Figure 1 – The concept of degrees of freedom and corresponding terms.

Our objective is to eliminate degrees of freedom. For the time being, think

of degrees of freedom in terms of Murphy’s law, e.g., as things that can go wrong.









Figure 2A complete multiview drawing specifies everything required to

create the part to a given standard of quality. Besides the six basic degrees of freedom illustrated in Figure 1, there are a multitude of additional

“manufacturing” degrees of freedom we must remove. The science of

eliminating these manufacturing degrees of freedom is communicated in the

language of dimensioning and tolerancing.




Figure 3 As a small initial step, we start by defining DATUMS.


EXERCISE 4-1: Reproduce the models on P.159 13-21 and create working drawings of them

with Datums and Dimensions. (Use the graphs to determine ratios)(Also, use

primitives as much as possible to create the shapes.)

You will assign the 3 Datums, Primary-Secondary & Teritary, to appropriate surfaces of each model, and assign geomentric relationships using

Feature Control Frames. Save all files in the Q: and Print out each working drawing.


You will need the little reference book for Geometric Tolerances



Exercise 4-2: Create a presentation view of your Composite Model of last week. Save it as a .jpg and place it on a 22 x 34 layout in PowerPoint.

Save all work on the Q: Drive.