slow performance after imported AutoCAD drawing into Inventor 2013 sketch

[theyser]

Abstract:

Inventor 2013 slows down a lot after I imported an AutoCAD dwg into a part sketch.  Even after I "cleaned" up the dwg, putting small sections on separate layers and imported each layer into separate parts with a single 2D sketch in each, with a single part visible, Inventor assembly view slows down a lot.

The long version:

I started with a 2D AutoCAD drawing (.dwg, created in AutoCAD Mechanical 2008) of a factory layout.  I tried to import the dwg into Inventor Professional 2013 as a part sketch.  The goal is to use the sketch to help constrain the 3D inventor assemblies (equipment items, machines, etc).

The factory layout is a 2D top view of the factory with all the machines, equipment items, paths, etc; it covers a large area 100+ m by 50+ m.  I tried importing the entire dwg as it is into Inventor via the ACAD button.  I left all the layers visible.  After 15 minutes, the drawing still was done importing.  I gave up and quit Inventor.

I tried again with a small section of the factory layout, maybe 5 m by 20 m, it imported fine, but Inventor performance took a nose dive when the drawing is visible.

I tried yet again, this time I put different elements on separate layers, e.g. one machine per layer.  I imported each layer into a 2D sketch for a part; with each part containing only one machine.  There is still a noticeable "lag", but I was able to constrain a 3D model of a machine to the part with the 2D sketch.  When the 3D model is constrain, I turned off the visibility of the 2D sketch part, performance went back to normal.

The question:

What options should I set when importing the AutoCAD drawing into Inventor 2D sketch?

How can I improve the performance?  It's only an issue when I have the 2D sketch part visible.  And even though I only need it to be visible to constrain the 3D assemblies, it's still very annoying.

[blair]

Create your new part, import into the sketch only the items required to locate the factory items. Try to have only base shapes for the factory items (rectangle or squares). Fully constrain the sketch with the auto-dimension. 

If the shapes that locate the factory items are on a single layer, only bring in that layer.

[JDMather]

I don't use AutoCAD much anymore so my memory on this is not so good, but  -

I think the problem is with geometry constraints.
If you can get the ACAD stuff as a block into Inventor as an Inventor Sketch Block so that Inventor can ignore geometry constraints I think performance will greatly improve.

I would be willing to run some tests if you could attach the dwg here.

I answered this same question here a year or two ago with a possible workflow, but I have no idea what I terms I would search on to find the thread.  I guess AutoCAD, sketch blocks ......possibly circuit board.... 

http://forums.autodesk.com/t5/Autodesk-Inventor/Copying-complex-AutoCAD-geometry-into-Inventor/td-p/...

After a bit of searching I think this might have been a discussion I continued off-line as there was some proprietary data involved.  Experiment with blocks/sketch blocks and no constraints.  Post your dwg file if you can't find a solution.