Working with an Angular Dimension Object on a PCB in Altium Designer

Parent page: PCB Objects

A placed Angular Dimension

Summary

An angular dimension is a group design object. It allows for the dimensioning of angular distances.

Availability

Angular dimension objects are available for placement in the PCB Editor only. Use one of the following methods to access a placement command:

• Choose Place » Dimension » Angular from the main menus.
• Locate and use the Angular command () on the Active Bar.

• Click the  button on the Place Dimension drop-down () of the Utilities toolbar.
• Right-click in the workspace then choose the Place » Dimension » Angular command from the context menu.

Placement

After launching the command, the cursor will change to a cross-hair and you will enter dimension placement mode. Placement is made by performing the following sequence of actions:

1. Position the cursor over the first reference object then click or press Enter to anchor the first dimension reference (the inside reference).
2. Move the cursor to the next required position associated with the first object being dimensioned then click or press Enter to anchor the second dimension reference (the outside reference).
3. Position the cursor over the second reference object then click or press Enter to anchor the third dimension reference (the inside reference).
4. Move the cursor to the next required position associated with the second object being dimensioned then click or press Enter to anchor the fourth dimension reference (the outside reference).
5. Place the dimension text for the angle as desired then click or press Enter to complete placement.
6. Continue placing further angular dimensions or right-click or press Esc to exit placement mode.

Additional actions that can be performed during placement are:

• Press the + and - keys (on the numeric keypad) to cycle forward and backward through all visible layers in the design to change placement layer quickly.

Graphical Editing

This method of editing allows you to select a placed angular dimension object directly in the workspace and change properties such as the position of its text and its reference points graphically.

When an angular dimension object is selected, the following editing handles are available:

A selected Angular Dimension

• Click & drag A or B to change the position of the dimension text and extension line length.
• Click & drag C or E to detach the dimension from the first reference object.
• Click & drag D or F to detach the dimension from the second reference object.

1. An angular dimension object can be moved in the following ways:
   1. Selecting both the dimension object and the objects that are being dimensioned - The whole can be dragged to a new location as required.
   2. Selecting an object that is being dimensioned only - The dimension text will follow the object in its alignment plane only. The dimension extensions will expand/contract to keep the relationship between dimension and object being dimensioned.
   3. Selecting the dimension object only -  It is important to note that the dimension cannot be moved on its own if it is referenced by a design object. To move the dimension only, it must first be detached from the objects it is dimensioning.
2. The dimension's value automatically updates as its start or end points are moved. Likewise, if the position of an object that a reference point of the dimension is anchored to is changed, the dimension will update and expand/contract to reflect this.
3. If the angular dimension object is totally non-referenced (i.e. it is not attached to any reference design objects), click anywhere on it away from editing handles then drag to reposition it. While dragging, the angular dimension can be rotated or mirrored:
   1. Press the Spacebar to rotate the angular dimension counterclockwise or Shift+Spacebar for clockwise rotation. Rotation is in accordance with the value for the Rotation Step defined on the PCB Editor – General page of the Preferences dialog.
   2. Press the X or Y keys to mirror the angular dimension along the X-axis or Y-axis.

Non-Graphical Editing

The following methods of non-graphical editing are available:

Via the Angular Dimension Dialog or Properties Panel

Properties page: Angular Dimension Properties

This method of editing uses the associated Angular Dimension dialog mode and Properties panel to modify the properties of an Angular Dimension object. 

   The Angular Dimension dialog on the left and the Angular Dimension mode of the Properties panel on the right.

During placement, the Angular Dimension mode of the Properties panel can be accessed by pressing the Tab key. Once the Angular Dimension is placed, all options appear.

After placement, the Angular Dimension dialog can be accessed by:

• Double-clicking on the placed Angular Dimension object.
• Placing the cursor over the Angular Dimension object, right-clicking then choosing Properties from the context menu.

After placement, the Angular Dimension mode of the Properties panel can be accessed in one of the following ways:

• If the Properties panel is already active, by selecting the Angular Dimension object.
• After selecting the Angular Dimension object, select the Properties panel from the Panels button in the bottom right section of the workspace, or by selecting View » Panels » Properties from the main menu.

Editing via the PCB List Panel

Panel page: PCB List, PCB Filter

The PCB List panel allows you to display design objects from one or more documents in tabular format, enabling quick inspection and modification of object attributes. Used in conjunction with appropriate filtering - by using the PCB Filter panel, or the Find Similar Objects dialog - it enables the display of just those objects falling under the scope of the active filter – allowing you to target and edit multiple design objects with greater accuracy and efficiency.

Tips

1. When the reference or references to which a dimension object is attached are deleted, a dialog will open asking whether the dimension should also be deleted. If the dimension is not deleted, it remains in the workspace but non-referenced.
2. Angular dimensions are group objects consisting of text and track segments. They can be converted to their set of primitive objects by choosing Tools » Convert » Explode Dimension to Free Primitives from the main menus. Once exploded, a dimension object can no longer be manipulated as a group object.