One important thing to remember when attaching a gaucho bed to an RV is that most motion in a vehicle is going to be forward and backwards.
That means you have to have a hand crank that can handle these motions if you want your bed to roll out easily without making noise.
If you’re using aluminium this will add even more weight, so make sure the crank mechanism has enough power to roll it out when needed or opt for a lighter model instead.