Part Modeling > Engineering Features > Draft > About the Draft Feature
About the Draft Feature
The Draft feature adds a draft angle from -89.9° to +89.9° to individual surfaces or to a series of surfaces. You can draft only the surfaces that are formed by tabulated cylinders or planes. To access the Draft feature, click Model > Draft.
You can draft either solid surfaces or quilt surfaces, but not a combination of both. When you select surfaces to be drafted, the first selected surface determines the type of additional surfaces, solid or quilt, that can be selected for this feature.
For drafts, the system uses the following terminology:
Draft surfaces—The surfaces of the model that are being drafted.
Draft hinges—Lines or curves on the draft surfaces that the surfaces are pivoted about (also called neutral curves). Draft hinges can be defined by selecting a plane or quilt, in which case the draft surfaces are pivoted about their intersection with this plane, or by selecting individual curve chains on the draft surfaces.
Pull direction (also called draft direction)—Direction that is used to measure the draft angle. This is usually the direction of mold opening. You can define it by selecting a plane (in which case the pull direction is normal to this plane), a straight edge, a datum axis, or an axis of a coordinate system.
Draft angle—The angle between the pull direction and the resulting drafted surfaces. If the draft surfaces are split, you can define two independent angles for each side of the drafted surface. Draft angles must be within the range of -89.9° to +89.9°.
Draft surfaces can be split either by the draft hinge or by a different curve on the draft surface, such as an intersection with a quilt, or a sketched curve. If you are splitting by a sketch, the system extrudes it to a quilt within the draft feature, in the direction normal to the sketching plane. If the draft surfaces are split, you can:
Specify two independent draft angles for each side of the drafted surface.
Specify a single draft angle, with the second side drafted in the opposite direction.
Draft only one side of the surface (either one), with the other side remaining in the neutral position.
When the surfaces to be drafted include rounds, you can either preserve the rounds, and they remain rounds, or you can draft the rounds, and then they become conic.
If you propagate a draft, the system expands the selection of surfaces to be drafted. The draft adds surfaces until a sharp edge or a surface that cannot be drafted is reached. The draft_tan_propagation_default configuration option defines the default of whether to propagate a draft or not. The command defines whether to propagate a draft for the draft feature.