Lathe, Drilling, Milling & Grinding, turning, facing, tread cutting, tapping, down milling, up milling, cylindrical grinding, center less grinding, end milling, slotting
3. Introduction to Lathe
• The commonly used general purpose lathe in workshop is engine lathe
• Major parts of lathe are as follows
• Bed
• Tail Stock
• Head Stock
• Carriage
• Lead Screw
• Cross slide
• Compoundrest
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5. Bed
• Bed is the foundation of all the machine & supports to all parts
• It consists of inner guide ways and external guide ways on which the head
stock and tail stock is mounted
• Guide ways maintain the allignment of the tail stock and head stock
• Bed is made up of cast iron
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6. Tail Stock
• Tail stock is also called as dead centre
• The main function of the tail stock is to hold the work piece at
the other end
• It mainly holds the spindle and drill tool
• Made up of cast iron
• It is mounted loosely on the guide ways and locked where ever
required
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7. Head Stock
• Head stock consists of all the gears and pullleys
• The main spindle is projected out from the head
stock
• It consists of spindle, chuck , back gear and pulley
system
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8. Compound
rest
• It is mounted on cross slide and supports to the
tool post
• It can be tilted through an angle to produce the
tapers
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9. Carriage
• It support the tool and slides over the bed
ways between tail stock and head stock
• Parallel feed are obtained by moving the
cariage
• It holds compound rest and tool holder
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10. Lead Screw
• It is a screw rod which runs ongitudinal in the
lathe
• It is engaged at the time of thread cutting and
other operations
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11. Specification of lathe
Swing is the largest work diameter which can be swung for the lathe bed.
The distance between tailstock and headstock center.
Bed length of the machine in a meter ( m ).
The lead screw of the pitch.
The horse power of the machine.
Number of speed of HS spindle and speed range.
The machine weight in a tone.
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12. Principle
of working
of lathe
It holds the work between two supports so call as centers.
Face plate or Chuck are using for holding the work.
Face plate or Chuck are mounted on the machine spindle.
The cutting tool is holding with the help of Tool post.
The movement of the job is rotating about the spindle axis.
Against the revolving work, the tool is feed.
The tool moves either parallel or inclination to the work axis.
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15. Cylindrical
turning
• It is the operation performed to remove the excess
material from the workpiece to produce a cylindrical
work surface
• The work piece is supported between the two centres
• The movement of the tool and work piece is parallel to
each other and perpendicular to work piece
• The cut materialwill come in the form of chips
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16. Cylindrical turning
• Turning is the operation of reducing the diameter of
a work piece to produce a cone -shaped or a
cylindrical surface as shown in fig. above.
• A simple single point cutting tools are use for
turning operations.
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17. Facing
• Facing is the operation for generation of flat surface
• In this one end of the work piece is fixed in the chuck and the other end
is kept free and the tool is moved over the free end surface
• Facing is an operation of reducing the length of a work piece to produce a
flat surface square with the axis.
• A regular turning tool may also be using for facing a large work piece.
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19. Thread
cutting
• Threading is a operations to produce a helical groove on a cylindrical or conical
surface by feeding the tool longitudinally when the job is revolvedbetween center’s
or by a chuck.
• Threads can be produced either on internal or external surface of a cylindrical bar.
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21. Taper turning
• Taper turning is the method to produce the conical surface on the workpiece
• Swivelling compond rest method
• In this method the compond rest is tilted to an angle to get the required taper angle
• The tool axis is tiled to an angle to get the taper angle
• Tail stock set over method
• In this method tail stock is tilted to an angle to get the required taper angle
• The work piece axis is tiled to an angle to get the taper angle
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25. Principle of
Drilling machine
• A spindle which turns the tool (called drill) which can
be advanced in the workpiece either automatically or by
hand.
• A work table which holds the workpiece rigidly in
position.
• Working principle: The rotating edge of the drill exerts a
large force on the workpiece and the hole is generated.
The removal of metal in a drilling operation is by
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27. Radial Drilling Machine
• Base: The base is a heavy casting that supports the machine structure; it provides rigid mountingfor thecolumn and stability for the
machine. The base is usually provided with holes and slots which help to Bolt the base to a table or bench and allow the work-holding device
or the workpiece to be fastened to thebase.
• Column:The column is a vertical post that Column holds theworktable and the head containing thedriving mechanism. The column may be
of round or box section.
• The table, either rectangularor round. Drill machine/press in shape supports the workpiece and is carried by the vertical column. The surface
of the table is 90-degree to the column and it can be raised, lowered and swiveled around it. The table can be clamp/hold therequired the
workpiece. Slots are provided in most tables to allow the jigs, fixtures or large workpieces to be securely fixed directly to the table.
• Drilling Head: The drilling head, mountedclose to the top of thecolumn, houses the driving arrangement and variable speed pulleys. These
units transmit rotary motion at different speeds to the drill spindle. The hand feed lever is used to control thevertical movement of the
spindle sleeve and thecutting tool.
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29. Twist drill and its nomenclature
• Body: The body of the twist drill spiral grooves cut on it. These grooves serve to offer clearance to the chips formed at the
cutting edge. They also permit the cutting fluid to spread to the cutting edges.
• Shank: It is a part that gets fitted into the drill chuck or sleeve. It might be parallel shank or taper shank. Smaller diameter
drills have straight shank. Morse taper is generally provided for large diameter tapered drills. The taper shank brings the
tang at the end of shank. This fits into a slot in the machine spindle, sleeve or socket and gives a positive grip.
