Groups of objects

I'm trying to upload a model that consists of 20 objects grouped together - they intersect with each other, though not within themselves. However, when I upload the model, only one of the objects seems to get through.

The objects are grouped in Blender.

Hi Phil;

You need to Join the Objects together, not group them. Grouping only creates a logical association of Objects so you can manipulate them together. But they are still individual Objects. To join the together you select everthing you want to print and then hit {CTRL+J}. Even if the Objects are intended to be separate after they are printed, you need to do this in order for them to be a singular Model. Give that a go and let me know how it works.

Yes that worked. Thanks for the help, I feel silly for asking about such basic stuff but I couldn't find anything using the forum search.

I'd wager Albert Einstein has to ask a question or two in his lifetime... Nothing to feel silly about at all.