I can't read so many comments suggesting a mother just be grateful for an underwhelming, piddling bit of child support without offering an example of what a good dad looks like, in my ex.
My ex has a severe mental health condition, so on paper/according to prejudice and stereotypes might look like a poor choice of mate. He is my ex because I did find it difficult to be his carer as well as a new mother and we argued a lot.
Now we're separated and co-parenting we get on much better.
He's not expected to pay maintenance because he's on disability benefits. He gives me £15 a week towards expenses nevertheless. He also pays, when and what he can, towards clothes, toys, school stuff, music lessons, sports/activities, haircuts, you name it. He's unable to travel, so I take DC on holidays and day trips...ex gives DC spending money for these and sometimes (if I need it) pays towards train fares, plus towards accommodation for holidays.
He looks after DC one evening a week when I'm working late and, depending on his health, two out of three weekends.
We have to be flexible, because his illness fluctuates, but we work round each other's situations to do what's best for DC.
If one of us is short of money the other pays extra (e.g. when ex's p.i.p. application got mixed up, I paid for things while helping him find an advocate etc.).
I think this is what we should be expecting as a basic, given standard from all exes (obviously depending on what they can afford).
It's ridiculous that so many men who don't have the difficulties and disadvantages my ex has in life refuse to care for their children. They should be ashamed of themselves.