FreeCAD: Part Design, Assembly, Exploded View, and TechDraw Workbenches

Spent time going through four workbenches that together form a complete FreeCAD workflow — from parametric solid through assembly, documentation, and formal drawing.

Part Design Workbench

The primary workbench for building parametric mechanical solids. Geometry is defined through a feature tree: a sequence of sketches and operations (Pad, Pocket, Revolve, Fillet, Chamfer, etc.) that build on each other from base to finished solid.

Key concepts:

• Body — the container for a single solid; all features belong to one Body
• Sketch — constrained 2D profile drawn on a plane or face; the foundation of most features
• Pad / Pocket — extrude a sketch outward or cut it inward
• Revolve — sweep a sketch around an axis to create rotational geometry
• Fillet / Chamfer — edge finishing operations applied after primary geometry is complete

The feature tree is fully parametric: editing any earlier sketch or operation propagates changes through all downstream features automatically.

Assembly Workbench

Brings individual Part Design bodies or imported components together into a single assembly document. Uses joints to define constraints between parts.

Joint types covered:

• Fixed — locks one part in place; every assembly needs at least one fixed part as the ground
• Revolute — allows rotation around a single axis (hinges, shafts)
• Cylindrical — rotation + translation along the same axis
• Slider — translation along an axis only
• Ball — rotation in any direction around a point

The workflow: insert components → apply joints between them → the solver positions and constrains each part relative to the others. Under-constrained parts float; over-constrained parts throw solver errors.

Exploded View Workbench

Works on top of an existing assembly to create exploded diagrams — parts separated along defined axes to show how the assembly comes apart.

The key tool is Create Exploded View, which lets you select parts and define a direction and distance to move them. Multiple explosion steps can be sequenced and animated. The result is stored as a named view that can be referenced in TechDraw.

Useful for documentation and assembly instructions, not for modifying geometry.

TechDraw Workbench

Produces 2D technical drawings from 3D models — dimensioned orthographic projections, section views, and detail views on a formal drawing sheet.

Workflow:

1. Create a page using a template (A4, A3, etc.)
2. Insert a view — drag a Part Design body or assembly onto the page; set the projection angle (first-angle or third-angle)
3. Add projection group for standard orthographic views (front, top, side) in one step
4. Dimension — select edges or vertices and insert linear, radial, or angular dimensions
5. Section view — define a cut plane and TechDraw generates the cross-section automatically

What Clicked

These four workbenches form a natural sequence: Part Design → build the solid → Assembly → constrain parts together → Exploded View → document how it comes apart → TechDraw → produce the formal drawing. Each workbench hands off to the next without rebuilding geometry. Understanding this pipeline makes it clearer when to reach for which tool.