Exporting Model to CAD using co-ordinate system

Hello,

I have modeled a ground mounted solar array in Sketchup. The array is quite large - 2000 frames contained within two fields. I am trying to export this back to AutoCAD. When using AutoCAD (11) we draw here in our national grid system Irish Grid or in some cases ITM. This basically means if we draw a line 10 metres from one known co-ordinate, the resulting co-ordinate will be 10m away on the ground, pretty handy.
I have geo-located the model in Sketchup, however I cannot get my AutoCAD export from Sketchup to line up correctly. Her’es what I do, I go to plan view of the panels and zoom extents. I pick two points where there is intersecting ditches as far apart as possible and draw two circles in Sketchup. I export the panels and two circles back and use the circles to align the panels in CAD. However the panels never fit as they do on Sketchup and will be crossing field boundaries in some places. The other way I attempted to do this was to convert the lat/long of the origin which was geolocated in SU and bring this as a circle into AutoCAD. Then I would draw two circles 500m north and east of the origin in SU and draw the same circles 500m away in AutoCAD and try to align them this way but again it wouldn’t produce something accurate enough for me.

Can anyone help me?

The most usual reason for dimensions to be off in DWG exports is that you are exporting a 2D DWG with your camera set to Perspective. For an export to scale you must either export the 3D model or set your camera to use a standard view and set it to Parallel Projection.

Anssi