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I don't know how to read whatever you wrote.
Q3D might not be displaying your object if you are only exporting one of them, if your normals are flipped, or you didn't include them in the .obj file, or if you're trying to export multiple separated objects as unique parts of the model. Play with your exporter settings and try to understand what each setting does and how it affects the exported file. As a general practice if your model is made of multiple parts its a good idea to fuse the pieces before you export with select+ctrl-J, and export different pieces as separate blocks.