PartDesign Workbench/es

El banco de trabajo de Diseño de Piezas proporciona herramientas avanzadas para modelar piezas sólidas complejas y está basado en una metodología de edición de operaciones. Dicha metodología es especialmente útil para la creación de piezas mecánicas, aunque no está limitada a ese único fin. El banco de trabajo de Diseño de Piezas está intrínsecamente vinculado con el banco de trabajo Croquizador.

Metodología de edición de operaciones
Mientras el Banco de trabajo de Pieza y otros bancos de trabajo de FreeCAD permiten crear piezas mediante la combinación de formas, el banco de trabajo de diseño de piezas se basa en operaciones. Una operación modifica la forma de una pieza.

La primera operación es conoce como operación base. A medida que se van añadiendo operaciones, cada operación toma la forma resultante de la operación anterior y añade o quita material, creando una dependencia lineal entre cada operación y la siguiente. Desde el punto de vista de las operaciones sustractivas, esta metodología se asemeja al proceso de fabricación. Por ejemplo, a un bloque se le hace un corte a un lado, posteriormente a otro lado, luego se perforan agujeros, a continuación se redondean bordes, etc.

Todas las operaciones aparecen listadas de forma secuencial en el árbol del proyecto y pueden ser editadas en cualquier momento. El resultado de la última operación, aquella que ocupa el lugar inferior en la lista de operaciones, es el que determina la forma de la pieza final.

Las operaciones se clasifican en las siguientes categorías:


 * Basadas en perfil: Estas operaciones utilizan un perfil como punto de partida para definir la forma del material que va a ser añadido (operación aditiva) o eliminado (operación sustractiva). El perfil puede ser un croquis, una cara plana de la geometría (en cuyo caso el perfil se extrae de sus aristas), una forma unida o un objeto del banco de trabajo Draft que haya sido incluido en el cuerpo activo con anterioridad.


 * Aditiva: añade material al resultado de la operación anterior. Los iconos de las operaciones aditivas se caracterizan porque predomina en ellos el amarillo.


 * Sustractiva: elimina material del modelo existente. Los iconos de las operaciones sustractivas se caracterizan porque predominan en ellos el rojo y el azul.


 * Basadas en Primitivas: son operaciones basadas en primitivas geométricas como por ejemplo el cubo, el cilindro, el cono, el toro, .... Pueden ser tanto aditivas como sustractivas.


 * Operaciones de transformación: aplican transformaciones a una o varias operaciones anteriores (operación reflexión o simetría, patrón de repetición lineal, patrón de repetición polar o una transformada múltiple fruto de la combinación de las anteriores).


 * Operaciones de alteración: operaciones que alteran una arista o una cara determinada, como redondeos, chaflanes o cortes inclinados.


 * Operaciones de procedimiento: se dice de operaciones que no están basadas en croquis, como las operaciones de transformación y las de alteración.

Cuerpo
El Cuerpo es un contenedor que agrupa una secuencia de operaciones formando un único sólido continuo.

¿Qué es un único solido continuo? Es un objeto producido a partir de un único bloque de material. Si el objeto incluye clavos, tornillos, pegamento y soldado, entonces no es un único sólido continuo.

Un documento de FreeCAD puede contener varios cuerpos. Diferentes cuerpos puede combinarse para formar un único sólido continuo.

Cuando una pieza requiere del empleo de varios cuerpos, estos pueden ser agrupados dentro de un contenedor de propósito general llamado contenedor de Pieza. De esta forma todos los cuerpos se pueden trasladar de forma solidaria como si fueran un único objeto.

Gestión de visibilidad de un cuerpo
Un cuerpo queda representado por el resultado de la última operación en él contenida. Por defecto dicha operación es conoce como Punta. Un analogía es la punta del iceberg: sólo la punta es visible sobre el agua, mientras que la mayoría del iceberg permanece oculto bajo el agua. Cuando se añade una nueva operación a un cuerpo, la visibilidad de las anteriores operaciones queda deshabilitada, y la nueva operación se convierte en la punta del cuerpo.

There can only be one feature visible at a time. It is possible to toggle the visibility of any feature in the body, by selecting it in the Model tree and pressing the spacebar, in effect going back in the history of the body.

