Yeah... I know how to model certain objects, but making a complicated ride (we're supposed to show the gears working!) has just sent me into a panic.

We have been taught with video tutorials - one of them did cover simple expressions (to make some train wheels move) but I was off the week they covered it in class and just got completely lost when I tried to follow it. Doesn't help when the tutor spends half the tutorial going 'now, where was that menu/option again?' and looking for it!

I've modelled the octopus for the middle of the ride, and could probably do all the other 'parts' but I'm not sure how to join/group them together. Do they need to be physically joined (through edges, vertexes etc) or just grouped for the whole thing to move together?