Thursday, 6 June 2013

SolidWork 2013 - Drawing And Modifying Spline

DRAWING SPLINES

CommandManager: Sketch > Spline
SolidWorks menus: Tools > Sketch Entities > Spline
Toolbar: Sketch > Spline

To draw a spline, choose the Spline tool from the Sketch CommandManager.
Then, using the left mouse button continuously, specify the points through which the spline will pass. This method of drawing splines
is similar to that of drawing continuous lines. After specifying all points of the spline, right-click to invoke the shortcut menu. If you need to exit the current spline and draw another spline, choose the End Spline option. Now, you can draw a new spline. If you need to exit the Spline tool, choose the Select option.

When you select a spline using the Select tool, handles are displayed on the points. These handles are used to edit a spline. You will learn more about these handles below .

Modifying a Spline

You can perform four types of modification on a spline.
The first is the modification of the coordinates of the selected control point.
The second modification is by using the Spline Handles.
The third type of modification is by using the Control polygons.
The fourth type of modification is the addition of a curvature control symbol.


Modifying a Spline by Using the Control Points

To modify the location of the control points of a spline, select the spline; the Spline PropertyManager will be displayed. The control points of the spline will be displayed with a square. The number of the current control point and its coordinates will also be displayed in the Parameters rollout of the Spline PropertyManager. When you set the value in the Spline Point Number spinner, the corresponding control point will be selected in the spline. Now, you can modify its coordinates using the X Coordinate and Y Coordinate spinners. Alternatively, you can select and drag a control point, to place it on the desired location.

You can also add more control points to a spline. To do so, choose Tools > Spline Tools > Insert Spline Point from the SolidWorks menus.
Alternatively, select the spline and right-click to invoke the shortcut menu. In this menu, choose the Insert Spline Point option.
Now, specify a location on the spline where you need to add the control point; a point and a spline handle will be displayed at the point specified on the spline. After adding the required number of control points, invoke the Select tool and select the spline again. You will notice that the boxes of control points are displayed on all points including the newly added points.

Modifying a Spline by Using the Spline Handles

A spline handle is a line with diamond handle, arrow, and circular handle on both its endpoints.
The spline handles will be displayed when you select a spline using the Select tool. The default spline handles will be displayed in gray, which implies that they are not selected. When you move the cursor over a spline handle, it will be highlighted in orange. Additionally, a rotate symbol will be displayed if you move the cursor near the diamond handle. A red colored arrow symbol will be displayed, if you move the cursor near the arrow. If you move the cursor near the circular handle, both the symbols will be displayed. Move the cursor near the diamond handle, arrows, or circular handle; it will be highlighted.

On selecting any of these entities, the number of respective control points and their coordinates will be displayed in the Parameters rollout.
Select and drag the diamond handle to dynamically modify the direction of the tangent. As you drag the diamond handle, the value in the Tangent Radial Direction spinner will change dynamically. When you drag the cursor the Tangent Driving check box is also selected automatically. After modifying the shape of the spline, click anywhere in the drawing area to exit the current selection set. You will notice that the currently modified spline handle is displayed in blue, which implies that the default setting of this spline handle is modified.
Select and drag the arrowhead to modify the tangent weighting. As you drag the arrowhead, the value in the Tangent Weighting spinner will change dynamically. If you press the ALT key while dragging the arrowhead, the spline will get deformed symmetrically.
Similarly, you can edit the spline using the circular handle. In this case, both the symbols will be displayed. So, the values in the Tangent Radial Direction and Tangent Weighting spinners will change dynamically.
Choose the Reset This Handle button to reset the current handle to the original position. Choose the Reset All Handles button to reset all handles to the default position.
To create a smooth curvature after editing the handles, choose the Relax Spline button.
To add more spline handles, select the spline and right-click to invoke the shortcut menu. Choose the Add Tangency Control option from the shortcut menu; a spline handle will be attached to the selected spline. Move the cursor to the location where you want to place the spline handle and click on that location. A spline control point will also be added along with the spline handle. You can also apply relations to the spline handles.

Modifying a Spline by Using the Control Polygon

To display the control polygon, select a spline and right-click; a shortcut menu will be displayed. Choose the Display Control Polygon option; the control polygons will be displayed. When you select a control polygon, the Spline Polygon PropertyManager will be displayed. You can also set the location of the control points by using the X Coordinate and Y Coordinate spinners in the Spline Polygon PropertyManager. You can modify the location of a control point by dragging it. To turn off the display of the control polygon, select a spline, invoke the shortcut menu, and choose Display Control Polygon again.

Adding the Curvature Control

You can also add a curvature control symbol that is used to modify the curvature of a spline.

To add a curvature control, select a spline and invoke the shortcut menu. Choose the Add Curvature Control option from it; the curvature control symbol will be attached to the selected spline. Move the cursor to the location where you want to place the curvature control symbol and click; the curvature control will be added. Also a spline handle will be placed at the location where the curvature control symbol is attached tangent to the spline. Now, select and drag the dot symbol at the bottom of this curvature control symbol. You will notice that the curvature of the spline is modifi ed dynamically as you drag the cursor. After modifying the shape of the spline, release the left mouse button.


Converting a Sketched Entity into a Spline


To convert a sketched entity into a spline, create a sketched entity using normal sketching tools. Choose the Tools > Sketch Tools > Fit Spline option from the menu bar to invoke the Fit Spline PropertyManager. You can also invoke the Fit Spline PropertyManager using the Fit Spline button from the Sketch Tools toolbar added after customizes. Select the entities to be converted into a spline using the select tool. Specify the tolerance using the Tolerance spinner. As you specify the tolerance the value of actual deviation is displayed in the Actual Deviation display box below the Tolerance spinner. The preview of the spline created is displayed in the drawing area. If you select the Delete geometry check box then the original sketched entity will be deleted, otherwise the original sketch will be displayed as construction geometry. Choose OK from the Fit Spline PropertyManager or choose the OK icon from the confirmation corner. Now, select the newly created spline using the select tool and right-click to invoke the shortcut menu. Choose the Simplify Spline option from the shortcut menu to invoke the Simplify Spline dialog box. Choose OK from this dialog box to display all the control points of the newly created spline.

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