Body Origin

 * PartDesign tutorial

Moving and Reordering Objects
It is possible to temporarily redefine the tip to a feature in the middle of the Body tree to insert new objects (features, sketches or datum geometry). It is also possible to reorder features under a Body, or to move them to a different Body. Select the object and right-click to get a contextual menu that will offer both options. The operation may be prevented if the object has dependencies in the source Body, such as being attached to a face. To move a sketch to another Body, it should not contain links to external geometry.

Datum Geometry
Datum geometry consists of custom planes, lines, points or externally linked shapes. They can be created for use as reference by sketches and features. There is a multitude of attachment possibilities for datums.

Cross-referencing
It is possible to cross-reference elements from a body in another body via datums. For example the datum shape binder allows to copy over faces from a body as reference in another one. This should make it easy to build a box with fitting cover in two different bodies. FreeCAD helps you to not accidentally link to other bodies and queries your intent.

Attachment
Object attachment is not a specific PartDesign tool, but rather a Part utility introduced in v0.17 that can be found in the Part menu. It is heavily used in the PartDesign workbench to attach sketches and reference geometry to the standard planes and axes of the Body. Very extensive ways of creating datum points, lines and planes are available. Optional attachment offset parameters make this tool very versatile.

More info can be found in the Attachment page.

Advice for creating stable models
The idea of parametric modeling implies that you can change the values of certain parameters and subsequent steps are changed according to the new values. However, when severe changes are made, the model can break. Compared to previous FreeCAD versions breaking can be minimized when you respect the following design principles:


 * Basically, you need to stop mapping sketches to faces - entirely! Place your sketches on standard planes, or on custom datum planes.
 * When creating datum geometry, do not base it on the part topology, base it on standard planes/axes and/or sketches.
 * Use a "master sketch". That is a preferably not too complicated sketch which contains basic geometric elements of your model. These elements can be referenced when modeling subsequent features. Such a master sketch will often be the first sketch in the Body but it doesn't have to be; in fact you don't even have to use it at all for anything else but being referenced.
 * If you inevitably have to reference an intermediate feature, e.g. the result of a thickness operation, use the first reference possible in the list of subsequent features where the referenced geometric element occurs. From FreeCAD 0.17 on you don't have to use the latest feature. If you take an early feature as reference, all changes to intermediate steps won't break your model. And again it is better to reference a sketch than edges and vertices of a solid

The Tools
The Part Design tools are all located in the Part Design menu and the PartDesign toolbar that appear when you load the Part Design workbench.

Part Design Helper tools

 * PartDesign Body.png Create body: Creates a Body in the active document and makes it active.


 * PartDesign_NewSketch.png Create sketch: creates‎ a new sketch on a selected face or plane. If no face is selected while this tool is executed, the user is prompted to select a plane from the Tasks panel. The interface then switches to the Sketcher_Workbench in sketch editing mode.


 * [[Image:Sketcher_EditSketch.png|32px]] Edit sketch: Edit the selected Sketch.


 * [[Image:Sketcher_MapSketch.png‎|32px]] Map sketch to face: Maps a sketch to a previously selected plane or a face of the active body.

Datum tools

 * PartDesign Point.png Create a datum point: creates a datum point in the active body.


 * PartDesign Line.png Create a datum line: creates a datum line in the active body.


 * PartDesign Plane.png Create a datum plane: creates a datum plane in the active body.


 * PartDesign ShapeBinder.png Create a shape binder: creates a shape binder in the active body.


 * PartDesign Clone.png Create a clone: creates a clone of the selected body.

Additive tools
These are tools for creating base features or adding material to an existing solid body.


 * PartDesign_Pad.png Pad: extrudes a solid from a selected sketch.


 * PartDesign_Revolution.png Revolution: creates a solid by revolving a sketch around an axis. The sketch must form a closed profile.


 * PartDesign AdditiveLoft.png Additive loft: creates a solid by making a transition between two or more sketches.


 * PartDesign AdditivePipe.png Additive pipe: creates a solid by sweeping one or more sketches along an open or closed path.


 * Create an additive primitive: adds an additive primitive to the active body.


 * PartDesign AdditiveBox.png Additive box: creates an additive box.


 * PartDesign AdditiveCone.png Additive cone: creates an additive cone.


 * PartDesign AdditiveCylinder.png Additive cylinder: creates an additive cylinder.


 * PartDesign AdditiveEllipsoid.png Additive ellipsoid: creates an additive ellipsoid.


 * PartDesign AdditivePrism.png Additive prism: creates an additive prism.


