If all you want to do is animate your bot the Inventor Studio is a much easier route. There are a couple of tutorials on this in the Help.
I will be out of town for the next week. If you haven't found the answer to your Dynamic Simulation problem I will run through the tutorial again myself when I get back to try to identify the problem.
If you can get on
http://engineersrule.org (simply request a guest registration if your school isn't listed) there is different tutorial there on Dynamic Simulation that is easier to follow.