## Design of Mechanical Assemblies413 student Resources

### Guide to Mini-Projects

#### Prose

• Restatement of the problem, what was provided and explanation of how initial variables were calculated (ex. Torques)
• Explicit statement of your objectives- what are you optimizing? Why did you chose to optimize this?
• Clear identification of the system degrees of freedom
• Clear identification of system constraints
• Any assumptions made should be stated. Design decisions that are not analytical such as material choice should be explained here.
• Explanation of design method must be clearly explained
• All parameters and how their values were determined should be explained. Phrases such as "x was minimized because...", "y was set equal to z because..." should be used with a comment on how doing so helped to achieve your objectives
• Comments on the final design should be included. What are the strengths? What are the weaknesses?
• If applicable comments on how the design is assembled, mounted, connected to other assemblies etc. should be explained
• Should be clear and concise

#### Approaching the problem

1. Understand the scope of the project: What you are being asked to design? What are you trying to accomplish? What initial calculations are required?
2. Using the provided information calculate any initial values that are inputs to the system. How does the provided information relate to the design?
3. Based on the application of the design determine what should be optimized. What are the possible variables that could be optimized? Cost, Weight, Size, Lifetime? How did you determine which are your main objectives? State clearly justification and reasoning supporting your choice.
4. Based on the provided information determine what values are constant and which values are design parameters. Create a list of the Degrees of Freedom for the system. Create a list of the systems constraints.
5. Gain a clear understanding of what effects each degree of freedom has on what you are optimizing. If everything else was held constant and does increasing or decreasing your parameter value help you better achieve your objectives?
6. Determine any parameter bounds. What are the minimum and maximum values that the variable can be assigned? Establish limits if there are any. These bounds can either be determined by equations or physical constraints/conditions.
7. Establish the interdependence of degrees of freedom. If x is increased what happens to y? what combination of x and y values help achieve your objectives? Graphs in this part of design are often required when relationships aren't trivial. Important relationships between degrees of freedom should be clearly stated.
8. Using discoveries from steps 5-7 establish a clear method/path of design. Each parameter value should have an explicit value assigned to it with reasoning or a method behind how it was determined. Iterating might be required and is an acceptable step that can be integrated into your method.
9. Create visualization of the assembly based on the determined parameter values. Do other variables need to be considered? Think outside of the design variables- how is everything going to be attached? Will the system run smoothly, does it make physical sense?
10. If applicable: How does the design fit into the larger system? How will it be mounted? Explain how it will interact with other system components if it applies to the problem.

### Visual References

#### Gears

Skip to 34 seconds in the video below to see what undercutting looks like in motion. Undercutting causes interference effecting the movement of the gears which is demonstrated.

#### Brakes

Caliper Brake- depicts how brake fluid is used to activate a piston

multi-disk clutches- An example of how multi-disk clutches engage and disengage

Solenoids- Shows when they contract and when they are extended

# Report Abuse

If you feel that this video content violates the Adobe Terms of Use, you may report this content by filling out this quick form.