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Mechanical Engineering Home >Info: Useful Links > ProE > polygon

(Contributed by Byron Raymond)

These are general rules to use when making any section in sketcher, made a little more specific for polygons.

1. Use mouse sketch (left button). Make your sketch big. Start with a large lines and angles. Get the number of entities correct, but do not worry too much about size; that will come later. Do make sure that you have a closed section (the start and stop points are at the same point). Try to make the shape as near as you can to the real thing. For example, when creating a hexagon, make opposite sides parallel and close to the same length.
2. Align any sketch entities to existing part geometry. If you always want one segment to be colinear with the edge of a part, use an alignment to make it so.
3. Dimension EVERYTHING! Add a dimension for each line and angle between lines. Don't forget to add dimensions so this feature knows where it is in relation to other features.
4. Regenerate. Pro/E will highlight in red all the dimensions it thinks are extra. It's OK to delete these (within reason).
5. Now, look at the assumptions Pro/E is making. They're shown in the sketch by symbols like || for parallel, an upside down T for perpendicular, // for lines of equal length, etc.
6. Once regeneration is successful, modify the values of each dimension to the value you want. Regenerate, and recheck the assumptions. At this point, there may be "extra" dimensions that Pro/E could assume, but does not, since you explicitly tell it what the dimension value will be. You should delete these.
7. Add relations for any remaining dimensions, such that the shape can be resized by modifying only one dimension.
8. Regular polygons have n sides, all the same length. This is an obvious place for relations. The included angle (in degrees) between each line is (180*(n-2))/n, another obvious place for relations.