At the concept design stage, many people find hand-sketching the quickest way to illustrate and communicate ideas. Once a particular concept has been shortlisted for embodiment, a scale-sketch can be produced as in Figure 17.11. Most of the information can be captured in a side elevation and plan view as shown. However, to be rigorous, a front elevation is also required. For example, the two sketches shown fail to unambiguously capture the geometry of the main undercarriage legs.
If an AirCONICS model is not going to be used to seed the detail design process, such hand sketches can be used to start to create the CAD geometry and therefore need to be reasonably accurate scale sketches with a dimensioned feature in each sketch. Because we are going to later create parametric variables, these do not to need to be exact. These sketches can be imported into a CAD tool to provide an initial starting point for generating exact parametric geometry. The two hand sketches have been positioned orthogonally in Solidworks and scaled appropriately as shown in Figure 17.12. Each sketch has been made partially transparent to allow emerging geometry to be visible through the sketch.