Thank you Michael for you very detailed explanation.By the way it shows me joined surfaces.Now I see where is the problem.Ok I will check where are gaps in my 3d models.I don't have 3d printer and I don't know a lot how to prepare my 3d models,now I see how it works.
By the way here are links for my printable 3d models created with moi3d V3 version, where others can download my 3d models and 3d print if they like it.Members can tip me,but for now nobody gave me a TIP.Anyway it's fun for me to see how my 3d models created with moi3d look as real objects.I hope so you will like it.