 * PartDesign AdditiveSphere.png Additive sphere: creates an additive sphere.


 * PartDesign AdditiveTorus.png Additive torus: creates an additive torus.


 * PartDesign AdditiveWedge.png Additive wedge: creates an additive wedge.

Subtractive tools
These are tools for subtracting material from an existing body.


 * PartDesign Pocket.png Pocket: creates a pocket from a selected sketch.


 * PartDesign Hole.png Hole: creates a hole feature from a selected sketch. The sketch must contain one or multiple circles.


 * PartDesign Groove.png Groove: creates a groove by revolving a sketch around an axis.


 * PartDesign SubtractiveLoft.png Subtractive loft: creates a solid shape by making a transition between two or more sketches and subtracts it from the active body.


 * PartDesign SubtractivePipe.png Subtractive pipe: creates a solid shape by sweeping one or more sketches along an open or closed path and subtracts it from the active body.


 * Create a subtractive primitive: adds a subtractive primitive to the active body.


 * PartDesign SubtractiveBox.png Subtractive box: adds a subtractive box to the active body.


 * PartDesign SubtractiveCone.png Subtractive cone: adds a subtractive cone to the active body.


 * PartDesign SubtractiveCylinder.png Subtractive cylinder: adds a subtractive cylinder to the active body.


 * PartDesign SubtractiveEllipsoid.png Subtractive ellipsoid: adds a subtractive ellipsoid to the active body.


 * PartDesign SubtractivePrism.png Subtractive prism: adds a subtractive prism to the active body.


 * PartDesign SubtractiveSphere.png Subtractive sphere: adds a subtractive sphere to the active body.


 * PartDesign SubtractiveTorus.png Subtractive torus: adds a subtractive torus to the active body.


 * PartDesign SubtractiveWedge.png ‎Subtractive wedge: adds a subtractive wedge to the active body.

Transformation tools
These are tools for transforming existing features. They will allow you to choose which features to transform.


 * [[Image:PartDesign_Mirrored.png|32px]] Mirrored: mirrors one or more features on a plane or face.


 * [[Image:PartDesign_LinearPattern.png|32px]] Linear Pattern: creates a linear pattern based on one or more features.


 * [[Image:PartDesign_PolarPattern.png|32px]] Polar Pattern: creates a polar pattern of one or more features.


 * [[Image:PartDesign_MultiTransform.png|32px]] Create MultiTransform: creates a pattern with any combination of the other transformations.

Dress-up tools
These tools apply a treatment to the selected edges or faces.


 * PartDesign Fillet.png Fillet: fillets (rounds) edges of the active body.


 * PartDesign Chamfer.png Chamfer: chamfers edges of the active body.


 * PartDesign Draft.png Draft: applies and angular draft to faces of the active body.


 * PartDesign Thickness.png Thickness: creates a thick shell from the active body and opens selected face(s).

Boolean

 * PartDesign Boolean.png Boolean operation: imports one or more Bodies or PartDesign Clones into the active body and applies a Boolean operation.

Extras
Some additional functionality found in the Part Design menu:


 * Migrate: migrates files created with older FreeCAD versions. If the file is pure PartDesign feature-based, migration should succeed. If the file contains mixed Part/Part Design/Draft objects, the conversion will most likely fail.


 * [[Image:PartDesign_WizardShaft.png|32px]] Shaft design wizard: Generates a shaft from a table of values and allows to analyze forces and moments. The shaft is made with a revolved sketch that can be edited.


 * [[Image:PartDesign_InternalExternalGear.png|32px]] Involute gear: creates an involute gear profile that can be used by a Pad.

Contextual Menu tools

 * PartDesign MoveTip.png Set tip: redefines the tip, which is the feature exposed outside of the Body.


 * Move object to other body: moves the selected sketch, datum geometry or feature to another Body.


 * Move object after other object: allows reordering of the Body tree by moving the selected sketch, datum geometry or feature to another position in the list of features.

Tutorials

 * PartDesign Bearingholder Tutorial I (needs updating)
 * PartDesign Bearingholder Tutorial II (needs updating)
 * PartDesign tutorial (needs updating)
 * Basic Part Design Tutorial (needs updating)

Links

 * What's new in PartDesign Next
 * Updated PartDesign workflow
 * FC v0.17dev: Part Design Next Usecases and Best practices
 * Sandbox:Part Design Next