Sublayer advantage and some more

The motor , plank , and sublayer plank 1.3 are all on one layer , then nailed to a second layer plank . Maybe I'm way behind here , and you all get this before me. :)

The above is woodnut's description of his origial level (the stuff on the left) I've done some other little experiments on the back of this. Some interesting stuff! Its probably best to open in sandbox to get a better view of all the motor connections.
At the bottom is a layer one cylinder and a layer one "sublayer? motor", but they won't connect. Also a layer one motor and layer one sublayer motor superimposed on each other. I think this may be a bug?