Don't they include Inventor with the kits?
I've found that, for actual modeling of the 'bot, it beats AutoCAD. And yes, I should know. I've spent the past three years learning CAD (4.5 credits' worth). Let me just say this: Constraints.
As for animation, Inventor will (if you're very desperate) do rudimentary animations. However, unless you have absolutely no alternative, DON'T TRY IT! There is no speed control: all motions/tweak groups happen in a set period of time. You can only use rotational and linear motions. All points/axes of reference must be on the parts, and some of them are not what you'd expect. It's a pain in the rear to get anything as complex as my Gimpy Stick Figure to move. I would put up a clip, but it's too big.
