My ex husband and I have joint custody of our daughter. What is the possiblity of getting full custody of her?

Question Details: When my husband and I divorced 3 years ago, my daughter was three years old. We both lived in the same town and it was decided that we wanted joint custody. However, she is now almost 6 and going to be in kindergarten. He now lives in a town about 40 minutes away and doesn't believe that this will effect her schooling. I want to have a schedule where she is in one home during the school week and her schedule is constant. He however disagrees and wants her to go back and forth. It was his choice to move and I want what is best for my daughter. How would a judge see this? Important Notice