Mindful of the situation of some grandparents, enforced separations, I think seeing a grandchild once a week is pretty good. I don't think one can demand to see a gc whenever gps wish, parents have a life, sometimes very busy and it's not always convenient for them to have gps drop in or to visit. We are paternal grandparents, our son split with his partner a couple of years ago, he has his children every other week-end, Friday through to Sunday evenings and tends to bring them to us. I'm glad to have that regular contact, the childhood years are very special, I feel for those denied for whatever reason, they will never get that time back.
I really wouldn't push and make demands, I do perceive that's one, of a multitude of reasons, why some gps have found themselves in a "no contact" situation, it really is up to the parents to set the parameters and I think grandparents must always bear in mind they are one step back. Unfortunately it does seem that there are those grandmothers who want to make their gc their raison d'etre, but to be a grandparent, one must have been a parent first, and the reality is we've all had our turn in child rearing, so don't encroach but try and be a back up.