I am at a complete lose here. I change my steppers from 1.8 to 0.9 and replaced the pulley with a 16 tooth. I am trying to get the wheels tighten back to the rail. No matter how I do it there is always play. I must have tried it 30 times and I can never get them tight again. They were perfect. I had no banding issues at all. I also replaced the belt to be sure I was good there. Is there some special way I am missing.