Sketcher ConstrainCoincident/es

Coincident (unified)

Point on object

Sketcher

Description

The Sketcher ConstrainCoincident tool creates a coincident constraint between points, or (introduced in version 0.21) a concentric constraint between circles, arcs and/or ellipses (by making their centers coincident).

introduced in version 1.0: This tool is replaced by the Sketcher ConstrainCoincidentUnified tool if the Unify Coincident and PointOnObject option is selected in the preferences.

Usage

See also: Drawing aids.

Continue mode

1. Make sure there is no selection.
2. There are several ways to invoke the tool:
   • Press the Constrain coincident button.
   • Select the Sketch → Sketcher constraints → Constrain coincident option from the menu.
   • Use the keyboard shortcut: C.
3. The cursor changes to a cross with the tool icon.
4. Do one of the following:
   • Select two points.
   • Select two edges of circles, arcs, ellipses or arcs of ellipses.
5. A constraint is added.
6. Optionally keep creating constraints.
7. To finish, right-click or press Esc, or start another geometry or constraint creation tool.

Run-once mode

1. Do one of the following:
   • Select two or more points.
   • Select two or more edges of circles, arcs, ellipses or arcs of ellipses.
2. Invoke the tool as explained above.
3. Depending on the selection one or more constraints are added.

Notes

• introduced in version 1.0: Points with Coincident constraints are marked with the Constraint symbols color.

Scripting

The constraint can be created from macros and from the Python console by using the following command:

Sketch.addConstraint(Sketcher.Constraint('Coincident',LineFixed,PointOfLineFixed,LineMoving,PointOfLineMoving))

where :

• Sketch is a sketch object
• LineFixed is the number of the line, that will not move by applying the constraint
• PointOfLineFixed indicates which vertex of LineFixed has to fulfill the constraint
• LineMoving is the number of the line, that will move by applying the constraint
• PointOfLineMoving indicates which vertex of LineMoving has to fulfill the constraint

As the names LineFixed and LineMoving indicate, if both constrained vertices are free to move in any direction, the first one (first to be selected in the Gui) will remain fixed and the other one will move. In the presence of existing constraints, however, both edges may move.

The Sketcher scripting page explains the values which can be used for LineFixed, PointOfLineFixed, LineMoving and PointOfLineMoving, and contains further examples on how to create constraints from Python scripts.

Sketcher

• 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

User documentation

• Getting started
• Installation: Download, Windows, Linux, Mac, Additional components, Docker, AppImage, Ubuntu Snap
• Basics: About FreeCAD, Interface, Mouse navigation, Selection methods, Object name, Preferences, Workbenches, Document structure, Properties, Help FreeCAD, Donate

---

• Help: Tutorials, Video tutorials
• Workbenches: Std Base, Assembly, BIM, CAM, Draft, FEM, Inspection, Material, Mesh, OpenSCAD, Part, PartDesign, Points, Reverse Engineering, Robot, Sketcher, Spreadsheet, Surface, TechDraw, Test Framework

---

• Addons: Addon Manager, External workbenches, Scripting and macros

---

• Hubs: User hub, Power users hub, Developer hub