|Introduction||Week 1||Week 2||Week 3||Week 4||Week 5||Week 6||Week 7||Week 8||Week 9||BBL Tasks|
An Introduction to Mechanisms
1 Homework Tasks
1. Cam Profiles
- Name the following cam profiles and explain how it controls the movement of the follower.
2. Pulley Calculations
For each of the problems below - draw a diagram of the pulleys described and then calculate the answer.
- a) A driver pulley has a diameter of 150mm and rotates with a speed of 30rpm. Calculate the speed of a driven pulley with a diameter of 50mm.
- b) A driver pulley has a diameter of 70mm and rotates with a speed of 200rpm. Calculate the speed of a driven pulley with a diameter of 350mm.
- c) A driver pulley has a diameter of 100mm and rotates with a speed of 60rpm. Calculate the required diameter of a driven pulley if we want it to rotate at 150rpm.
- d) We have a driver pulley with a diameter of 80mm. And a driven pulley with a diameter of 40mm. What speed will the driver pulley need if the driven pulley must rotate at a speed of 90rpm?
- e) A driven pulley has a diameter of 10mm and must rotate at a speed of 200rpm. What diameter will the driver pulley need if it can only rotate at 50rpm?
3. DC Motors
Define the following DC motor terms:
- a) Magnetic field
- b) Armature
- c) Commutator
- d) Brushes
Describe the main uses for the following glues:
- a) PVA glue
- b) Epoxy Resin Glue
- c) Super Glue
- d) Spray glues
- e) Clear model glue
5. C.A.D. usage
Answer the following questions:
- a) What is the meaning of the term C.A.D?
- b) How does making a 3D model of a product help a design team develop the product?
- c) Do you thing there is no need to use an expensive piece of equipment such as a laser cutter to make a model? Explain your answer.
6. Mechanism Design
A local florist has asked you to design a model to be placed next to the checkout. The mechanism (shown Below) is nearly complete but a simple mechanism needs adding. The mechanism must make the characters arm move up and down in a fairly smooth movement.
- a) Complete the drawing by adding the mechanism.
- b) Explain how it works?
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