How to Detach Underlay in AutoCAD?

Detaching Underlays in AutoCAD: A Step-by-Step Guide

Understanding External References and Underlays

Underlays in AutoCAD serve as references that can be attached to your drawing files. They include various file formats such as PDFs, DWFs, and DGN files. These underlays are linked to your drawing but are not part of the drawing itself, allowing for a flexible design process. Detaching underlays may be necessary when they are no longer needed or when you want to replace them with updated files.

Detaching a PDF Underlay in AutoCAD

To remove a PDF underlay, follow these steps:

1. Access the External References Palette:

   • Navigate to the View tab on the main ribbon.
   • Click on the Palettes panel, then select External References.

2. Select the Underlay:

   • In the External Reference palette, locate and click on the PDF underlay you wish to detach.
3. Initiate the Detach Command:
   • Right-click on your selected underlay to open the context menu.
   • Choose Detach from the list of options that appears.

Detaching Xrefs: The Process

An Xref (external reference) can sometimes be mistaken for an underlay, but the detachment process is very similar. Here’s how to detach an Xref:

1. Open the Xref Manager:

   • Use the Xref Manager by typing XREF in the command line, or navigate to the View tab and find External References.

2. Highlight the Xref:

   • Find the Xref you’d like to detach in the list. Click on it to highlight.
3. Detach the Xref:
   • Right-click on the highlighted Xref and select Detach from the dropdown menu.

Issues with Detaching Underlays or Xrefs

Sometimes, you might face difficulties in detaching your underlays or Xrefs. Here are common reasons and their solutions:

• Nested Xrefs: If the Xref is nested within another Xref, it cannot be detached until the parent Xref is also detached.

• Locked Layers: If the Xref resides on a locked layer, it will prevent detachment. Unlock the layer first to proceed.

• Block Definition: If the Xref or underlay is defined within a block, it must be exploded, or the block must be modified before removing.

Removing Multiple References

Detaching multiple instances of an Xref or underlay can be cumbersome. Follow this procedure:

1. Select All Instances:

   • Use the QSELECT command to choose all instances of the Xref or underlay present in your drawing.

2. Delete Instances:

   • Once selected, delete them using the Delete key.
3. Detach Remaining Reference:
   • After all instances are deleted, proceed to detach the remaining reference as described in earlier steps.

FAQs

1. Why can’t I detach my Xref?
There are several reasons: it might be nested within another Xref, on a locked layer, or defined within a block. Check each of these possibilities to resolve the issue.

2. Can I modify a PDF underlay in AutoCAD?
No, PDF underlays cannot be modified or edited directly in AutoCAD. They are linked references, meant only for visual guidance during the design process.

3. How do I ensure my Xrefs are resolved?
To fix unresolved Xrefs, ensure the files are located in the correct folder, have proper permissions, and are accessible from the server you’re working on. Moving related files to the same directory can also help in resolving issues.