Hi everyone .
Seems to me that there is a typo on Abandonned Machinery on the Rock Hopper.
In that state of the ability, it can never go on, as the rock hopper is in it's own aura thus preventing it to ever be 4" away from any friendly model.
The ability probably meens "other friendly model", I suppose.
Except if I missed something in the rules...
And sorry for my poor english, it's early in the morning and I'm french...