Arc Center

Introduction

This topic will explain the Arc Center function, will explain where to find the function, and explain the options found in it. This topic will also give a brief description of Dynamic Drawing, the Snap Increment function, explain creation with quick steps and an example, and provide links to related topics.

The Arc Center Function

The Arc Center function is used to create arcs of a specified radius, and start and end angles, by defining the origin of the arc. This can be accomplished by sketching, picking a point or snap point in the graphics area, or entering the coordinates of the origin. You can also use the Multi-Picking option and select multiple points in the graphics area at once to create the specified arc on each selected point.

Dynamic Drawing

This function supports Dynamic Drawing which allows you to use a combination of sketching and data entry to create the entities. After initially sketching the entity, it becomes an active entity, which is an entity that is in Modify Mode. Entities in Modify Mode display in the current Entity color, but displays with a greater line thickness to make them easier to identify. Active entities can be modified using data entry. The benefit of Dynamic Drawing is that you can quickly sketch a point to get the approximate result and then use data entry to update to the exact dimensions, and coordinate values as needed.

 

Entities in Modify Mode

Final Entities

 

In the images above, we see entities which are still in Modify Mode, followed by those same entities after they are finalized.

Snap Increment

This function support the use of the snap increment when selecting the location of the entities. The snap increment allows you to get precise results when using mouse selection and helps to reduce data entry modifications.

 

To learn more, view Snap Increment.

To open Arc Center:

 

  • In the Entity group, of the Create 2D ribbon, click the down arrow under Arc, and select Arc Center.

 

The parameters display in the Data Entry Manager.

The Data Entry Parameters

Arc

 

Creation Option

 

                 

 

Parameters

 

Center Selection Mode

 

  • Single Picking/Coordinates - the axis will be defined manually, with an existing axis, or a defined vector.
    Multi-Picking - the axis will be defined by selecting a line, or surface edge.

    The following parameters vary depending on the Center Selection Mode option that is chosen: 

 

Single Picking/Coordinates

 

Center

 

  • X - sets the location of the arc center along the X axis.
  • Y - sets the location of the arc center along the Y axis.
  • Z - sets the location of the arc center along the Z axis.

 

Multi-Picking

 

Selected Geometry

 

(Delete) - removes the highlighted item from the list.

(Delete All) - removes all entities from the list.
The list box will list the entities currently selected for the function.

 

 


 

 

 

Dimensions

 

  • Radius - sets the distance from the center of the arc to the circumference.

  • Start Angle - sets the rotation angle at which the arc begins measured from the positive X-axis.

  • End Angle - sets the rotation angle at which the arc ends measured from the positive X-axis.

 

  • Other Half - allows you to choose the other half of the specified angle range.

     

  • OK - finalizes the function.
  • Cancel - exits the function.

Quick Steps - Arc Center

Single Picking/Coordinates

 

  1. Open the function and click a snap point or anywhere in the graphics area to set the arc center.

    You can modify the snap increment value or turn it off while selecting the arc center and the arc radius.

    The arc changes from the Preview color to the Entity color and displays with a greater line thickness to show it is the active entity.

      

  2. With Dynamic Drawing, you can update the Data Entry parameters to modify the active entity, or you can continue sketching.

    If you continue sketching, the active entity is automatically finished, as seen in the images below.

      

  3. After updating the Data Entry parameters, to finish the active entity, you can either click OK or you can click the next arc center.



  4. Repeat this process of using sketching and data entry to create arcs as needed.

  5. To close the function, click Cancel.

Multi-Picking

  1. Open the function and select the Multi-picking option in the Center Selection Mode group.

    The Selected Geometry list appears.

  2. Select the points in the graphics area to set as the arc centers.

    The arcs appear on the points, and are now active entities.

         

  3. Update the Data Entry parameters to modify the active entities.

  4. After updating the Data Entry parameters, to finalize the active entities, click OK.



  5. Continue this process to create the needed points.

  6. To close the function, click Cancel.

Example

  1. In the Quick Access Toolbar, click New.

  2. In the Entity group, of the Create 2D ribbon, click the down arrow under Arc, and select Arc Center.

    The preview appears showing an arc at the default radius.

  3. Update the Radius to 0.5000.



  4. Update the value for Center X value to 0.2500.



  5. Update the value for CenterY to 0.2500.



  6. Update the End Angle to 90.0000.



    Notice the arcs produced by BobCAD-CAM move from the Start angle, counter clockwise to the End Angle.

  7. In the Data Entry Manager, click the Other Half button.



    Notice the Start Angle and End Angle do not change, but the preview of the result does.

  8. Click OK to finalize the arc.



    The preview reverts to the original Start and End Angles.

  9. Click Cancel to exit the function.

Related Topics

The CAD Overview