Activity 1.3.4: Linear Dimensions

Introduction

If you were given the responsibility of going to a store and purchasing a throw rug that had to fit within a room in your home, how would you communicate the shape and size of the room to the salesperson?

Given the sketching skills that you’ve developed, you would probably sketch a top view of the room on a piece of paper. This would be useful, but a sketch alone only communicates shape information.

A shape has various sizes that must be communicated in order to make intelligent design decisions. Information about an object’s size must be dimensioned fully so that if given to a manufacturer the object or part could be created. If a part is not dimensioned correctly, and the manufacturer creates the part incorrectly, the problem would be the designer’s and the process would have to start over. This could be costly if mass producing and profits plummet.

Equipment

·  Number 2 pencil with eraser

·  Engineer’s notebook

·  Inch scale or ruler

Procedure

In this activity, you will apply your knowledge of dimensioning to identify missing dimensions on multiview drawings. You will also fully dimension multiview sketches and properly order and locate those on the problems below.

Dimension the following sketch. Each square on the grid equals .25 units.

Dimension the following sketch. Each square on the grid equals .25 unit.

Fully dimension the following sketch. Each square on the grid equals one unit. The unit is in inches.

Extending Your Learning

This problem has students dimension an angle.

Fully dimension the following sketch. Each square on the grid equals one unit. The unit is in inches.

Optional: Go back to the last five multiview sketches that you made in Activity1.2.4. Fully dimension each multiview sketch. Each square on the grid equals one unit. The unit is in inches.

Conclusion

1.  Why is placement of your dimensions so important?

2.  What is the difference between size dimensions and location dimensions?

3.  Why do designers need to fully dimension a part?

4.  What does it mean when a sketch is over dimensioned?

Project Lead The Way, Inc.

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IED – Unit 1 – Lesson 1.3 – Activity 1.3.4 – Linear Dimensions – Page 4