PartDesign Legacy/zh

The Part Design Workbench provides tools for modelling complex solid parts and is based on a Feature editing methodology to produce a single contiguous solid. It is intricately linked with the Sketcher Workbench.

What is a single contiguous solid? This is an item like a casting or something machined from a single block of metal. If the item involves nails, screws, glue or welding, it is not a single contiguous solid. As a practical example, PartDesign would not be used to model a wooden chair, but would be used to model the subcomponents (legs, slats, seat, etc). The subcomponents are combined using the Assembly, Part or Draft workbench.



Basic Workflow
The sketch is the building block for creating and editing solid parts. The workflow can be summarized by this: a sketch containing 2D geometry is created first, then a solid creation tool is used on the sketch. At the moment the available tools are: More tools are planned in future releases.
 * [[Image:PartDesign_Pad.png|32px]] Pad which extrudes a sketch
 * [[Image:PartDesign_Pocket.png|32px]] Pocket which creates a pocket on an existing solid
 * [[Image:PartDesign_Revolution.png|32px]] Revolution which creates a solid by revolving a sketch along an axis
 * [[Image:PartDesign_Groove.png|32px]] Groove which creates a groove in an existing solid

A very important concept in the PartDesign Workbench is the sketch support. Sketches can be created on standard planes (XY, XZ, YZ and planes parallel to them) or on a planar face of an existing solid. For this last case, the existing solid becomes the support of the sketch. Several tools will only work with sketches that have a support, for example, Pocket - without a support there would be nothing to remove material from!

After solid geometry has been created it can be modified with chamfers and fillets or transformed, e.g. mirrored or patterned.

The PartDesign Workbench is meant to create a single, connected solid. Multiple solids will be possible with the Assembly workbench.

As we create a model in the Part Design Workbench, each feature takes the shape of the last one and adds or removes something, creating linear dependencies from feature to feature as the model is created. Hence a "Cut" feature is not only the cut hole itself, but the whole part with the cut. As a new feature is added to the model, FreeCAD turns off visibility of the old features. The user usually should only have the newest item (feature) in the model tree visible, because otherwise the other phases of the model overlay each other, and holes are filled in by the earlier model features that didn't yet have those holes.

To toggle visibility of an object on or off, select it in the hierarchy tree and press the Spacebar. Usually everything but the last item in the hierarchy tree should be greyed out and therefore not visible in the 3D view.

The Tools
The Part Design tools are all located in the Part Design menu that appears when you load the Part Design module.

They include the Sketcher Workbench tools, since the Part Design module is so dependent on them.

Extras
Some optional functionality that has been created for the PartDesign Workbench:


 * [[Image:PartDesign_WizardShaft.png|32px]] Shaft design wizard: Generates a shaft from a table of values and allows to analyze forces and moments


 * [[Image:PartDesign_InternalExternalGear.png|32px]] Involute gear: allows you to create gear

Properties
There are two types of feature properties accessible through tabs at the bottom of the property editor:
 * : properties related to the "visual" display of an object.
 * : properties related to the "physical" parameters of an object.

Data


Every feature has a placement that can be controlled through the Data Properties table. It controls the placement of the part with respect to the coordinate system. NOTE: The placement properties do not affect the physical dimensions of the feature, but merely its position in space! If you select the title Placement, a button with appears to the right. Clicking this button, opens the Tasks_Placement options window.

An angle is set here, and the axis that the angle acts upon is set with the axis property. The feature is rotated by the specified angle, about the specified axis. A usage example might be if you created a revolution feature as required, but then needed to rotate the whole feature by some amount, in order to allow it to line-up with another pre-existing feature.

The exact value of rotation comes from the angle property (above). This property takes three arguments, which are passed as numbers in the x, y, and z boxes in the tool. Setting a value for more than one of the axes will cause the part to be rotated in each axis, by the angle value multiplied by the value for the axis. For example, with an angle of 15° set, specifying a value of 1.0 for x, and 2.0 for y will cause the finished part to be rotated 15° in the x-axis AND 30° in the y-axis.

This takes three arguments, which are passed as numbers to the x, y, and z boxes in the tool. Setting a value for more than one of the boxes will cause the part to be translated by the number of units along the corresponding axis.



PS: The displayed properties can vary, depending on the tool used.

Tutorials
Only for a development version of FreeCAD that is not currently available as a binary or installer:
 * PartDesign Bearingholder Tutorial I
 * PartDesign Bearingholder Tutorial II


 * PartDesign tutorial


 * Basic Part Design Tutorial
 * Sketcher tutorial