3ds Max won't export to .stl

[leonardi]

I have created an large 3D architectural model in ADT with over 2300 mass elements and AEC objects. I have made the model this way because changing the clients wall, window, and door placement is very easy.
I have been told the best way to create an STL file for stereolithography would be to use 3ds Max to do an STL check and then under the "Files" menu select "Export..." and then select the "Save as Type" as a stereolithography (*.stl) file. The problem is I don't get a choice for an STL file.

1) What could I be doing wrong in 3ds Max for it not to give me the .stl file choice?
2) Is there an application that will convert an ADT.dwg or 3ds Max.max file to a .stl file?

Thanks for your help

[Steve_Bennett]

You can run the command right inside ADT called STLOUT to create an stl file.

Also, make sure you are importing, not linking the data from ADT to MAX to try an export.

[leonardi]

Steve, thanks for the response.

1) I can't use the ADT STLOUT command because it requires that all objects be 3D solids which kind of negates the reason for useing ADT.

2) I did however get 3ds Max to convert the ADT file to an STL file by "importing" the ADT.dwg file into 3ds Max and then "exporting" it as an STL file.

Thanks Again