FreeCAD (http://www.freecadweb.org ) is an open-source 3D modeling tool geared toward designing solid objects for mechanical constructions. FreeCAD adopts the workflow where a 3D object is modeled by iteratively extruding or carving (padding or pocketing in FreeCAD terms) from 2D surfaces into the third dimension. The profiles used for extruding or carving are called sketches. Most importantly, FreeCAD keeps a history of your work steps and the parameters. You can modify the parameters that you used for a certain operation in a past work step and immediately see the effects of the change in your current work step! You also don't deal with meshes directly, like you do in Blender. The parameters of your geometric shapes (e.g., radius of a circle) are preserved as such. The conversion to polygons for real-time rendering is managed for you.
Up-to-date Ubuntu packages are available at https://launchpad.net/~freecad-maintainers/+archive/ubuntu/freecad-stable
Video tutorial series by Bram de Vries, based on FreeCAD version 0.14(?)
Notes On Usage
Here are some notes on using FreeCAD. They are based on version 0.16, which was released in February 2016.
- Reordering objects in the object tree is not really possible because it is also tied to the order in which operations were performed (the history). However, you can use the fact that elements are placed at the end of the list when dragged in or out of a group.
- Key combination for toggling the grid: G + R
- Key combination for moving selected part: M + V in Draft workbench.
- Key combination for rotating selected part: R + O (that's an oh, not zero) in Draft workbench.
- Use spacebar to toggle the visibility of parts that are selected in the tree.
- Make use of the tangent constraint when connecting an arc to a line in a sketch, if applicable.
- Use the Fillet Edges tool to round corners in the Part Design workbench.
- Use the button to create an edge linked to an external geometry in order to use an existing edge in your sketch.
- Use the constraint put point on line constraint to require that the selected point must lie on the selected line.
- There is currently no way to link to a part in another FreeCAD file like you can do in Blender. That is, importing a part from another file without making a local copy and automatically getting all subsequent changes made to the original part. The Assembly workbench will enable this but is still under development. There is an alternative solution available as a macro.
- In a sketch you can use the Construction Mode button to mark helper lines that are used only for fixing the sketch geometry and should be excluded from the 3D operation based on the sketch.
- To import a mesh run the following menu commands in the Part workbench: Create shape from mesh, followed by Convert to solid, followed by Refine shape.
- Use the Array tool in the Draft workbench to create multiple copies of an object with a certain spatial distribution (grid-shaped or radial).
- Use the Sweep tool in the Part workbench to create hose/pipe shaped parts. You will need to prepare a sketch that serves as the cross section of the part that is constructing by sweeping.
- There are two types of chamfer and fillet tools. In the Part Design workbench they operate on the single selected edge. In the Part workbench they allow you select multiple edges from the set of edges of the selected part.
- Make sure to adjust the font size when creating annotation text in the Draft workbench. The initial size may be so small that you can't see the text.
- How to use the Sweep tool: Create two sketches, one being the profile that will be swept, the other one being the path along which to sweep the profile. Click on the Sweep button in the Part workbench, in the left hand table select the profile that you prepared, click on the right arrow button to add it to the Sweep table, ignore the Sweep Path button, click on the parts of the sketch that you prepared as the sweep path while holding the CTRL key pressed, finally click on OK.