>They still need to be fed though, energy, iron, etc.

But just like humans can help each other, robots could help each other too. This includes digging up various resources, finding means of power generation etc..

Otherwise you could say that humans are working for free as well, as they can cultivate their own food and even build themselves by making babies.

Of course, but none of them is working for free, each consume energy and materials.

By free, I mean "free of human effort"

If you own a factory, what you see is a big box with input and output, human labor is just an annoying variable, removing it won't turn the entire thing "free".

The owner will still expect to trade the output for something else for his benefit.

I am thinking of a case where governments will own the robots. People will pay some minimal tax to pay for the maintenance of the robots. If other robots can be made to do it, then even that cost is saved.

Government will, among other things, oversee that the needs of the people are well served by these robots.

If you think about it states are not much different than corporations.

Taxes is human labor dedicated to the maintenance of state.

I think it is naive to think that once humans are not needed they will magically be fed by the machines.

>If you think about it states are not much different than corporations.

At least democracies have elections and that is a big difference.

Energy has become nearly free, though, as the space- and cost-efficiency of solar skyrockets. That's really not the problem here.