The tightness of the film on the take-up spool is in effected by the drag from the feed spool and the film pressure plate, the take-up spool spring is simply to try to prevent it unwinding as the film leader clears the film gate. I only have the problem when I use Fomapan film which is the springiest film I have ever used and does tend to loosen on the spool when the leader clears the gate, the method I noted in my first post #1 works for me although I did forget to say that I open the back and gently rest my thumb on the spool as I do the extra winding-on to tighten it. Warning, it is not safe to try to pack out the spring as it can cause the film to jam as the spool diameter builds up.