• Neck: It is the undercut portion between the body and the shank. Usually, size and other details are marked at the neck.
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30. Twist drill and its nomenclature
• Point: It is the cone fashioned end of the drill. The point is shaped to produce lip, face, and flank and chisel edge or dead center.
• Land or Margin: It is a narrow strip. It ranges back on the edge of the drill flutes. The size of drill is measured across the lands at
the point end. Land retains the drill aligned.
• Web: It is the central portion of drill located between the roots of the grooves and lengthening from the point towardsthe shank.
• Chisel edge: The intersection of flank forms the chisel edge. This acts as a flat drill. It cuts a small hole in the work piece at the
beginning. Therefore cutting edges removes further materials to complete the hole.
• Cutting edge: The cutting edges of a drill are known as lips. Both lips should have equal length, same angle of inclination and
correct clearance.
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32. Boring
• Boring is a cutting process that involves the use of a
single-point cutting tool or boring head to enlarge
an existing hole in a workpiece. While drilling is
performed to create an initial hole in a workpiece,
boring is performed to enlarge an existing hole in a
workpiece.
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33. Reaming
• Reaming is a cutting process that involves the use of
a rotary cutting tool to create smooth interior walls
in an existing hole in a workpiece. The rotary cutting
tool used in reaming is known as a reamer.
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34. Tapping
• Tapping is a machining processfor producing internal
threads.
• TAPPING is a machining process for producing internal
threads.
• A tap is a cylindrical or conical thread-cutting tool
having threads of a desired form on the periphery.
Combining rotary motion with axialmotion, the tap cuts
or forms the internal thread.
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35. Milling machine
• Milling is a process of cutting or removing metal from a job by giving a feed. With single or multiple cutting edges.
• The number of cutting edges removes the material in a small amount from a job. This process is utilized to produce a flat
surface or curved surface or many other complex shapes with high accuracy and better surface finish.
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36. Principle of milling machine:
• The workpiece is placed on the work table. The cutting tool is also known as a cutter which rotates is to rotate to cut
the material. the cutter moves from right to left to remove the material from the workpiece. Due to the workpiece
advance, the cutter teeth remove the material from the workpiece for the desired shape.
• Both tool and workpiece will be rotating.
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37. Down milling
• The workpiece mounted at the table is moved in the identical path as that of the rotation of
the Milling cutter.
• The slicing force is maximum at the beginning and minimum on the give-up of cut.
• The Chip thickness is extra at the beginning of the reduction. The workpiece is not disturbed due
to the
• A chunk of the cutter on the work. The coolant at once reaches the slicing point. So the first-class
of
• The floor end received is high. Because of the backlash blunders among the feed screw of the
table And the nut, vibration is set up on the workpiece.
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38. Up milling
• On this approach, the workpiece mounted at the desk is fed against the route of
rotation of the
• Milling cutter. The cutting force is minimum at some stage at the beginning of the
reduction and maximum at the cease of reduction.
• The thickness of the chip is more at the give up of the reduce. Because the slicing
pressure is directed upwards, it tends to boost the workpiece from the fixtures.
• An issue is felt in pouring coolant on the cutting edge. Due to these motives, the
great of the floor acquired by using this method is wavy. This strategy being safer
is usually used and once in a while referred to as conventional milling.
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39. Up milling and Down milling
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41. Plane milling
• Plane milling: plane milling is also known as slab milling
or surface milling. This technic of milling flat surfaces
with the axisof the slicing tool parallels the surface
being machined.
• The rotating milling cutter provides continuous reduction
but moves from one side of the workpieceto some
other quiet. This process is as shown in the figure below.
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42. End milling
• End milling: in this operation flat surface is produced as well as slots
pockets, keyways are created in the workpiece. The tool moves to the right
angle to the axis of the rotating cutter.
• The tool has cutting edges at the end as well as the periphery.
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43. Slotter
• slotter is a milling operation in which groove or slots
are made in the workpiece.
• It has cutting edges on the periphery on both sides
of the tool.
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47. Grinding machine
• Grinding is a metal removal operation by means of abressive particles which are rigidly mounted on the rotating wheel
• Each abrasive particle acts as a single point cutting tool
• Grinding wheel is a multipoint cutting operation
• Grinding operation is perfomed to remove very less material normally grinding is performed for finsihing operation
• Abrasives used are Silicon carbide, boron carbide, alumnium oxide and cubic boron nitride etc.
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49. Cylindrical
grinding machine
Working Principle: The work piece is held between two centres
and the rotatinggrinding wheel is feed against it, this removes
the material and imparts the goodsurace finish
• The work must be constantlyrotated
• The grinding wheel must be contantlyrotated
• The grinding wheel is feed towards or away from the work
material
• Either the work or grinding wheel shld transvers each other
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50. Centreless grinding
machine
• Working Principle: The work piece is placed between two wheels
on the rest plate, wheels will roatate in clock wise direction where
as workpiece will rotate in counter clock wise directon
• Grinding wheel removed the material from work piece and
regulating wheel will guides the work piece
• Centre less means work piece is not held in between the centres
• Centreless grinding is a outside diameter grinding process
• The workpiece is not mechanically constrained while machining
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51. Thank you....
By:
Siddesh Kumar N M
Assistant Professor
Department of Mechanical Engineering
PES College of Engineering
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