Not agreeing with ex/ child custody/support

If the judge ruled custody and child support should be you having primary custody and pay child support then a notorized agreement, though may raise a good arguement with the court will probably not however get him off the hook from paying the child support. Depending on what the original order says, you may have to go back to court for this.
If I understand correctly, you still have primary custody and he is still supposed to be paying $600/month child support unless ordered differently by a judge. If he wants to take YOU to court to try to get primary custody of his children from you, it will be up to him to show why it would be a better situation for the children to be with him. If his only reason to try to get primary custody from you is not being able or wanting to pay child support, I would suggest that he NOT tell the judge that.
I applaud your efforts to keep him in your children’s lives and paying more than your share, but it’s time that he take his responsibility for that. If your court order says that you have primary custody, then you have primary custody and only another court order will change that. If your court order says he is to pay $600/month child support then he should be paying that and only another court order will change that. Let him insist on his way, legally it’s YOUR way that matters. If he wants to fight it, he can take you to court, pay the court costs, pay an attorney and more than likely still end up with the same situation you have now with the difference that he has to pay back child support for payments that he’s missed. Keep records of everything, e-mails, payments he’s made and what you’ve spent on travel and other expenses.
Good Luck

Another thought: If he wants to take you back to court and have the notorized agreement to hold up for him not paying child support while you are out of the country then the part about splitting travel costs 50/50 will have to be upheld also. He can’t have it both ways. He signed the agreement too and but has not held up his end of it by paying 1/2 the travel costs.
When you come back to NC in December, being as the notorized agreement is only good for the time you are away, then I would say the courts will probably fall back to the original order of you with primary custody and him paying $600/month.

I have been divorced for a little over 2 years now, legally separated for 3 1/2 years now. When we got divorced, the judge established the custody and child support to be the same as drawn up in our separation agreement. I have primary custody of the children, he was supposed to take them every other weekend, and pay $600 a month in child support for 3 kids, directly to me. He was the one who said he only wanted them every other weekend. Since that agreement, he wouldn’t show up when it was his weekend to take the kids. I would say he would get them one weekend every other month, his choice, not mine. He did not pay child support but for maybe 2 months, and I was working with him because he was drowning in debt and having hard time financially, so I thought. The truth was that he was out partying, spending his money on a new motorcycle and a 2nd car, while I was struggling as a single parent to raise the kids. I then got remarried. My husband is in the military. He came down on orders to come to Japan. I needed consent from the kids father to bring them here. He disagreed that I take them that far away from him. After pushing the fact that he failed to pay child support and never took them anyway, he agreed to let them go on his conditions. Which were, that he doesn’t pay child support at all while we’re here, that he gets the kids every summer and every other Christmas, and the travel expenses will be split 50/50. I agreed as I didn’t want to be separated from my husband. We drew up the agreement on paper, and had it notarized. The agreement is only good for the time that we are in Japan, and when we return a new agreement must be drawn up. Well, we’ve been here for a year and a half. I spent more than my half just so he could see the kids over the summer/ of course he was still struggling financially, and couldn’t afford to pay his half. He is remarried with a step daughter that lives with him, and he and his wife just had a new baby a few months ago. WE are due to return to North Carolina in December, back to the same city. I wrote him an email and told him he could keep the kids every other weekend, as with our regular agreement, and that should pay child support of $350 a month for our 3 kids. He wrote me back and said that he wanted to keep the kids full time, and that I could have them on the weekend. I found out from his mother that it was because he didn’t want to pay child support. I do not agree with the kids living with him for one because I’m the only one that has been there for them since they were born. Even when I was still married to my ex, he was never around. Secondly, they already have 2 kids living with them in a 2 bedroom house… 5 kids in a two bedroom house? I think not. 3rd, he can’t even afford to send the kids birthday/ Christmas gifts, or buy phone cards so he can call them, let alone afford to take care of 3 more kids full time. It is not logical to me. I emailed him and told him that I would agree for him to keep the kids once a week (Wednesday after school and all night) every other weekend, every other holliday, and half of the summer. $350 a month in child support. DO you think that is fair? If he keeps insisting on his way, should I take him to court? Would he even have a chance in hell in winning custody of them? My current husband and I don’t have any children together, its just my 3 kids. What is your advice?