Linked CAD keeps rotating

[russ.green]

I'm having a real issue with Revit that I can't get my head around or find documentation on.

I have a model setup and linked a DWG file. The DWG is a topo survey drawn in real co-ordinates.  The DWG is linked center to center then then I moved and rotated it to suit the orientation of my new building in Project North. See image 01.

I've then aquaired the co-ordinates from the DWG.

I've change to True North and rotated the view. See image 02

All seems to be OK. If I detach and re-attach this DWG using the shared co-ordinated it ends up in the correct place so I've started work on my model. 

However, I've noticed that when I close and re-open my model or force ther DWG to reload it shifts position and rotates so I have to detach and reattach. See image 03

What have I done wrong?

TIA

Russ

[Anonymous]

Well you could just open the dwg in a dwg viewer and use

that as a reference and build the topo in Revit.

If you think that might take a little more time than having

the dwg come into Revit and make everything happen

quickly, you'll probably lose even more time trying to do

it that way.

But it's true if you import those site plans on a regular

basis and really know how to handle an import, it is faster.

Probably be a good idea to get used to doing it both ways.

You could be a Revit site plan specialist.

[russ.green]

Thanks...looks like it was an issue with rotating my DWG.

I found this fantastic blog post! http://autodesk-revit.blogspot.co.uk/2007/09/shared-coordinates-true-north-project.html

[Anonymous]

Yeah in that blog they say it's easy to forget. 

Only a few months ago I posted a step-by-step

process for aligning DWG coodinates with

Revit coordinates, and I think I forgot it already.

And this is part of something strange about Revit.

I've been learning Revit for 7 years, and I keep

starting over with things I forgot because there is

so much. 

Maybe someone with a really good memory would

do better.

But also like they say in that blog, it really only 

happens with processes you don't do often.