Hi Don, your squeeze bottle seems to be fine.

One thing I noticed though is that it is not completely closed solid, the very top part of it has an opening:




It could be possible that TurboCAD doesn't like that it is not a closed solid and decides to break it apart based on that.

Because that's a planar opening at the top, it's easy to close it - in MoI select the bottle body there and then run the Construct > Planar command, it will build a planar end cap through the opening to seal it off and make it a fully closed solid. That could then make TurboCAD like to keep it in one piece better.

Another potential issue that you may be running into is that some programs don't like to read curves out of a STEP file. So you might try just selecting that body piece after it is solidified, and then use the File > Export command in MoI to write the STEP file. The "Export" command will only write out the selected objects to the file instead of writing all objects, and you might see a difference if you don't put any separate curve objects into the STEP file.

I tested doing those 2 things (use Planar to cap the end off, and only export just the main body part to the file) to generate a STEP file and tested it with a few different programs (Rhino, Alibre, ViaCAD) and they kept it all connected together...

- Michael