SketchUp Arc Tools: Creating precise arcs

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Creating precise arcs

Use the Measurements Toolbar to enter exact lengths for the chord length, bulge distance, radius, number of segments, or angle.

Use the Measurements Toolbar to enter exact lengths for the chord length, bulge distance, radius, or 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

For 2-Point Arc tool: 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.

For the 3-Point Arc tool: Typing a Length value in the Measurements Toolbar specifies the linear length between the first point and the second point.

Specifying a bulge distance

For 2-Point Arc tool: 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.

After drawing the arc, select the Move tool, then click and drag the mid-point of the arc to adjust the Bulge. You can type a specific value in the Measurements Toolbar.

Specifying a radius

For 2-Point Arc:
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.

For Arc and Pie tools:
You can specify an arc radius in the Measurements Toolbar after your first click. You don't need to include the letter r.

After drawing the arc, select the arc, then context click on the arc and select Entity Info. You can adjust the Radius field in Entity Info as needed.

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)

Specifying the dynamic number of segments

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)

Specifying an angle (for 3-Point Arc, Arc, and Pie tools only)

The Measurements Toolbar's label indicates 'Angle' after your second click when drawing the 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.

Specifying the axis of rotation (for Arc and Pie tools only)

Just like the Rotate and Protractor tool, you can click and drag the first point to define the axis of rotation. This is especially helpful if you need to rotate on an axis that isn't on the red, green, or blue planes.