Design and Modeling

Measurement

Sketching and Dimensioning

Designing for Production

Concepts

1. In the United States, we use both Standard and Metric systems of measurement.
2. Being able to measure accurately is important at school and at home, at work and when pursuing hobbies.
3. Precision measuring tools are needed for accuracy, but tools must be used correctly to ensure accurate measurements are taken.
4. Quality workmanship and accurate measurements with precise instruments are necessary to successfully solve problems.

Performance objectives

It is expected that students will:

• Select the appropriate value from a conversion chart to convert between standard and metric units.
• Convert between standard and metric measurements including inches, feet, yards, millimeters, centimeters, and meters.
• Demonstrate the ability to measure accurately with different devices and scales using both the standard and metric systems.
• Explain how to measure in different contexts.

Essential Questions

1. Do you think the U.S. should convert to all metric measuring, or should the U.S. stay with using both the Standard and Metric systems? Why?
2. Why don’t we use such measurement forms as the hand span, cubit, and pace very often today?
3. Give two reasons why precision measuring tools are not always accurate.

Concepts

1. The ability to create a rapid, accurate sketch is an important skill to communicate ideas.
2. Orthographic drawings of an object are used to provide information that a perspective drawing may not be able to show.
3. Engineers apply dimensions to drawings to communicate size information.

Performance Objectives

It is expected that students will:

• Summarize the reasoning for using sketching as a communication tool.
• Use visualization, spatial reasoning, and geometric shapes to sketch two and three dimensional shapes.
• Recognize thumbnail, perspective, isometric, and orthographic sketches.
• Recognize one and two point perspective drawings.
• Create thumbnail, perspective, isometric, and orthographic sketches.
• Accurately interpret one and two point perspective drawings.
• Communicate ideas for a design using various sketching methods, notes, and drafting views.
• Dimension an orthographic sketch following the guidelines of dimensioning.

Essential Questions

1. What are pictorial drawings and how are they used by engineers?
2. What is an orthographic drawing and how is it used by engineers?
3. Why is it important to follow the “rules” of sketching and dimensioning?

Concepts

1. Simple geometric shapes are combined and joined to create a representation of an object.
2. Engineers use computer-aided design (CAD) modeling systems to quickly generate and annotate working drawings.
3. Three-dimensional computer modeling uses descriptive geometry, geometric relationships, and dimensions to communicate an idea or solution to a technological problem.
4. As individual objects are assembled together, their degrees of freedom are systematically removed.
5. Engineers use a design process to create solutions to existing problems.
6. Teamwork requires constant communication to achieve the goal at hand.
7. The fabrication of a prototype is the opportunity for the designer to see the product as a three-dimensional object.

Performance Objectives

It is expected that students will:

• Describe the coordinate system and how geometric shapes work together to create objects.
• Create a three-dimensional (3D) model of an object.
• Apply geometric and dimension constraints to design CAD-modeled parts.
• Assemble the product using the CAD modeling program.
• Demonstrate the ability to produce various annotated working drawings of a 3D model.
• Identify the difference between a prototype, a model and a mock-up.
• Analyze what circumstances call for the use of a prototype, a model, and a mock-up.
• Describe why teams of people are used to solve problems.
• Brainstorm and sketch possible solutions to an existing design problem.
• Create a decision-making matrix.
• Use a decision making matrix to select an approach that meets or satisfies the constraints given in a design brief.

Essential Questions

1. Why would engineers use three-dimensional (3D) modeling when solving technological problems?
2. How do assembly constraints differ from geometric and numeric constraints?
3. What is the difference between a hand-drawn sketch, a working drawing, and a 3D model?
4. What is the difference between a part file (.ipt), an assembly file (.iam), and a working drawing (.idw)?
5. What is the difference between a model, a mockup and a prototype?
6. What purpose do annotations serve in an assembly drawing?
7. Why is it important to follow the design process when creating a solution to a problem?
8. Why are teams of people used to solve problems?