Hope I don't get in trouble for cross-posting but thought I might have more luck in here. I have seen quite a few different motorized trains and trolleys on here. I would love to build one for 2015 but am having a hard time understanding how exactly you use the motor up to drive the wheels. Could somebody walk me through this? I find that I do better with a cookbook method instead of pictures so I am just not quite getting it. Also, the majority of them seem to have two sets of wheels- a regular set of wheels for on the track and then a set of casters that ride inside the rails, how does this work? Thanks for any and all assistance.