USER COORDINATE SYSTEM:


AutoCAD Command List

The USER COORDINATE SYSTEM allows you to reposition the XY plane for use with AutoCAD commands.


In many instances, AutoCAD uses the XY plane to orient the placement of certain types of items.

Example:
To place a cylinder through the RIGHT SIDE face of the model shown below, the XY plane must be aligned with the RIGHT side of a model. The UCS icon, seen in the illustrations, changes to match the new orientation of the XY plane.


Creating a UCS with Three Points:

--Prompt: Command: Type ucs and press Enter.

--Prompt: Origin/ZAxis/3point
/Entity/View/X/Y/Z/
Prev/Restore/Save
/Del/?<World>: Type in 3 and press Enter.

--Prompt: Origin point<0,0,0>: Use an Osnap or coordinate to select the position for a new 0,0,0 point (this selects the junction of the X, Y, and Z axes). NOTE: The intersection Osnap will NOT work with solid models.

--Prompt: Point on positive portion of the x-axis <0.00,0.00,0.00>: Use an Osnap or coordinate to select the direction of the desired X-axis. NOTE: The numbers inside the brackets< > will not necessarily be the same as those shown in this example.

--Prompt: Point on positive-y portion of the UCS XY plane <1.00,40.63,10.07>: Use an Osnap or coordinate to select the direction of the Y-axis. The UCS icon should change position to indicate the new UCS orientation.

Example:

The FIGURE BELOW illustrates the selections that could be made to create a UCS for the RIGHT SIDE using the 3 Point option.


Saving a UCS Configuration:

--Prompt: Command: Type ucs and Enter.

--Prompt: Origin/ZAxis/3point
/Entity/View/X/Y/Z/
Prev/Restore/Save
/Del/?<World>: Type s and Enter.

When the prompt asks for a name, type a name. The name can contain up to 31 characters. Press Enter to accept the name and exit the command.


Creating a UCS with the VIEW Option:

The View option sets the UCS to match the current viewpoint (Vpoint).

--Prompt: Command: Type ucs and Enter.

--Prompt: Origin/ZAxis/3point
/Entity/View/X/Y/Z/
Prev/Restore/Save
/Del/?<World>: Type v and Enter. The UCS will change to match the Vpoint.


X/Y/Z Options:

The X, Y and Z options allow you to rotate the UCS around an axis.

--Prompt: Command: Type ucs and Enter.

--Prompt: Origin/ZAxis/3point
/Entity/View/X/Y/Z/
Prev/Restore/Save
/Del/?<World>: Type the axis letter (X, Y, or Z) you wish to use for the rotation.

--Prompt reads: Rotation angle about X (axis indicated depends on selection) axis: Type in the number of degrees and the current UCS will be rotated about the selected axis this amount. The angle given can be positive or negative. Rotation around an axis is Positive in the counter-clockwise direction and Negative in the clockwise direction.

Examples:

If you started in the World UCS and rotated the UCS 90 degrees about the X-axis, the XY plane would be parallel with the FRONT view.

If you rotated a UCS that is parallel with a FRONT view 90 degrees about the Y-axis, the XY plane would be parallel with the RIGHT SIDE view.


Selecting a Saved UCS from the UCS Dialogue Box:

--Prompt: Command: Type dducs and press Enter.

When the UCS dialogue box appears, click on the name of the desired UCS, click on the Current button, and then on OK to exit the UCS dialogue box.

HELP Note: When you are using multiple User Coordinate Systems, check the UCS icon frequently. This icon changes with the UCS and helps you remember the orientation of the X, Y, and Z axes.


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