AUTOMATION ELEMENTS MACHINE IN DESIGN

IAT 0932

Introduction

A cam and follower system is system or mechanism that uses a cam and follower to create a specific motion.  The cam is in most cases merely a flat piece of metal that has had an unusual shape or profile machined onto it.  This cam is attached to a shaft which enable it to be turned by applying a turning action to the shaft.  As the cam rotates it is the profile or shape of the cam that causes the follower to move in a particular way.  The movement of the follower is then transmitted to another mechanism or another part of the mechanism.

Due to the profile of the cam, the rate of the follower move up and down can be controlled. When the cam turn through one motion cycle, the follower executes a series of events consisting of rises, dwell and return. Rise is the motion of the follower away from the cam center, dwell is motion during which the follower is at rest, and return is the motion of the follower toward the cam center. The cam performance can be determined by horizontal position of the cam and follower system. The period of time, T of the follower movement (up and down) and rotation angle of cam, can be measured and analyzed.

The variety of different types of cam and follower systems that one can choose from is quite broad. e.g.

Plate Cam with Knife-edge follower Roller follower Flat follower

Clyindrical Cam with roller follower

Procedure

1) The convex cam is placed on the cam shaft holder and cup follower is attached at the end of rod. The cam and follower tighten through screw.

2) The circular protractor is set to the desired position (pointer at zero), meanwhile the weight and dial gauge were set in position.

3) Cam is rotated by hand and the dial gauge readings are noted down for every 5 interval of rotation.

4) The displacement diagram is plotted on a graph paper with desired scale against the cam angle.

5) Convex cam and cup follower are removed, and then step 1 to 4 is repeated by using tangent cam with roller follower and concave came with roller follower.

6) Concave cam removed, and then step 1 to 4 is repeated by using unsymmetrical cam with a rocker arm. Rocker arm is placed on the support of rocker arm on the Cam Mechanism.

Tools

Figure 1 : Set of tools

Figure 2: Unsymmetrical Cam Figure 3: Convex Cam

Figure 4: Tangent Cam Figure 5: Concave Cam

Figure 6:Cam Mechanisms Figure 7: Rocker Arm

Figure 8: Cup Follower Figure 9 : Roller Follower

Result

Angle

Convex Cam With Cup Follower

Tangent Cam With Roller Follower

Concave Cam With Roller Follower

Unsymmetrical Cam With Rocker Arm

Stroke Stroke Stroke Stroke80 0 0 0 075 0 0 0 070 0.01 0 0 065 0.32 0.15 0.22 0.1860 0.86 0.54 1.22 0.7055 0.85 1.48 3.6 1.6550 3.19 2.36 6.92 2.945 5.1 4.87 8.52 4.4840 6.9 6.76 10.59 6.4635 8.8 8.28 12.34 8.3530 10.4 10.66 13.64 10.125 11.81 11.92 14.52 11.4220 13 12.33 15.95 12.6515 13.89 14.48 15.04 13.6310 14.55 15.86 15.04 14.325 14.92 15.86 15.07 14.690 15.4 15 15.06 14.915 14.86 14.86 15.05 14.7910 14.46 14.47 15.06 14.4015 13.75 13.74 15.07 13.7920 13.84 12.73 15.08 12.9025 11.33 11.47 14.83 11.7030 10.13 9.97 14.15 10.4035 8.44 8.20 13.05 8.7540 6.57 6.21 11.14 6.9245 4.61 5.26 9.15 4.9450 3.97 2.60 6.63 3.2755 1.61 1.28 4.78 1.8860 0.78 0.66 1.55 0.9065 0.19 0.20 0.49 0.2970 0.65 0.40 0.18 0.0675 0.6 0.40 0.18 0.0380 0.7 0.40 0.18 0.03

Graph

80 70 60 50 40 30 20 10 0 10 20 30 40 50 60 70 800

2

4

6

8

10

12

14

16

18

Series 1

Series 1

Figure 1 : Convex Cam

80 70 60 50 40 30 20 10 0 10 20 30 40 50 60 70 800

2

4

6

8

10

12

14

16

18

Series 2

Series 2

Figure 2 : Concave Cam

80 70 60 50 40 30 20 10 0 10 20 30 40 50 60 70 800

2

4

6

8

10

12

14

16

18

Series 3

Series 3

Figure 3 : Concave Cam

80 70 60 50 40 30 20 10 0 10 20 30 40 50 60 70 800

2

4

6

8

10

12

14

16

Series 4

Series 4

Figure 4 : Unsymmetrical Cam

Discussion

When conducting this practical, we experience some of problem that lead to the error and caused our result inaccurate and inprecise. Among the problem are:

1) Parallax error which occur when we observe and read the instrument result on the scale of the meter. Our observer eye is not precisely perpendicular to the plane of the scale. This cause set apart from the actual reading.

2) Gauge Pointer is not accurately locate at zero level. This problem lead us to zero error problem.

Finally, from what we observe from the practical, we can learn about the type of the cam used in industry. We also able to learn about the uses of the followers according to the cam design and type. From the graph that we obtained we can know that the concave cam have big differences stroke from the other cam because in zero degrees of this cam doesn’t reach the high value like other cam that we used in the practical. The other cam doesn’t have a lot of differences in terms of stroke because of they design is quite similar to each other.

Conclusion

After conducting this practical, we conclude that we find out that various type of cam that widely use in our daily life and in the industry which is divided into four major part and design that is

1. convex cam,2. tangent cam,3. cancave cam,4. unsymmetrical cam.

From the graph we obtained we also get to know the differences in design between the cam and we use of different type of follower that is cup follower, roller follower, rocker arm to match the cam usage and applications. Last but not least, We successfully achieve our target to know the applications and benefits of uses of the cam in daily life.