enginerring mechanical 2nd yr 2nd sem lab manual

1. LIST OF EXPERIMENTS
1. Plain turning and step turning on lathe
2. Taper turning and knurling on lathe
3. Thread cutting and knurling on late
4. Spur Gear cutting on milling machine

2. LATHE JOB I
AIM: To perform the plain turning and step turning operation on a given work piece to get
the required product.
SKETCH:
WORK MATERIAL REQUIRED: MS Round rod of 25 mm Dia and 110 mm long.
TOOLS REQUIRED: Outside Callipers, Steel rule, Tool post spanner, Chuck spanner,
HSS Single point tool.
MACHINE TOOL SPECIFICATION:
Admit between center :
Length of the bed :
Centre height :
Swing overbed :
Swing on gap :
Spindle bore :
No.and range of speeds :
Lead screw :

3. SEQUENCE OF OPERATION:
1. Facing
2. Plain Turning
3. Step Turning
4. Chamfering
PROCEDURE:
1. The given workpiece is measured for its initial dimensions.
2. Facing is done to machine the end face of the workpiece.
3. Turning is done to reduce the diameter as shown in the figure.
4. Step turning is again done to reduce the diameter at particular position for particular
distance.
5. The workpiece is now checked for final dimensions.
PRECAUTIONS:
1. The work piece and the tool must be rigidly fixed.
2. The lathe should be started only after tightening of the chuck with the spanner and
removing the spanner
3. The center of the work piece must coincide with the lathe center, and the height of the
tip of the tools must coincide with the axis of the lathe centers.
4. Optimum machining condition must be maintained.
RESULT: the desired work is obtained by machining process on the lathe.
APPLICATIONS:

4. LATHE JOB II
AIM: To perform the plain turning and taper turning operation on a given work piece to
get the required product.
SKETCH:
WORK MATERIAL REQUIRED: MS Round rod of 25 mm Dia and 110 mm long.
TOOLS REQUIRED: Outside Callipers, Steel rule, Tool post spanner,Chuck spanner,
HSS Single point tool.
MACHINE TOOL SPECIFICATION:
Admit between center :
Length of the bed
Centre height :
Swing overbed
Swing on gap :
Spindle bore :
No.and range of speeds
Lead screw :
SEQUENCE OF OPERATION:
1. Facing
2. Plain Turning
3. Taper Turning

5. PROCEDURE:
1. The given workpiece is measured for its initial dimensions.
2. Facing is done to machine the end face of the workpiece.
3. Turning is done to reduce the diameter as shown in the figure.
4. Step turning is again done to reduce the diameter at particular position for particular
distance.
5. Taper turning is performed by swiveling the compound rest of the lathe.
The Swivel angle is determined by using the formula
PRECATIONS:
1. The work piece and the tool must be rigidly fixed
2. The lathe should be started only after tightening of the chuck with the spanner and
removing the spanner
3. The center of the work piece must coincide with the lathe center, and the height of the
tip of the tools must coincide with the axis of the lathe centers.
4. Optimum machining condition must be maintained.
5. Knurling must be done at low speeds.
6. Turning of use the work piece should be done before working on it
using a surface gauge.
RESULT: The desired work is obtained by machining process on the lathe.’
APPLICATIONS:

6. LATHE JOB III
AIM: To perform the plain turning,threading and knurling operations on a given work
piece to get the required product.
SKETCH:
WORK MATERIAL REQUIRED: MS Round rod of 25 mm Dia and 95 mm long.
TOOLS REQUIRED: Outside Callipers, Steel rule, Tool post spanner,Chuck spanner,
HSS Single point tool.
MACHINE TOOL SPECIFICATION:
Admit between center :
Length of the bed :
Centre height :
Swing overbed :
Swing on gap :
Spindle bore :
No.and range of speeds :
Lead screw :
SEQUENCE OF OPERATION:
1. Facing
2. Plain Turning
3. Kunurling
4. Chamfering
5. Thread Cutting

7. PROCEDURE:
1. Fix the job in the chuck and select a proper single point HSS tool and fix it in
holder of the tool post using an tool post spanner. With the help of a surface gauge
true the surface of the job.
2. Adjust the machine to run the job at required revolutions and obtain usual cutting
speeds for the specific tool/work piece.
3. Fix the job such that 70mm is outside the chuck and perform the facing
operation.
4. Now, perform the plain turning operation from the outer end to the groove till the
outer diameter is 23mm.
5. The length of 40mm is marked on the length of the job. Insert the Knurling tool in
the tool post and perform the knurling operation at a very low speed till the mark.
6. Reverse the job (removing from the chuck and fixing the other side) such that
65mm protrudes up outside the chuck and perform plain turning till a diameter of
23mm. Then mark 20mm from knurled end and perform plain turning till the mark
till outer dia is 18mm
7. Now, the machine is adjusted for thread cutting by the engagement of the half nut
lever.(Set the cross –feed dial to 0 –0 and give the depth of cut. After one cut is
finished all along the length move the cross dial to negative value and reverse the
tool to its initial position. Then again set the cross dial to 0-0 and give a higher
value of the depth of cut than the previous value.)
8. Repeat on the screw pitch gauge.
9. Chamfering is done on all the sharp edges.
PRECATIONS:
1. The work piece and the tool must be rigidly fixed
2. The lathe should be started only after tightening of the chuck with the spanner and
removing the spanner
3. The center of the work piece must coincide with the lathe center, & the height of the
tip of the tools must coincide with the axis of the lathe centers.
4. Optimum machining condition must be maintained.
5. Knurling must be done at low speeds.
6. Turning of use the work piece should be done before working on it
using a surface gauge.
RESULT: The desired work is obtained by machining process on the lathe.
APPLICATIONS:

