This tool draws an arc of ellipse by picking four points: the center, the end of major radius, the start point and the end point.
When starting the tool, the mouse pointer changes to a white cross with a red ellipse arc icon. Besides are coordinates shown in real time.
The sequence of clicks is indicated by yellow arrows with numbers. C is the center, a - major diameter, b - minor diameter, F1, F2 are foci.
- Press the Create an arc of ellipse button.
- First click in 3D view sets ellipse center. Second click sets the first radius and orientation of the ellipse. Third click sets the other radius and the start of the arc. The fourth click sets the end of the arc.
- After the fourth click, the arc of ellipse is created, together with a set of construction geometry aligned to it (major diameter, minor diameter, two foci). The construction geometry can be manually deleted if not needed, and recreated later. See Internal Alignment Constraint and Sketcher Show Hide Internal Geometry.
- Pressing ESC or clicking the right mouse button cancels the function.
- Major and minor axes of underlying ellipse are strict and cannot be swapped by resizing. The underlying ellipse must be rotated to swap the axes.
- Unlike ellipse that can be constrained to become a circle, ellipse arc cannot represent an arc of circle.
- Moving the arc of ellipse by edge is the same as moving ellipse's center.
- General: Create sketch, Edit sketch, Leave sketch, View sketch, View section, Map sketch to face, Reorient sketch, Validate sketch, Merge sketches, Mirror sketch, Stop operation
- Sketcher geometries: Point, Line, Arc, Arc by 3 points, Circle, Circle by 3 points, Ellipse, Ellipse by 3 points, Arc of ellipse, Arc of hyperbola, Arc of parabola, B-spline, Periodic B-pline, Polyline, Rectangle, Centered rectangle, Rounded rectangle, Triangle, Square, Pentagon, Hexagon, Heptagon, Octagon, Regular polygon, Slot, Fillet, Trim, Extend, Split, External geometry, Carbon copy, Toggle construction geometry
- Sketcher constraints:
- Geometric constraints: Coincident, Point on object, Vertical, Horizontal, Parallel, Perpendicular, Tangent, Equal, Symmetric, Block
- Dimensional constraints: Lock, Horizontal distance, Vertical distance, Distance, Radius, Diameter, Radiam, Angle, Snell's law, Internal alignment
- Constraint tools: Toggle driving/reference constraint, Activate/deactivate constraint
- Sketcher tools: Select unconstrained DoF, Close shape, Connect edges, Select associated constraints, Select associated geometry, Select redundant constraints, Select conflicting constraints, Show/hide internal geometry, Select origin, Select vertical axis, Select horizontal axis, Symmetry, Clone, Copy, Move, Rectangular array, Remove axes alignment, Delete all geometry, Delete all constraints
- Sketcher B-spline tools: 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, Convert geometry to B-spline, Increase B-spline degree, Decrease B-spline degree, Increase knot multiplicity, Decrease knot multiplicity, Insert knot
- 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, Arch, Draft, FEM, Image, Inspection, Mesh, OpenSCAD, Part, PartDesign, Path, Points, Raytracing, Reverse Engineering, Sketcher, Spreadsheet, Start, Surface, TechDraw, Test Framework, Web
- Deprecated or unmaintained workbenches: Complete, Drawing, Robot