Cams

Question 1

Cam

Answer 1

changes the input motion, which is usually rotary motion (a rotating motion), to a reciprocating motion of the follower.

Question 2

Where are cams found mm

Answer 2

They are found in many machines and toys

Question 3

What are the 2 parts of a dam

Answer 3

FOLLOWER and the CAM PROFILE.

Question 4

Explain how cams work using the diffamation

Answer 4

diagram 1= cam is in a vertical position
Diagram 2=slow rotates in an anticlockwise direction.
Diagram 3=as it rotates the follow drops down.
diagram 4 =the follower is in its lowest position.
Diagram 5=com continues to rotate follower rises
diagram 6 = it returns to its original position.

Question 5

One cycle

Answer 5

One rotation/revolution of the cam

Question 6

Dwell

Answer 6

When the cam rotators but the follower does not rise or fall

Question 7

The rise

Answer 7

That part of the cam that causes the follower to rise

Question 8

What do all followers do

Answer 8

they all slide or roll on the edge of the cam.

Question 9

What happens a pear shaped cam

Answer 9

As the handle is turned the model moves backwards and forwards

Question 10

Talk about the motion of a pear shaped cam

Answer 10

The movement is gentle although the faster the handle is turned the faster the movement of the model becomes

Question 11

Name throes of followers

Answer 11

Flat follower
Point/knife follower
Roller follower
Offset follower

Question 12

Describe a flat follower

Answer 12

Large flat surface
Can’t follow precise cam
Cam=rotary motion
Follower=reciprocating motion

Question 13

Point knife follower

Answer 13

Mainly works with heart shaped
Detailed profile
Hard steep tips
Goes into tight curves

Question 14

Roller follower

Answer 14

Small roller
Reduces friction and wear and tear between cam and follower

Question 15

Offset follower

Answer 15

Slant straight bottom

Question 16

Name 4 types of follower

Answer 16

Flat follower
Point knife follower
Roller follower
Offset follower

Question 17

What determines which type of cam profile to use

Answer 17

The way the follower needs to move

Question 18

Pear cam profile

Answer 18

Used in shafts of cars
follower remains motionless for about half of the cycle
Second half rises and falls
Pear shape calms caused the follower to rise rapidly as it comes into contact with the bump part of the cam .
Rise and fall happens with equal speed

Question 19

Eccentric

Answer 19

Circular cam
smooth motion.
used in steam engines and pumps.
This camp profile is a circle.
rotation is offset from the centre of the circle
the calm causes rise and fall in a movement known as the simple harmonic rotation.

Question 20

Heart cam

Answer 20

Heart shaped cams allow the follower to rise and fall with uniform velocity. These can cause the follower to rise at the height which remains constant until the follower reaches the grove where it falls sharply at a uniform rate before rising again. These are used to wind threads or sewing machines. 

Question 21

Drop(snail) cam

Answer 21

-causes the follower to rise slowly then fall sharply into the step
- ensure that the rotation of a snail cam is smooth vertical centre line of the cam must be positioned slightly off centre.
-used in cutting produce when the blade is required to fall sharply.

Question 22

What are 4 types of joints and what is the strongest

Answer 22

Butt joint
Dowel joint
Finger joint
Dove tail joint=strongest