8. SHAPING
AIM : To prepare a Hexagonal block of 25mm side 15mm thick from a given MS Round
block on a Shaping machine.
SKETCH:
WORK MATERIAL REQUIRED: MS Round block of 50mm Dia and 18mm thick.
TOOLS REQUIRED: Steel rule, Round nose HSS, Spring divider, Surface gauge,
shaping machine.
SEQUENCE OF OPERATION:
1. Marking
2. Setting the work
3. Adjustment of the stroke length
4. Adjustment of the Stroke position
5. Shaping
PROCEDURE:
1. The flat surfaces of the given MS Round rod are filled to make them smooth
and chalk applied over the surface. A Hexagon is marked using the spring divider
and the dot punch
2. The work piece is fixed on the vice of the work table such that the tool is just
above the surface, and with the help of the surface gauge the work piece is fixed
such that the side of the hexagon is parallel to the vice or the work table.
3. The stroke length is adjusted for the optimum machining time and the
dimensions of the work piece.

9. 4. The position of the stroke of the ram is adjusted so that there is sufficient gap
before starting the cut for giving the feed and finishing the cut.
5. The shaping of the job is done giving suitable depth of cut. After one side is
finished, the job rotated and the job is repeated for tall remainng 5 sides.
PRECAUTIONS:
1. The work piece should be marked accurately
2. Work piece should be positioned correctly in the vice such that the side of
the
hexagon is parallel to the vice, using a surface gauge.
3. The cross feed ad the depth of cut should be uniform
4. The work piece should be held tightly in the vice
RESULT :- A Hexagonal Block of 25 mm sides and 15mm thick is obtained.
APPLICATIONS:

10. SPUR GEAR ON MILLING
AIM:To cut an involute spur gear, 10mm thick having 2mm module &19 teeth on
milling machine.
PRODUCT SKETCH:
GEAR BLANK CALCULATIONS:
Addendum =1m=1(2mm)=2mm
Dedendum =1.25m=1.25 (2mm)=2.5
Gear tooth depth =h=Addendum + Dedendum =4.5mm
Gear blank diameter=m(T+2)=2(19+2)=42mm
WORK MATERIAL REQUIRED:
MS blank of 42mm diameter & 10mm thick
TOOLS REQUIRED:
Involute from gear cutter no: 6 with 2mm module,
Universal dividing head along with its accessories.
MACHINE SPECIFICATIONS:
MACHINE PARTICULARS:
Depth of cut = Gear tooth depth = 4.5mm
Speed of cutter = 35 m/min
Feed (longitudinal) = 4mm/min

11. Index crank movement = 40/T = 40/19 = 2.2/19 (or 2.4/38 or 2.6/57 etc)
Hence plain indexing method is to be adopted.
After machining each tooth space, the index crank is to be rotated through TWO
complete revolutions & TWO holes in the 19 holes circle of the index plate.
PROCEDURE:
1. The dividing head & tail stock are bolted on the table after setting their axes
perpendicular to the machine spindle.
2. The cutter is mounted on the arbor & is then centered accurately with the dividing
head spindle axis by adjusting the position of table in traverse direction.
The alignment of the cutter with the work axis is checked by raising the table.
[In that position, the center line of the cutter must touch the center point of
tailstock]
This assures the radial setting of cutter relative to the gear blank.
3. The work is held rigidly in the true chuck of dividing head. The work is supported
from tailstock end also.
4. The index plate with suitable number of holes is selected or bolted to the dividing
head. The positions of the crank pin & sector arms are adjusted.
5. Setting the depth of cut:-
First the table is raised till the cutter just touches the periphery of the work. Then
the table is raised to a height equal to the tooth depth.
6. The machine is started & the required longitudinal feed is given to cut the first tooth
space of the gear. The machine is supported.
7. At the end of the cut, the table is brought back, longitudinally, to the starting
position.
8. The work is indexed for machining the next tooth space.
Index crank is rotated through 2revolutions + 2holes in 19 holes circle]
9. Steps 6, 7 & 8 are repeated till all the gear teeth are obtained.
PRECAUTIONS:
1. Job must be secured tightly between centers of the indexing device.
2. Suitable machining conditions should be maintained.
3. Index crank must be rotated to the exact number of rotations.
RESULT:
APPLICATIONS:

12. SINGLE PIECE PATTERN
AIM: To make a mould for single piece pattern.
SKETCH:
WORK MATERIAL REQUIERD:
Single piece pattern block, Moulding Sand.
TOOLS REQUIRED:
Cope, Drag ,rammer , strike offbar, sprue pin , riser pin , vent rod gate cutter , trowels ,
lifter.

13. SEQUENCE OF OPERATION :
1.Sand Preparation
2.Preparation of Mould
3.Placing of Pattern
4.Preparation of Drag
5.Preparation of Cope
6.Making of Sprue & Riser
PROCEDURE :
1. The Drag is first placed upside down a moulding.
2. The drag is filled with moulding sand and rammed suitably by means of rammer.
3. After sand is rammed a strike off bar is used to remove the excess sand and the
surface is made half.
4. The drag is then turned over and cope is placed on it. The two flasks are held
together rigidly by means of pins.
5. The above procedure is repeated again after palcing the sprue pin and riser at right
place.
6. After proper ramming the sprue and riser are removed from cope, vent holes are
made using vent rod.
7. Now the cope and drag are separated and pattern is removed using draw spike from
drag.
8. With the help of gate cutter the runner is prepared in the casing.
PRECAUTIONS :
1. The Vent holes should not reach the pattern.
2. The Sprue and Riser should be removed very carefully.

14. 3. Never pour over wet ground.
RESULT :
Thus the required mould cavity box is obtained.