I got the quest and found the robot way to cool to sell, however then I sent it to the castle it stopped 50 meter from the gate well outside the build zone.

Find no ways to move it.

On pc so can use console.

Build a bar. He will hang out by that

problem solved by itself then I was away from castle an second time

Might put an bar next to him

Now ask for a beer, when his inventory opens up, give him all your nuka kola quattrum. Wait a little then come back and grab them, you'll love the new stats.

That reminded me, whats up with the fish joke he tells? At some point in the game Codsworth tells me the same joke, was funny as hell random stuff.

What quest in that?

Trouble brewing. You get it at Goodneighbour.

He really does move to a bar you set up. He navigated up my ramp on top of Red Rocket and is hanging out right next to my bar. He gets all my Nuca Colas of any variety. They all benefit from the stat boost.

Bar, as in decoration bar or as in shop?

Bar as in shop. He is standing right at one end of it.