I'd like to hear what the issue is as well. I have 2 XR-640's and I also get head strikes when the prints gets out to around 30'. This is on calendered vinyl. Just today, for example, I ran a job on unidirectional and by the time it was at 25' it started head striking. Same thing the other day on a similar length run. After 25-30' there's slack on one side, no matter how carefully it's aligned at the beginning. This occurs on both machines, although my 1 year old machine seems a little more forgiving than my less than a month old machine.
I'll take it up with the techs soon, but I'd love to hear what you find out.
I'll take it up with the techs soon, but I'd love to hear what you find out.