Tipster Danny Korem shares some tips for ensuring your AutoCAD files reference properly.

“Many times I get calls from CAD users who have difficulties while attaching files as xrefs. I have an automatic answer: 'Is the file to be attached in WCS (World Coordinate System)? Are the units set correctly?'

“To make sure insertion points don't get confused, both the current file and the subject file to be attached should be in WCS. This way, the insertion points (and base value of both files) can be shared. Other options are definitely problematic.

“As in the case of coordinates, units behave themselves only if the units are set and the file is saved according to those settings. The units factor will be automatically calculated while in the attachment procedure. Many people don't set units within their files, use the wrong template, or — worst of all — their file is unitless. That means the software won't be in charge and the user has to provide the units factor according to the units represented at a certain discipline drawing file.”

Notes from Cadalyst Tip Reviewer Brian Benton: AutoCAD will do a lot of the work for you — let it. After all, isn’t that why we use CAD programs? AutoCAD has an Insert Units setting (type Units on the Command line and change the settings appropriately). If this is set correctly in your file and in the file (or block) you are inserting or referencing, then the units for either file are irrelevant. AutoCAD will automatically scale the referenced file to the appropriate factor so that the real-world lengths of your drawing objects match up.