PartDesign project

Here the project plan for the PartDesign as part of the Development roadmap.

Purpose and principles

This is a software development project aimed to implement a Part Design capabilities. Its about implementing some core features into the CAD modules of FreeCAD, Part, PartDesign and Assembly.

The development steps are planed here and tracked in the Issue tracking system to get a well formed change log: Issue tracker

Outcome

Aim of the project is to enable FreeCAD accomplish a design task like the one at the right.

This will be achived by using the Sketcher and the PartDesign to design special part and Part to load standard part as STEP (like the linear bearing). The Assembly puts it all together with constrains.

Also an important outcome is the Feature editing methodology. Which gives the user an intuitive approach to instantiating and editing Features. This is importand for all other Modules and Workbenches to be come, to comply to a consistent user interface!

Sketcher

A parametric sketcher with a geometrical constraints solver, for more details see the Sketcher project.

PartDesign

Body feature

Since a history based modeling can have a lot of steps leading to the final shape a bracket is needed. Thats the Body, which holds the final outcome of the modeling and acts as a group to all the features of the history tree.

Pad feature

A Pad feature extrude a Sketch (or any Part2DObject) in its normal direction. Always guaranty a solid, or fail.

Pocket feature

Imprint a sketch in a base solid either defined by depth or "Up to last | Up to first". Also guaranty a solid.

Bore feature

Very good bore parameter definition from the NaroCad specification:

NaroCAD Bore definitions

Pattern

Replicate one of the above features

RectangularPattern

Replicate one of the above features along an x,y pattern

CircularPattern

Replicate one of the above features along a pattern in polar coordinates

ScriptedPattern

Replicate one of the above features according to a general rule provided in form of a script.

Brainstorming

What others do

• SolidWorks examples

Pattern Implementation

The Pattern feature class can be implemented as a tabular pattern and serve as a base class for the Rectangular, Circular and Scripted Pattern features. These derived classes will only have to fill in the repetitions table of the base class.

Each line of the repetitions table of the base Pattern class has to hold at least a transformation matrix to applied to the Placement of the original feature to be replicated. Additionally we could have optional transformation rules like for example manipulating some parameter value the feature to be replicated (e.g. in order to create a pattern of holes with varying radius).

Organizing

Modeling objects hierarchy

This UML chart shows the planed object hierarchy and its relationships. Yellow is a abstract base class, blue implemented and grey is planed.

Tutorials

PartDesign Bearingholder Tutorial I

PartDesign Bearingholder Tutorial II

Next actions

Next actions are defined in the Roadmap entry for PartDesign:

Body

Since the parametric/associative nature of the PartDesign we need finally a "Body" which groups and organizes a construction history. The Body itself holds the end result as a shape and has grouped as children the PartDesign features. It also defines the actual head of the modeling history. Its also related to the Assembly project since its the building block for products and compounds.

Additional features

The Pad and Pocket features are the first teaser for the PartDesign. There is still work to do especially the visibility control and the visual manipulators. But then additional features are needed.

Pattern

Pattern feature which repeatingly apply a Pad or Pocket feature according to a circular or rectangular patter. An Example in IronCAD. Done [jrheinlaender]

BoreHole

Classical bore hole with all parameters for threading and counter bore....

Sweep

Sweeps a Sketch along a curve and create a Solid.

Revolve

Rotate a Sketch along one of its Axis and a certain angle. Done [jrheinlaender et al.]

TODO List

1. Fillet/Chamfer Part
   1. Apply fillet/chamfer operation to different selection types (face/faces pair/whole body)*
2. Pad Tool
   1. Create 'up to next' mode DONE [mrlukeparry]
   2. Create 'up to surface/face' mode [mrlukeparry]
   3. Create draft property for pad DONE [mrlukeparry]
   4. If pad is selected on face automatically create a sketch?
   5. Create 'midplane' mode DONE [jrheinlaender]
3. Pocket Tool
   1. Create 'up to first', 'up to last', 'through all', 'up to surface/face' modes DONE [jrheinlaender]
   2. If pocket is selected on face automatically create a sketch?
4. Revolution Part
   1. Allow a generic line segment/axis to be used for reference
   2. Create 'midplane' mode DONE [jrheinlaender]
5. Hole Feature
6. Pattern Feature DONE [jrheinlaender]
7. Sweep Feature
8. Body Feature
9. Reference Geometry
   1. Plane
10. Mirror Tool DONE [jrheinlaender]
11. Copy feature Tool