4.1.1 Sketch (ger. "Skizze")

A sketch is a 2D-drawing, that can be used to create a volumetric body by using the functions rotate, translate or sweep.

Using sketches is practical if the body you want to create is hard to construct by using basic geometric bodies like block, cylinder, etc.

A sketch should not be too extensive, but it should create a basis with which you can create the final body by adding features.

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Constraints

Constraints (ger. "Zwangsbedingungen") are necessary geometric relations between the elements of a sketch. E.g. lines can be defined as parallel, perpendicular or collinear to an edge, axis, plane, etc. Constraints are used in combination with measurements to exactly define positions of elements within a sketch.

 

Dimensioning a sketch

You have to dimension a sketch according to given requirements. The required measurements are defined by the geometry of your 3D model.

Hint:

You should only use values, that might be changed during the product-development. Values, which depend on other values, should be defined by constraints. This also applies to angles and lengths, that are not explicitly needed.

Fully Constrained

When working on a sketch, you have to make sure, that the sketch is always fully constrained before finishing/closing it. Fully constrained means that all necessary constraints are defined, which means the layout of the sketch is exactly defined.

You have to eliminate all degrees of freedom by constraining your sketch.

Important:

As far as possible, use constraints instead of dimensioning.