AutoCAD link and precision

[alopez]

I'm creating a master site plan with a base CAD file linked in. I have a known point in the CAD file which I know the coordinates of. My revit base point should be right on top of that know point but when I zoom into that point the position of the lines change in relation to the revit base point. It is a minute diference but as I zoom in my base point is no longer on top of the known point.

[BIMgirl · Accepted solution]

This happens when you exceed the 20 miles radius which Revit supports. To ensure accuracy of the model, all model geometry must be less than 20 miles away from the startup location of the project base point. Often it happens that AutoCAD drawings are very far away from the 0 point (or if they are not, it can happen that there are some lines or points floating out in the space). 

The easiest way to solve this is to draw a window around the drawing, copy everything, and paste it into a new AutoCAD file using the 0,0,0 coordinates. 

Check this too: http://help.autodesk.com/view/RVT/2014/ENU/?guid=GUID-AFCA59C6-9E00-4576-BCA0-63EB3342B68C

Cheers, Lejla