Vocabulary
Words that come up often in the AI’s answers. The minimum you need if FreeCAD is new to you.
| Term | What it means |
|---|---|
| Body | One part in PartDesign. Sketches and features stack inside it in order. “Make a Body” means start a new part |
| Sketch | A 2D drawing on a plane, made of lines, arcs and circles plus constraints. The raw material for Pad and Pocket |
| Pad | Extrudes a sketch by a thickness, adding material |
| Removes material in the shape of a sketch. Holes and slots | |
| Groove / Revolution | Revolves around an axis to remove / add material. Cylinders, grooves, lips |
| Fillet / Chamfer | Rounds / bevels an edge. R2, C0.5 |
| Helix | Threads and helical grooves. Pitch, height, handedness |
| Feature | One step such as a Pad or Pocket. They appear in the Body tree in order |
| Tip | The feature in a Body that represents «the result so far». Usually the last one |
| Constraint | A condition fixing the position or size of sketch elements — horizontal, vertical, coincident, length, diameter, equal and so on. The numbers match the constraint panel |
| DoF (degrees of freedom) | How much movement the constraints have not pinned down yet. Zero means fully constrained (green). Anything left and it moves when you drag it |
| Conflicting | Constraints that contradict each other (length 40 and 42 on the same line). The sketch turns red |
| Redundant | Two constraints saying the same thing. There is a solution, but you get a warning |
| Open vertex | A gap where an outline should close. Two vertices per gap. A common reason a Pad fails |
| Recompute | Recalculating geometry to reflect a change. Objects that fail become Invalid (red) |
| Placement | An object’s position and orientation (translation plus rotation) |
| Link | An object referencing another Body or a part in another file. For placing the same part in several positions. If the file is missing you get a «broken link» |
| BaseFeature | A lump imported from a STEP, inserted as the base of a Body. You cannot edit the original, but you can stack Pockets on top |
| Params (Spreadsheet) | The sheet where the AI puts dimensions under names. Change thickness and the Pad follows |
| STEP | The precise solid format a vendor sends you. It has faces and edges, so holes and interference can be analysed |
| STL / OBJ / 3MF | Triangle meshes. No faces, no solid — they have to be «redrawn» before they can be analysed |
| bbox | The minimum and maximum coordinates of the box enclosing an object. For checking size |
| Cut (difference) | The fragments present in the original but absent from the rebuild (missing), or the reverse (extra). Tells you where you went wrong |
| Verdict | The comparison result. identical (under 0.001 %) / match (under 0.1 %) / different |
| von Mises stress | The equivalent stress in the material. Compared against yield strength: safety factor = yield / maximum stress |
| TechDraw | FreeCAD’s 2D drawing workbench. Pages, views, dimensions, title blocks |
| Workbench | A mode grouping FreeCAD’s tools. Part Design, Sketcher, TechDraw, FEM, CAD X-ray |