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JT POOE
200625055
THEORY OF MACHINE EXPERIMENT (1-B & 2-B)
OBJECTIVE
To draw the displacement diagram base on calculated theoretical values and compare them to thedisplacement against rotational angle obtained through experiment for a flat-ended follower.
APPARATUS
Fig. 1 Front View of Apparatus
The following experiment was based on the flat-ended follower and a curve cam.
Hard springwith a spring constant of 5026 N/m and a pre-compression of 8 mm.
10-additional
disc weights
20
Lower nut
5-Recording drum
12-Return spring
13 Tappet
14-Interchangeable
pick-up (flat or
cylindrical)
16-Belt drive for the
recording drum
21nuts fixing
the cross bar
18-Lifting spindle
11-Spacing discs
22cross bar
24- knurled nut
fixing the cam
23- fixing screw
5/24/2018 CAM Experiment
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JT POOE
200625055
THEORY OF MACHINE EXPERIMENT (1-B & 2-B)
Fig 2- Reading Drum
Fig 2 - SPEED CONTROLLER
1. Variable speed motor,speed range between 60 and 670 rpm, power
2. Dual bearing drive shaft;
3. Protective cover for the moving parts
4. Emergency stop button;
5. Recording drum powered by the drive shaft via the belt drive at a transmission ratio o
1:1
Switch for the electric motor
Potentiometer for
speed adjustment
Speed indicator
16-Belt drive for therecording drum
6-Recording pen
5-Recording drum
covered in wax-coated
paper (indicator paper)
17-Cross-bar mechanism
driving the recording pen25-Grip nut
5/24/2018 CAM Experiment
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JT POOE
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THEORY OF MACHINE EXPERIMENT (1-B & 2-B)
6. Recording pen is driven directly by the tappet via a crossbar
7. Probe for the recording
8. Speed sensor
9. Centrifugal mass to minimase rotationsl movement discontinuity at low speeds;
10.Additional disc weights that can be attached to the tappet upper end to increase th
moving mass
11.Spacing discs for spring pre-compression
12.Tappet guided by two maintenance free slide bearing sleeves13. Interchangeable pick-up (flat or cylindrical follower) fixed to the lower end of the tappet
14. Interchangeable cam
15.Belt drive for the recording drum
16.Cross-bar mechanism driving the recording pen.
17.Lifting spindle
18.Upper nut
19.Lower nut
20.Nuts fixing the cross bar
21.Cross bar fixing the return spring
22.Fixing screw for the interchangeable follower 14
23.Knurled nut for fixing the interchangeable cam 15
24.Grip nut
PROCEDURE
1. sRemove the knurled nut 24 and mount the circular cam 1 as shown in figure 11.
2. Attention to the front and rear view position of the cam as the cam guiding rod bore hole
situated on the rear of the cam.
3. Loosen the fixing screw 23 with the provided Allan key and insert the flat tappet followeApply a thin film of grease to the flat tappet.
4. The washer between the follower and tappet must be reinstalled in the same position durin
assembly.
5.
6. Take one sheet of wax-coated paper. Do not bend the paper or insert it with its recordin
side facing down, hold the paper by its edges with your fingertips. Handle the wax-coate
paper with care as its surface is very sensitive to scratches. Fold the narrow edge o
the paper 1012 mm back
7. From the graph obtained in the experiment, use it to draw a displacement diagram.
8. Connect the motor to the control unit.
9. Set the speed to 110 RPM.
10. Compare the calculated value with the measured results and prove that: given the sam
stroke and opening angle.
11. Using the designated set of formulae for each type of cam, draw a graph representing the
velocity against the rotation angle. Choose an increment of 100for the rotation angle.
5/24/2018 CAM Experiment
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JT POOE
200625055
THEORY OF MACHINE EXPERIMENT (1-B & 2-B)
Cam 2 (circulararc cam)
Base radius R = 25 mm;
Curved flank radius = 96.21 mmNose radius r = 10 mm
Maximum lift (cam stroke) h = 15 mmTotal angle of action 2 x = 140
0
Angular Velocity = 11.52 rads/s
d
R
h
r
CALCULATIONSFLANK
Formulae x= ( R)(1-Cos )
@ 0
0
@ 100
@ 200
NOSE:
Formulae Used was
@ 300
@ 400
@ 500
@ 600
@ 700
5/24/2018 CAM Experiment
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JT POOE
200625055
THEORY OF MACHINE EXPERIMENT (1-B & 2-B)
VELOCITY ON FLANK:@ 0
0
Formulae used
@ 100
@ 20
0
@ 300
VELOCITY ON NOSE:Formulae Used @ 30
0
@ 400
@ 500
@ 600
@ 70
0
ACCELERATION ON FLANK:Formulae used
@ 00
@ 100
@ 200
@ 30
0
ACCELERATION ON NOSE:
Formulae used @ 300
@ 40
0
@ 50
0
@ 60
0
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JT POOE
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THEORY OF MACHINE EXPERIMENT (1-B & 2-B)
@ 700
GRAPHS
0
2
4
6
8
10
12
14
16
0 10 20 30 40 50 60 70 80
Displacement(mm)
Rotational Angle(Degrees)
Displacement vs Angle
70, 00
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0 10 20 30 40 50 60 70 80
Velocity(m/s)
Rotational Angle(Degrees)
Velocity vs Angle
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THEORY OF MACHINE EXPERIMENT (1-B & 2-B)
EXPERIMENT 2-B
OBJECTIVE
To draw the displacement diagram based on the experiment values obtained through experiment
(2-B). To compare the displacement diagrams obtained through 1-B and 2-B experiments
-6
-4
-2
0
2
4
6
8
10
12
0 10 20 30 40 50 60 70 80
Acceleration(m/s2)
Rotational Angle(Degrees)
Acceleration vs Angle
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THEORY OF MACHINE EXPERIMENT (1-B & 2-B)
As it is seen from the graph the maximum lift of the graph occurs at 600which it is rotating a
an angular velocity of 350RPM. The maximum lift value occurred at 34.5mm to the carbon
paper then I had to divide it by 2.23 to get a maximum lift of 15.4mm.
DISCUSSION AND CONCLUSSION
I obtained the graphs by using the formulae for curve flank cam by taking into consideration theflank calculations and nose calculation. The results that I have obtained gave me similar graphs ofdisplacement, velocity and acceleration as illustrated from the theory of machines textbook. Thecalculated values they have good similarity with the values obtain during the experiment.
The comparison of the two graphs is that the smooth graph reaches 15mm at 70 0while the roughgraph reaches it in an angle of 600to the rotational. The objective of the experiment wassuccessfully carried out, the comparison of the calculated values are more identical to the valuesobtained during the experiment.