MACHINE: A combination of mechanical devices which together apply forces and control movement to perform an intended action.
FUNCTION: The purpose of a machine/mechanical device. (Machines can have more than one purpose)
DESIGN: How a device appears (aka its ‘form’). The design should suit the function.
Machines and mechanical devices have evolved over time because of science and the development of new technologies. The design and function of a machine is related to its efficiency and effectiveness.
Look at the wheels above, has their design evolved? How is their design better? How do we evaluate a better design?
Q: So how do people (engineers/designers) know which mechanical device is the best? A: They use a set of criteria to evaluate and analyze the mechanical device. (AKA we need a system to keep score!) Criteria need to be specific to properly evaluate a machine/mechanical device:
Design
Is there a better design to complete it’s function?
Effectiveness
Does it fulfill it’s function well without breaking for prolonged periods? (ex. gas powered mower vs. push mower)
Efficiency
Is it performing work efficiently? (ex. using a push mower takes longer to mow the lawn)
Price
Is it expensive to build?
Is it easy to manufacture, can it be manufactured quickly?
Unwanted costs
Does it create wastes? (ex. Gas powered lawnmower has more parts than a push mower)
Can we make it less harmful for the living environment ? (ex. Gas powered lawnmower releases greenhouse gases)
Aesthetics
Does it look pleasing to the eye, does it need to look pleasing?
Environment
Perhaps the device works great only in certain environments? (ex. BMX bike for Tour de France)
Is it being used safely? (ex. single speed bike in a BMX course)
Ergonomics
How well do humans interact with the device?
EVALUATE THE FOLLOWING MECHANICAL DEVICE:
Evaluate different versions of a mechanical device using the criteria given. (ex, vehicle from 1900, 1950, 2000)
CSA: A non-government association that tests and approves a wide range of products to ensure they are safe for use by the consumer. CSA stands for Canadian Standards Association.
TECHNOLOGICAL ADVANCES AND MECHANICAL DEVICES
Technology and devices have come a long way since the invention of simple machines. Advances in technology can have broad implications on human society:
Changes in society
Changes in the environment
Changes in production capacity
Changes in human behaviour
Watch the following video and write down all the different changes in society, human behaviour, environment, and production capacity.
EVALUATION OF MECHANICAL DEVICES ASSIGNMENT
Research a mechanical device/machine that you would like to evaluate. The mechanical device/machine should include simple machines and be commonly used (ex. can opener)
Summarize the specific function of the device/machine
The evaluation submitted should use the following eight evaluation criteria to draw an analysis of the mechanical device/machine. Each evaluation criteria should have at least two bullet points discussing the criteria (one pro, one con)
HINT: If you can not think of a mechanical device/machine you would like to evaluate, then evaluate a gas powered Lawn Mower — evaluate how its design is an improvement in contrast to the classic Push Mower. 4. Below you will find the evaluation criteria to be used along with the format of how to evaluate the mechanical device. Please submit using the format shown below.