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Modifying the Suspension and Steering Subsystem

For a double-wishbone suspension, the line running from the lower spherical joint to the upper spherical joint defines the steering axis or kingpin axis. If these joints move outboard while the rest of the suspension geometry remains unchanged, the scrub radius is decreased.

In the suspension subsystem that you created, two hardpoint pairs define the locations of these joints:

•	hpl_lca_outer and hpr_lca_outer, where lca_outer means lower control arm outer, and the prefix hpl means hardpoint left and the prefix hpr means hardpoint right.

•	hpl_uca_outer and hpr_uca_outer, where uca_outer means upper control arm outer and the prefix hpl means hardpoint left and the prefix hpr means hardpoint right.

Hardpoints define independent locations in space.

To decrease the scrub radius, you modify the locations that these hardpoints define, as explained in the following sections:

•	Modifying Hardpoint Locations

•	Saving the Modified Subsystem

Modifying Hardpoint Locations

You must first display a table that contains data about the current locations that the hardpoints define. You can then modify the hardpoint locations. You only need to indicate how you want to move the left hardpoints in each pair, and Adams/Car modifies the right hardpoints accordingly.

To view hardpoint locations:

1.	From the View menu, select Subsystem.

The Display Subsystem dialog box appears, already containing the subsystem my_assembly.UAN_FRT_SUSP.

2.	Select OK.

3.	From the Adjust menu, point to Hardpoint, and then select Table.

The Hardpoint Modification Table appears. It displays the locations of all the hardpoints in the assembly. You can use this table to display and modify the locations of any of the hardpoints.

The locations of the paired hardpoints differ only by the sign of the Y location. Therefore, the paired hardpoints are symmetrical about the X-Z plane. With symmetrical hardpoints, you only need to move one of the hardpoints, not both. If you want, however, you can break the symmetry and move only one of the hardpoints of a symmetrical pair.

To see the symmetry, select left or right from the bottom of the Hardpoint Modification Table.

To modify the hardpoints:

1.	Click the cell common to hpl_lca_outer and loc_y.

2.	Change the existing value to -775. This moves the hardpoint point 25 mm outboard.

3.	Scroll the table window down until you see the hardpoint hpl_uca_outer.

4.	Click the cell common to hpl_uca_outer and loc_y.

5.	Change the existing value to -700. This moves the hardpoint 25 mm outboard.

6.	Select Apply.

Adams/Car changes the hardpoint locations of the two hardpoints and their symmetrical right pairs.

7.	Close the dialog box.

Saving the Modified Subsystem

In this section, you save the subsystem you just modified.

To save the subsystem:

1.	From the File menu, select Save.

Before saving the file, Adams/Car asks you if you want to create a backup copy of the file.

2.	Select No. This overwrites the subsystem file in your default writable database.

Adams/Car saves the subsystem file that you created.