Activity 4.2 Model Creation
Introduction
To effectively use a CAD program to create 3D models of a part, a designer must be
familiar with the basic strategies of additive and subtractive modeling methods. This
activity will help you understand the sketching tools and extrusion features that are
common to most CAD programs, plan an efficient method of simple model creation,
and gain experience creating simple 3D models.
Equipment

Computer with 3D CAD solid modeling program
Procedure
Follow the instructions to create 3D solid models of each of the following objects
using the specified method(s) and respond to the prompts.
1.
All dimensions are in inches.
a.
Create a 3D solid model of the object above using the most efficient method.
b.
Which method (additive, subtractive, or a combination of additive and
subtractive) did you use? Why do you feel it was most efficient?
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Introduction to Engineering Design Activity 4.2 Model Creation Answer Key – Page 1
2.
All dimensions are in mm.
a.
Create a 3D solid model of the object above using the most efficient method
possible.
b.
Describe the method you used to model the object. Why do you feel it was
most efficient?
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Introduction to Engineering Design Activity 4.2 Model Creation Answer Key – Page 2
3.
All dimensions are in inches.
a.
Create a 3D solid model of the object above using only additive procedures.
b.
Create a 3D solid model of the object above using only subtractive
procedures.
c.
Which method (additive, subtractive, or a combination of additive and
subtractive) do you feel would be the most efficient method for creating the
object? Why?
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Introduction to Engineering Design Activity 4.2 Model Creation Answer Key – Page 3
4.
All dimensions are in inches.
a.
Create a 3D solid model of the object above.
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Introduction to Engineering Design Activity 4.2 Model Creation Answer Key – Page 4
Hint: Use geometric constraints to properly constrain the cam sketch profile.
For example, a tangent constraint is required between each arc and the
contiguous straight edges of the profile. Also, to make later assembly easier, it
is advisable to vertically align the center points of the arcs.
b.
Describe the method you used to create the object. Make the main sketch
then extrude that, if there is any thing I need to add or take away I extrude in
the opposite direction
c.
Explain the most efficient procedure using a single extrusion to create this 3D
solid model. Try to extrude something that will create the least mistakes
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Introduction to Engineering Design Activity 4.2 Model Creation Answer Key – Page 5
Conclusion
1. Why is it important to consider efficiency when planning your method of creation
before you begin to model an object in CAD? Because if you use a method or
tool that is inefficient if can take a small sketch take along time
2. How can the information provided in the browser of the CAD software help you
compare the efficiency of two different methods of modeling the same object? By
reading them and checking if that is best way to make a 3-D object
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Introduction to Engineering Design Activity 4.2 Model Creation Answer Key – Page 6