I had the same issue and I called tech support and they had me take the left end cap of the machine off, there are two screws, one is right by the red strip on the front of the cutter and the other one is in the back. You will need to unscrew both of them and move the cap out of the way. Then, there is a gold screw that sticks out and I just had to turn it to put some tension on the belt to the blade holder. It fixed my problem.