Have a look at the assembly attached. I have put the track in the same .iam as the train parts, as per the pictures of the tutorials. I added the crank constraint relative to the wheel and then created the formula for the flush constraint to drive the train.
It would have been easier if the parts had been created properly, about the origin planes. So you will notice I have added a few extra work planes and re-constrained the train relative to the track.
The crank constraint has been renamed Drive Me, give it a go.
I have only done the first part but it should be enough for you to work out how to create a motion constraint as per the second part of the tutorial.
I hope it helps
Regards
Stewart
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Stew, AICP
Inventor Professional 2013, Autodesk Simulation Multiphysics 2013
Windows 7 x64 Core i7 32GB Ram FX2000