HOMEWORK: I-DEAS

The objectives of this assignment is simply to show you a few aspects of how geometries are modeled in a typical CAD interface. You are expected to do problem 1 with good dimensional accuracy by defining the points as coordinates; the dimensions for Problems 2 and 3 are up to you.

In this homework, you are required to model the three objects shown using the methods suggested.

1. EXTRUSION / SYMMETRY: Gear tooth. Build this up by defining the curved contour and extruding it. Then reflect it about the yz plane to create the gear. This is one of the most common methods used for defining geometries. Define this section by joining the following points:

0    0	     (center of gear)
0    27      (start of spline)
0.76 27		
1.8  25.3
2.6  23.7
2.9  22.5
2.92 21.55
2.68 19.82   (end of spline)
4.16 19.56

An inner radius of 15, centered at 0,0 is to be removed from this section.

The segment from (0.76 27) to i(2.68,19.82) is a simple spline. The rest are all straight lines. There is a fillet of 1mm at point 8 (2.68,19.82).

Once you have this section, remove the inner radius of 15, which will leave the basic section. Reflect this to get the whole tooth. Extrude! Voila!

2. LOFTING: Define four equally spaced square shapes as sections for a lofting operation. Loft between them, specifying a rotation of 90 degrees between each section.

3. SWEEPING: Define a rectangle section. Define a vertical axis. Sweep the rectangle section about the vertical axis with

Translation along the axis by a sufficiently long distance and
Rotation by a large angle (e.g. 3600 degrees = 10 turns).

Experiment with other sections and shapes.

REMEMBER: You will need to show your work to Praveen Tayal, who will record that it is completed.