OBJ export with correct material axis

Hi everyone, I’m hoping someone is able to tell me which box I’m not ticking. Apologies if this is the wrong thread as I’l be using the model eventually in Element 3D.

I have a car OBJ.
I’ve applied materials to all the individual bits I want to eventually animate. The problem comes with the wheels.
Each wheel has 9 different “bits” (sorry, new to Blender so don’t know the terminology).
Ideally, I’d be able to put all the wheel parts on the same axis as a group, export as OBJ, and hey presto an easy to manipulate wheel that rotates and turns on it’s own axis where I can then apply materials to those 9 parts as I see fit.
I’ve tried A>A to select everything and then SHIFT CTRL ALT C and set the origin to center of the mass, which moves the axis on all the bits away from one central car axis which is a bit of progress. Importing the car back in to Blender though and I’m back to having that one car axis rather than all the individual bits.

Is anyone able to help tell me what I need to do to make the wheel a group (if that’s what I even need to do) and have all the wheel bits share an axis that doesn’t get lost as soon as I export the OBJ.

Thanks everyone!

Not sure what a bit is, but if you mean a separate mesh part, then you can join them together. Spacebar join or control J. If that is not what you meant, post a part of the blend with the wheel at http://pasteall.org/blend/ and then post the URL so we can see it. Good idea in future to post a blend that way anyone can see what you are having trouble with.

Thanks, that was the answer!
By “bits” I meant meshes, yes. I just joined the meshes making up the wheel and Joined them. Setting the origin then exporting the OBJ means I’m good to go. Thanks for the help!

Unfortunately it wouldn’t have been fair on the artist who I bought the initial model from to post it up for people to get to; it’s his revenue stream and I didn’t want to damage that, so I hoped something in my screen grab would help :slight_smile: