question on nested xrefs

[mvrcad]

Gday all

work i slow today, so the boss has asked me to do some research into nested xrefs.

he wants to know if several drawings are xrefed into drawing, that is then xreffed into a presentation drawing... will the original drawings be "nested".

 

my thoughts imediately are that of course, thats what nested xrefs are. but i could be wrong.

 

is this a trick question?

 

cheers

 

 

also how do i prove this one way or the other? i have made some sample drawings that i am xreffing, is that the best way?

Edited January 20, 2012 by mvrcad
added the last bit

[mvrcad]

 

this seems to prove that the items are nested

Edited January 20, 2012 by mvrcad
removed company name from drawing

[mvrcad]

ok so now my boss wants me to find out what the negatives of nested xrefs are.

obviously its best practice to not nest xrefs due to file size, or making an overly complicated file structure.

but can anyone point out other reasons why its not best practice to nest xrefs, please.

[CyberAngel]

As you may know, there are two ways to attach an xref. An attachment (yes, it's confusing, all xrefs are attachments) is what we would consider a normal xref. An overlay applies only to the first inheritor, that is, if Drawing A is an overlay in Drawing B, and Drawing B is an xref in Drawing C, then A appears in B but not in C. So some drawings are nested and some are not.

 

According to the first site Google gave me, the benefits of xrefs are: individual drawings are smaller, multiple users can work on one project, users can stay current with each other, and the file hierarchy is flexible.

 

The downsides of xrefs? If you don't know what you're doing, or if your firm and your design team don't collaborate well, you can create a lot of chaos. If the various drawings aren't accessible to each other, you lose the benefit of staying current.

[tzframpton]

It just depends on your approach for plotting. Here's two scenarios:

 

 

• Scenario 1: Each "sheet" is a separate DWG file. If you have a ten sheet set of drawings, you'll have ten DWG files. Each sheet will have at least the Titleblock XREF, and any floorplan DWG as needed.
  
• Scenario 2: Each "sheet" is a separate Paperspace Layout Tab in one DWG file. Each Layout Tab will have a Titleblock, that is not XREF'd in, but an actual block. All floorplans, schedules, details, etc. will be inserted as an XREF into the one DWG file, which acts as a parent file, hosting all other XREF files.
  

Scenario 2 will require "nesting" of XREF files. Scenario 1, you can use nested XREF files, or not... depending on your situation.

 

 

 

Lets say, you need to create an electrical floorplan. You'll insert an architectural file as an XREF into a DWG file so you can overlay the electrical equipment and lights. If you use Scenario 2, you'll have to XREF the electrical DWG file into the master XREF file for plotting, which will bring in the architectural plan with it (if its inserted as an Attachment and not an Overlay). If you use Scenario 1, the electrical plan is the sheet, not requiring another XREF insert to any other drawing, which does nests the files continually.

 

 

 

You'll have to decide for yourself what works for you. I've worked for companies that do it both ways and there are benefits to both. If you do more than 5-6 sheets per job, I would highly recommend Scenario 1, or a third option which is using the Sheet Set Manager. If you use the SSM then XREF files are somewhat managed automatically.

 

 

 

Hope this helps some.