@Katesboy8
I understand your frustration, and please let me reassure you, that the issues with sleeping overnight will get better.
However, it's a totally unreasonable expectation that your childminder will be able to facilitate your DC's nap to the same extent that you can at home.
E.g She's got 4 kids to look after, of various ages and stages of development, therefore it wouldn't be appropriate for her to get them all fed and napped at the same time simply because of their various ages, never mind the individual parents desires and routines.
It would, however, be reasonable to expect some kind of routine at the childminders, but not the same one you have at home ?
Does that make sense ?
Your DC can easily get used to another 'routine' at the childminder. In fact, he's going to have to get used to a different 'routine' again at nursery, and yet another at school.
I get that you'd rather stick to the routine you have at home, where you have only your DC to accommodate, but the harsh reality is that that simply won't be possible anywhere else like a childminder or nursery.
Children grow and adapt to lots of different routines throughout life, they have to, and while it's obviously very frustrating and unhelpful when you're struggling to get him settled at night, please take some small comfort from knowing that you are doing everything possible to ensure he is happy, healthy and loved (and it will pass, I promise you !), and that as long as he is happy at the childminders, you're doing great.