4.4.2 Sketching efficiently

This exercise deals with fast and efficient creation of sketches.

To sketch efficiently, you should always follow the rule of creating sketches as simple as possible. Models should consist of different features and not be derived from one complex sketch.

Associative correct sketches are equal to detail-features. The complexity should have an adequate relation to your modeling goal. Under some circumstances it makes more sense to replace complex sketches with features.

Attention:

As a rule of thumb you should create sketches with max. 6 line elements. It's also advised to observe any hint given during the exam phases.

Sketch an "E" in sketch mode

The goal of this exercise is not to sketch an "E" from one closed line (refer figure "Extruded bodies"), but to use, as far as possible, basic features like rectangles.

Complete the following steps:

Create a new model e_sketch according to the naming convention.
Sketch a rectangle in sketch mode (confirm default drawing plane) and position it in the point of origin. Normally you would create geometry like that with the feature Block. We won't do that here for better overview regarding the orientation of the sketch.

This rectangle should have the following dimensions:

Dimension	Value [mm]
Height	30
Width	20

- End sketch mode.
- Extrude the rectangle along the Z-axis for -15mm.
- Open sketch mode and confirm the drawing plane.
- Create a rectangle and position it as shown in the picture on the right. (refer figure "Positioning")
- End sketch mode.
- Subtract the rectangle with along the Z-axis for -15 mm (Boolean function Subtract ). It could be helpful to switch display to Wireframe with dim Edges beforehand, to clearly see any relevant edges.
- Now you should get this u-shape. (refer figure "Positioning bar")
- Open sketch mode again.
- Place another rectangle in the u-shape to create the middle bar of the "E".
- Position it as shown in the picture on the right.
- End sektch mode and extrude the rectangle along the Z-axis for -15mm (Boolean function Unite ). (refer figure "Extruded bodies")

In this exercise you learned that it is not practical to compose a sketch of many connected lines. That means more sketches are necessary to create the geometry, but the model can be edited easily later on.

This is a significant advantage for complex models. If you need to change specific dimensions later on, editing simple, overviewable sketches are easier.