table transfer machine
2.   Inline transfer machine.

  1. Drum type transfer machine.

 

83. What are three types of rotary systems in rotary indexing transfer machines?
           1. The machining heads located outside and around a circular table and operates at its periphery.
           2. The heads are fixed around a central column of the machine and operate the components located on the table below them.
3. The components are carried on platens, which are fixed on a drum rotating on a horizontal axis, and machine heads operate from the sides.
84. State the advantages of rotary transfer machines
1. A rotary transfer machine is very compact.
2. It is used in presses for peening over rivets, nut running heads for assembling nuts to screws.
             3. Electric brazing heads for assembly.
85  What are the, different machining operations performed on in‑line transfer machines?
Machining operations at each station may tapping, reaming, boring, counter boring, chamfering, countersinking, milling and grooving.
86. How drum type transfer machine differs from rotary table?
The components are being transferred around a circular path to work stations. They are radically Positioned around the path at equal distances. The table is replaced by a drum which is mounted on trunions so that the drum rotates about a horizontal axis.
87. What are the two types of transfer devices?
1.Rotary transfer devices
          2.Hydraulic transfer devices.

 

 

 

Unit-5

88.Explain the cutting shaping process?
The required shape of metal is obtained by removing the Unwanted material from the work piece in the form of chips is called cutting shaping. Ex: turning, drilling, milling, boring, etc
89.Mention the various parts of single point cutting tool?

  1. Shank
  2. Face
  3. Flank
  4. Base
  5. Nose
  6. Cutting edge

90.What is tool signature?
The various angles of tools are mentioned in a numerical number in particular order. that order is known as tool signature.
91.What is effect of back rake angle &mention the types?
Back rake angle of tool is increases the strength of cutting tool& cutting action. It can be classified in to two types

  1. Positive rake angle
  2. Negative rake angle

92.What is side rake angle & mention its effects?
The angle between the tool face & the line parallel to the base of the tool. it is used to control chip flow
93.What are all the conditions for using positive rake angle?

  1. To machine the work hardened materials
  2. To turn the long shaft of small dia

94.When will the negative rake angles be used?

  1. To machine high strength alloys
  2. The feed rates are high

 

95.Define orthogonal & oblique cutting?
Orthogonal cutting:
The cutting edge of tool is perpendicular to the work piece axis.
Oblique cutting:
The cutting edge is inclined at an acute angle with normal to the cutting velocity vector is called oblique cutting process
96.What is cutting force?
The sheared material begins to flow along the cutting tool face in the form of small pieces. The compressive force applied to form the chip is called cutting force
97.What is chip thickness ratio?
The ratio of chip thickness before cutting to chip thickness after cutting is called chip thickness ratio.
Chip thickness ratio, r=t1=l2
t2   l1
98.What are the purposes of chip breakers?
The chip breakers are used to break the chips in to small pieces for the removal, safety & to prevent to machine & work
99.Define machinability of metal?
Machinability is defined as the ease with which the material can be satisfactorily machine.
100.What are the factors affecting the machinability?

  1. Chemical composition of work piece material.
  2. Microstructure of work piece material

101.what is machinability index?
It is the comparison of machinability different material to standard material. US material standards for 100% machinability are sae1112 hot rolled steel.
Machinability index I=Cutting speed of metal investicatedfor 20 minutes tool life
                                       Cutting speed of standard steel for 20 minutes tool life

 

102.How tool life is defined?
Tool life is defined as time elapsed between two consecutive tool resharpening. During this period tools serves effectively and efficiently.
103.What are the factors affecting tool life?

  1. Cutting speed
  2. Feed & depth of cut
  3. Tool geometry
  4. Tool material

104.Express the tailor’s tool life equation?
Tailors tool life equation:
                               VTn=C
                                          V=Cutting speed in m/min
                                          T=Tool life in minutes
                                          C=Constant
n=Index depends upon tool & work.
105.What is the function of cutting fluids?

  1. It is used to cool the cutting tool & the work piece.
  2. It improves the surface finish as stated earlier.
  3. It causes the chips to break up into small parts.
  4. It protects the finish surface from corrosion.
  5. It prevents the corrosion of work & machine.

106.What are the properties of cutting fluid?

  1. High heat absorbing capacities.
  2. It should have good lubricant properties.
  3. High flash point.
  4. It should be odourless.
  5. It should be non-corrosive to work & tool.

107.What are causes of wear?
The tool is subjected to three important factors such as force, temperature and sliding action due to relative motion between tool and the work piece. So the tool is wear easily.

 

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