FreeCAD Help - Granet JP - Limoges - France

Classic construction principle with the PartDesign WB

You must start with a block of material ...

To start from a block of material, you can :

create material yourself from an additive primitive form :

create material yourself from an add material feature that relies on sketches. It is this mode of creation that will be developed here.

Main classic features : (hover over images)

pad

revolve

loft

sweep

More informations

import material from a solid external to the body, called BaseFeature
(not covered in these pages).

This additive primitive shape will then be dimensioned and positioned in the local frame of reference of the body by modifying its properties.

Example :

Default dimensions and position :	Modified dimensions and position :

Classic material addition features

Depending on the functionality chosen, you will need one or more sketch(es).

Each sketch must be built in a plane chosen beforehand among the 3 standard planes of the body, or specially created and positioned from these (datum or reference plane).

Each sketch outline will then be sized and positioned in the local coordinate system of the sketch plane chosen as the support.

We say that the sketch is "attached" to its support plane. If the support plane is moved, the sketch "follows" it.

It is also possible to designate a plane face of the existing material as a support for a new sketch, but for unresolved problems of "topological naming", this is still not recommended in the case of complex models which must be able to be modified or adapted in a more or less near future.

Sketches

The construction of a plane contour which will serve as a support for the function of creation or removal of material is called a sketch.

A sketch is required for typical add or remove functions; for some functions you even need several (sweeping, smoothing).

A sketch should be closed (most often), without overlapping entities, without intersections.

A sketch can contain multiple closed contours, as long as they have nothing in common.

These contours must be in strong continuous lines. The "construction" lines (in blue in FreeCad) can be used for the positioning of entities but will not be taken into account by the creation functions.

Examples :