How to import openscad model in autodesk inventor

I drew something in openscad and wanted to send it to my collaborators who use autodesk inventor (2013). I naively thought it would be easy, but it turned out to be a little weird. Inventor 2013 opens STL files, but it always adds or subtracts random things to the files I tried, so first you have to fix it up (using Inventor Fusion 2013).

Here's how I got it to work (I didn't figure any of this out, google told me):

1. In openscad, export as .STL
2. Open the .STL file in Inventor Fusion 2013. It should look correct.
3. In Fusion, save as a .STL file
4. Install the Inventor addin Mesh Enabler
5. Open the .STL file (the new one from Fusion) in Inventor. It should look correct. Instead of drag and drop, I open from Inventor so I can set my units under 'options'.
6. Right click on the part and select 'Convert to Base Feature'. Select output 'Solid/Surface' (cube) and check 'Delete Original'. Wait a bit.
7. Now you can save as a .IPT file and you're done!