Part and PartDesign
Overview
There has been much discussion of this over the years about the differences and ramifications of using the Part and Part Design workbenches.
It is a good idea to use one or the other until the user is comfortable with one, then learn the other. It is also typically recommended that new users not mix them until the ramifications are of doing so are understood.
Let's talk about those ramifications.
Part Workbench Concepts
It is often said Part WB is more CSG style modeling. This is where the operator combines various primitives to end up with a lump in the desired shape. (In fact Part WB goes one step further than just primitives and allows the operator to use a sketch+extrude operation to create random shapes as well.) When each primitive or shape is created, it has no relationship to other objects created, it is a single solitary solid.
This condition remains so, until, the operator uses some operation to combine them (typically a Boolean that adds or subtracts them).
The take away is the single solitary solid bit and the combining them bit.
Part Design Workbench Concepts
In Part Design WB the Body object represents a single solitary cumulative solid. The first lump created under the Body (be it a Pad from a sketch, or a BaseFeature from outside the Body) represents a lump of raw material that will be further processed to refine it to the desired final shape (solid). It is cumulative in the sense that each operation adds or removes material. The lowest/last operation (the current Tip of the Body) is the current state. Any other feature under the Body but above the Tip, does not represent a complete/stand alone solid. Only the Body (basically a proxy for the tip) or the Tip represent a complete solid.
This image shows a Body. It is a cumulative solid that consists of a padded sketch and a cone primitive. This is a single solid. Neither the pad or the cone can exist separately.
(Another thing mentioned often is a Body MUST be a single contiguous solid. This means all geometry created by a feature in the Body must touch it's predecessor.)
The Ramifications
People get caught when they attempt to use some feature under the Body (rather than the Body itself) as one selection of a Part WB Boolean operation. This is a problem, because the selected feature does not represent a complete solid.
In a sense, from a Part WB standpoint, the Body represents another primitive. So, using a Body (remember it is a proxy for the tip) and a Part WB object to do a Boolean is valid. But the resulting object is a Part WB object. And, thus Part Design WB tools can't be used on it any longer.
And, it can get even more complicated. If you create a new Body and drag the result from the previous paragraph into it, a BaseObject is created. And you can go off an use the Part Design WB tools on it.
Conclusion
Part and Part design workbenches can be used together with some care, creating quite complex models.
- Primitives: Box, Cylinder, Sphere, Cone, Torus, Tube, Create primitives, Shape builder
- Creation and modification: Extrude, Revolve, Mirror, Scale, Fillet, Chamfer, Make face from wires, Ruled Surface, Loft, Sweep, Section, Cross sections, 3D Offset, 2D Offset, Thickness, Projection on surface, Attachment
- Boolean: Make compound, Explode Compound, Compound Filter, Boolean, Cut, Fuse, Common, Connect, Embed, Cutout, Boolean fragments, Slice apart, Slice, XOR
- Structure tools: Part, Group
- Helper tools: Create body, Create sketch, Attach sketch, Edit sketch, Validate sketch, Check geometry, Create a sub-object(s) shape binder, Create a clone, Create a datum plane, Create a datum line, Create a datum point, Create a local coordinate system
- Modeling tools:
- Additive tools: Pad, Revolution, Additive loft, Additive pipe, Additive helix, Additive box, Additive cylinder, Additive sphere, Additive cone, Additive ellipsoid, Additive torus, Additive prism, Additive wedge
- Subtractive tools: Pocket, Hole, Groove, Subtractive loft, Subtractive pipe, Subtractive helix, Subtractive box, Subtractive cylinder, Subtractive sphere, Subtractive cone, Subtractive ellipsoid, Subtractive torus, Subtractive prism, Subtractive wedge
- Boolean: Boolean operation
- Dress-up tools: Fillet, Chamfer, Draft, Thickness
- Transformation tools: Mirrored, Linear Pattern, Polar Pattern, Create MultiTransform, Scaled
- Extras: Migrate, Sprocket, Involute gear, Shaft design wizard
- Context menu: Set tip, Move object to other body, Move object after other object, Appearance, Color per face
- Preferences: Preferences, Fine tuning
- General: Create sketch, Edit sketch, Attach sketch, Reorient sketch, Validate sketch, Merge sketches, Mirror sketch, Leave sketch, View sketch, View section, Toggle grid, Toggle snap, Configure rendering order, Stop operation
- Sketcher geometries: Point, Polyline, Line, Arc, Arc by 3 points, Arc of ellipse, Arc of hyperbola, Arc of parabola, Circle, Circle by 3 points, Ellipse, Ellipse by 3 points, Rectangle, Centered rectangle, Rounded rectangle, Triangle, Square, Pentagon, Hexagon, Heptagon, Octagon, Regular polygon, Slot, Arc slot, B-spline by control points, Periodic B-spline by control points, B-spline by knots, Periodic B-spline by knots, Toggle construction geometry
- Sketcher constraints:
- Dimensional constraints: Dimension, Horizontal distance, Vertical distance, Distance, Auto radius/diameter, Radius, Diameter, Angle, Lock
- Geometric constraints: Coincident (unified), Coincident, Point on object, Horizontal/vertical, Horizontal, Vertical, Parallel, Perpendicular, Tangent or collinear, Equal, Symmetric, Block
- Other constraints: Refraction (Snell's law)
- Constraint tools: Toggle driving/reference constraint, Activate/deactivate constraint
- Sketcher tools: Fillet, Chamfer, Trim, Split, Extend, External geometry, Carbon copy, Select origin, Select horizontal axis, Select vertical axis, Array transform, Polar transform, Scale transform, Offset geometry, Symmetry, Remove axes alignment, Delete all geometry, Delete all constraints
- Sketcher B-spline tools: Convert geometry to B-spline, Increase B-spline degree, Decrease B-spline degree, Increase knot multiplicity, Decrease knot multiplicity, Insert knot, Join curves
- Sketcher visual: Select unconstrained DoF, Select associated constraints, Select associated geometry, Select redundant constraints, Select conflicting constraints, Show/hide circular helper for arcs, Show/hide B-spline degree, Show/hide B-spline control polygon, Show/hide B-spline curvature comb, Show/hide B-spline knot multiplicity, Show/hide B-spline control point weight, Show/hide internal geometry, Switch virtual space
- Additional: Sketcher Dialog, Preferences, Sketcher scripting
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