Recommended test
Keep a circle diameter and anchor its centre, then try to drag it.
- Draw a circle in Sketch mode and select it with Select.
- Under Dimensions & constraints, choose Diameter, enter a value and choose Keep dimension.
- Add Fix point to its centre and check the constraint status.
- Try a drag, change the kept diameter and verify that size changes while the centre stays anchored.
- Save and reopen to verify the retained constraints.
Edit a value or keep it
Selecting sketch geometry opens its properties. Changing a property edits the drawing once. A Driving dimension keeps that value as a relationship for later edits.
In Dimensions & constraints, select an available field, enter its value and choose Keep dimension. Depending on the selected entity, fields include length, angle, radius, diameter, width and height. Angles are in degrees; lengths use the shown CAD unit.
Edit a kept dimension in the constraint list. Enter or leaving the field applies a valid value; Escape restores the previous input. Removing a constraint keeps the current geometry while freeing that relationship.
Add geometric relationships
Choose Add relationship, select the curves and any required endpoints or centres, then use Add constraint. Select one curve and Shift-click another to fill both curve fields.
| Relationship | Purpose |
|---|---|
| Coincident | Keep two selected points together. |
| Point on curve | Keep a point on the chosen curve. |
| Midpoint | Attach a point to a supported curve midpoint. |
| Horizontal / Vertical | Align geometry with the sketch’s U/V directions. |
| Parallel / Perpendicular | Control the directions of two supported curves. |
| Tangent | Keep supported curves tangent. |
| Fix point | Anchor an endpoint or centre in the sketch. |
Available combinations depend on the selected geometry. Read a conflict or unsupported-selection message before adding more constraints.
Read the status
The panel reports Under-constrained with remaining degrees of freedom, or Fully constrained. Green curves indicate fully constrained geometry.
A dimensioned object can still move if its placement is free. Anchor a point when the sketch must stay in a fixed position. Conversely, remove an unnecessary constraint if the intended edit conflicts with an existing one. Redundant relationships do not add useful control.
Splines and linked sketch fillets keep their own editing tools. Release a fillet relationship before constraining its individual supporting curves. The solver does not treat every spline control point as a fully supported constrained entity.
Use construction geometry and settings
Draw helpers with Construction geometry in the sketch header. Construction lines, circles and arcs can participate in compatible constraints and snapping while being excluded from solid regions.
Open Sketch settings with the gear for grid spacing, grid and body-reference visibility, opacity and dimension display. Grid settings are per plane; the 3D workspace uses its own grid spacing.
Constraints and source geometry save with the sketch. A finished solid does not regenerate automatically when those constraints change: use a new explicit solid operation to create the revised result.