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草图工作台中的创建弧工具

From FreeCAD Documentation
This page is a translated version of the page Sketcher CreateArc and the translation is 15% complete.
Outdated translations are marked like this.

通过圆心创建圆弧

菜单位置
Sketch → 草图几何体 → 通过圆心创建圆弧
所属工作台
Sketcher
默认快捷键
G A
版本介紹
-
参阅
创建圆

描述

此工具通过用户拾取的三个点:中点、圆周上的起始角度与圆周上的终点角度来绘制一条弧。

Arc created in Center mode with automatically applied constraints defined by entering all On-View-Parameters

如何使用

See also: Drawing aids.

Pos-OVP = Positional On-View-Parameters. introduced in 1.0
Dim-OVP = Dimensional On-View-Parameters. introduced in 1.0

  • 在3D视图中的空白区域或从一个已存在对象上(一定要激活TaskView中的自动约束(auto constraints)。译注:0.18版中自动约束设置位于底图的首选项中)拾取对应点。
  • Esc键或点击鼠标右键来退出此功能。

Notes

  • An arc has 5 degrees of freedom (DoF). Constraining its end points and its center to other existing and static points with coincident constraints would need 3×2=6 DoF. To avoid over-constraining, 2 points of the arc can be coincident to these existing points, but the last constraint needs to consume only one DoF. It can be a horizontal or vertical constraint for example. If both end points have coincident constraints, applying a radius dimension or equal constraint to define the radius of the arc can also work.