For Inventor, is it better to upload the assembly file only or should I upload the assembly's part files?
For Uploading in GrabCAD, you can use Google Chrome browser, and you can totally upload the folder of your project. Both IPT, IAM is mandatory and also it would be better if you upload a screenshot for the Assembly.
For getting more downloads, Please share the youtube link of your project animation.!
In Inventor its very important that you when you upload an assembly (iam.) file that you also upload all of the part (ipt.) files as well. The part files are a direct component to the assembly file. If you ever noticed the assembly file can be very small in comparison to the parts in them, maybe just 100 KB compared to several 1 MB part files. That's mainly because the assembly file just has the name/link of the part in it and the position that part is to go- it doesn't contain the actual drawing file. You can think of it as if the assembly file is a book cover and the part files are the chapters in that book.