If you don't let him see his kid, you don't deserve child support.
That's pretty much all I have to say. Now, granted, if he is a total piece of shit who is a dnager to the child, then stand your ground mama, and milk him dry.
But this is for those nasty ladies who refuse to let the dad see the kid just because he cheated, or pissed her off in some other way and the kid is the only ammo she has. I hate women like that.