Hi
This is about my dad. For context, I am mid twenties with a toddler.
Parents divorced when I was perhaps around 5, I'm not 100% sure. My dad was okay with us until I was around 11 years old, when suddenly it just all stopped. I remember waiting around for his calls and he'd say he'd visit and then never came. We had moved two hours away from him.
Ever since then, it's felt so forced. He doesn't talk to me (or sister) unless we start the conversation and he doesn't visit. I haven't seen him in many months and he doesn't speak to us anymore unless we reach out. My mother has always tried to keep him involved but he doesn't instigate anything.
I've forgiven him time and time again (with no apologies from him) for not being there but I'm just reaching my last nerve with it all. I gave him a chance again recently and reached out, however he engaged in a chat for a little while and then ignored me. No message in months.
I feel the ups and downs aren't worth it anymore. He's a good man and funny, everybody who meets him thinks he's great. He's been this way with his other children. I don't know 4 of my siblings because of him and his ways. He's been like this with all of us 
I'd hate to go NC and then something bad happen to him, but I also don't want this relationship any longer. I'm not sure at what point you decide which is healthier for you.