Prototyping in Design - UBC Engineering APSC 100/101 Week 9

Week 9 Class B: Prototyping in Design

• Course: UBC Engineering APSC 100/101 (M3-W9-A)

Learning Goals

• By the end of this section, students should be able to:

  • Describe the use of computing tools in the engineering design process.

  • Describe the use, benefits, and limitations of CAD as a prototyping tool.

  • Evaluate the use and purpose of various example prototypes in engineering design.

  • Outline the key deliverables and requirements for Module 3.

Content Reference

• Previous Modules:

  • Definitions and a classification system for prototypes (Module 1).

  • Experience using CAD (two exercises).

  • Design brief and Module 3 stakeholder screencast.

Class Additions

• Assessing CAD as a prototyping tool, focusing on its uses and limitations.

• Critically evaluating the choice of prototypes in the development of different products.

• Supporting students in advancing their Module 3 project planning.

Prototypes Classification and Use

• Classification types:

  • Focused

  • Comprehensive

  • Physical

  • Simple

  • Inexpensive

  • Quick

  • Complex

  • Expensive

  • Time-consuming

• Example Prototypes and their Classes:

  • CAD models

  • Sketches

  • Proofs-of-concept

  • Beta prototypes

  • Simple mock-ups

  • Rapid prototypes

Functions of Prototypes

• Purpose of prototypes to:

  • Determine placement and orientation.

  • Understand ergonomics and workflow.

  • Communicate form and shape.

  • Inspire new ideas.

  • Enter the initial market.

  • Visualize and communicate ideas.

  • Demonstrate final function and form.

  • Address specific project risks.

Computing Tools in the Engineering Design Process

• Utilized tools include:

  • Computer-aided design (CAD)

  • Visualization / virtual reality tools

  • Simulation and mathematical models

  • Project management and collaboration software

  • Digital manufacturing tools

• Example: A model created in SolidWorks and rendered in Gemini.

Computer-Aided Design (CAD)

• Definition: "Describes a process in which a software package is used to create a detailed two- or three-dimensional representation of a physical structure."

Key Benefits and Challenges of CAD

• Benefits:

  • Enables creation of detailed production drawings.

  • Facilitates the development of precise computer simulations.

• Challenges:

  • Does not encourage divergent thinking necessary in early concept stages.

  • Can lead to fixation as it requires commitment to the design.

  • Slower compared to sketching or tinkering.

• Optimal Use: Best suited for Stage 4 (development and testing).

Module 3 Planning and Activities

• Appropriate Use of GenAI Tools:

  • Review and critique design concepts.

  • Research user needs and evaluation criteria.

  • Estimate quantities (e.g., time and cost for 3D printing).

  • Generate production quality images from CAD files.

Activity Example

• Generate a publication-ready image of your keychain CAD file using various tools (e.g., Microsoft Copilot, ChatGPT, Google Gemini).

  • Task: Develop a photorealistic image incorporating joyful elements, ensuring consistency and natural lighting while adhering to constraints.

Check-in and Timeline

• Week 9:

  • Select project and identify needs.

  • Begin concept generation.

• Upcoming Weeks:

  • Week 10: Module 2 Oral Presentations.

  • Week 11: Reading Break, develop designs and CAD models.

  • Week 12: Evaluate and select a concept.

  • Week 13: Prepare promo sheets and technical memos.

Module Deliverables

• Technical Memo:

  • Audience: Senior engineers selecting ideas for production.

  • Purpose: Recommend a solution and justify it.

  • Context: Internal document with approximately 180 proposals.

• Promotional Sheet:

  • Audience: Investors reviewing promising projects.

  • Purpose: Inform and persuade about your design idea.

  • Context: Used alongside a short pitch.

Homework Assignments

• Team Homework (Due Monday, 8 am):

  • Submit your list of needs and draft target design specifications.

• Individual Homework (Due at start of Week 12):

  • CAD design files and photos of your solution.

Week 10 Class A: Stress, Strength, and Use of Material

• Learning Goals:

  • Describe how shape and load orientation affect stress in rods and beams.

  • Identify guidelines for shape and geometry to minimize stress and deflection in the Module 3 project.

Project Relevance

• Assessment of device capabilities:

  • Supporting applied forces efficiently.

  • Evaluating potential deflection and efficiency in material use to keep costs and weight down.

Instructions for Class Activities

• Conduct a series of mini-experiments to explore the behavior of sticks under various forces and conditions, gathering observations to link insights back to concepts covered in previous modules.

Specific Experiment Guidelines

• Case A: Test elasticity in tension versus compression and cantilever beam conditions.

• Case B: Investigate deformation under varying dimensions while noting critical failures.

Useful Relationships in Stress Analysis

1. Tensile stress may lead to failure if:

   • ext{σ} > ext{σ}_{ut} (Ultimate tensile strength)

   • ext{σ} > ext{σ}_{y} (Yield strength)

2. Maximum bending stress in a rectangular cantilever beam:

   • $ext{σ}_{max} = rac{6F L}{b h^2}$

   • For a cylindrical beam of diameter $d$:

   • $ext{σ}_{max} = rac{32F}{ ext{π} d^3}$

Shape Efficiency and Structural Considerations

• Comparative Analysis of Beams:

  • All beams can have the same volume and force applied, yet exhibit different peak stress levels based on their geometries.

Cap Remover Case Study

• Analysis of three designs for a cap remover to determine which design requires the lowest force to open a bottle and which will yield first under torque stress.

• Each design variation will utilize the same volume of material, providing a basis for evaluating efficiency based upon shape and material distribution.

Week 11 Class B: Rapid Prototyping and Material Use

• Learning Goals:

  • Summarize principles, benefits, and limitations of rapid prototyping methods: 3D printing, waterjet cutting, and laser cutting.

  • Assess the appropriate manufacturing techniques for producing parts based on design criteria.

  • Analyze structural designs concerning loads, stresses, and material efficiency.

Activity Examples in Manufacturing Methods

• Fused Deposition Modeling (FDM):

  • Fast and cost-effective for prototypes with moderate complexity.

• Selective Laser Sintering (SLS):

  • Ideal for functional parts with complex geometries.

• Waterjet Cutting:

  • Less thermal distortion; applicable for a variety of materials.

• Team Activity: Redesign a sample product to be compatible with rapid prototyping methods while ensuring its functional integrity is maintained.

Elevator Pitch Preparation

• Learning Goals:

  • Identify components of an elevator pitch.

  • Develop a compelling pitch to convey design concepts.

• Applications of elevator pitches in finding funding and presenting ideas clearly and effectively to potential investors.

Ethical Dilemmas in Engineering

• Learning Goals:

  • Identify self-regulation risks and advantages.

  • Explore the ethical framework guiding decisions in engineering contexts.

• Discussion Scenarios:

  • Self-regulation in workplace examples, especially concerning pressure to approve work without proper qualifications, and how ethical theories suggest approaches for resolving conflicts.

Key Ethical Theories Explained

1. Utilitarianism: Promotes actions that maximize overall happiness/moral benefit.

2. Duty-Based Ethics: Adheres to principles of honesty and fairness regardless of outcomes.

3. Rights-Based Ethics: Focuses on respecting individuals’ rights and freedoms.

Conclusion

• Emphasizes the importance of effective communication, self-regulation, and ethical considerations in engineering practice and reinforces the critical integration of technical skills with ethical decision-making in today’s complex environment.