SketchUp Arc Tool: Creating precise arcs

Creating precise arcs

The Measurements Toolbar displays the chord length of the arc (after setting the starting point), then the bulge distance (after setting the ending point). Use the Measurements Toolbar to enter exact lengths for the chord length, bulge distance, radius value, and number of segments.

Note: SketchUp will use the current file units setting if you only type in a numerical value. You can also specify either Imperial (1'6") or Metric (3.652m) units at any time, regardless the file's units setting. Units are set within the Units panel of the Model Info dialog box.

Entering a chord length

The Measurements Toolbar's label indicates 'Length' after you place the starting point of an arc. Type the chord length into the Measurements Toolbar, after placing the starting point of the arc, and press the Enter (Microsoft Windows) or Return (Mac OSX) key. Specify a negative value, such as -6.5", to indicate that you want the length to apply in an opposite direction to the current drawing direction.

Specifying a bulge distance

The Measurements Toolbar's label indicates 'Bulge' after you place the ending point of an arc. Type the bulge length in the Measurements Toolbar, after placing an ending point, and press the Enter (Microsoft Windows) or Return (Mac OS X) key. You can also enter the bulge distance after the creation of the arc as long as 'Bulge' is displayed as the Measurements Toolbar label. Negative bulge values can also be used to create an arc in an opposite direction to the current drawing direction.

Specifying a radius

You can specify an arc radius instead of a bulge distance. Type the desired radius in the Measurements Toolbar, followed by the letter r and press the Enter (Microsoft Windows) or Return (Mac OS X) Key. You can perform this action either during or immediately following the creation of the arc. For example: 24r or 3'6"r or 5mr.

Specifying the number of segments

You can also specify the number of segments in an arc. Type the number of segments in the Measurements Toolbar, followed by the letter s, and press the Enter (Microsoft Windows) or Return (Mac OS X) key. You can perform this action either during or immediately following the creation of the arc. For example: 20s.

Specifying the dynamic number of segments (for Arc and Pie tools only)
You can also specify the dynamic number of segments (Circle Sides) in an arc. When specifying the dynamic number of segments, the number of segments in an arc will be proportionate to the arc central angle. Type the number of segments in the Measurements Toolbar, followed by the letter c, and press the Enter (Microsoft Windows) or Return (Mac OS X) key. You can perform this action either during or immediately following the creation of the arc. For example: 20c With this setting a 90 degree arc will have 5 (20 * 90/360) segments

Specifying an angle (for Arc and Pie tools only)

The Measurements Toolbar's label indicates 'Angle' after you place the starting point of an arc. Type the angle value (in degrees) in the Measurements Toolbar after placing a starting point, and press the Enter (Microsoft Windows) or Return (Mac OS X) key. You can also enter the angle value after the creation of the arc as long as 'Angle' is displayed as the Measurements Toolbar label. Negative angle values can also be used to create an arc in an opposite direction to the current drawing direction.