I quilt on a vintage longarm. I have had to remove a whole quilt before. My daughter loaded it and the backing was almost a foot short. We were amazed that that could happen. We KNOW how to measure, or do we??? Of course, we had quilted too close to the bottom on the backing. She was rolling and I wasn't watching what she was doing. It was a bed size quilt and had to come off to add more backing. I was quilting with a panto.
We marked with a pin where the quilt top started on the frame, unpinned the whole quilt, attached the extra backing, ironed the new seam open and then reloaded. It really wasn't a big deal. It was easier because part (most) of the quilt was very stabilized by the quilting. I float my top and batting, so we pinned the backing back on the frame. Rolled all three layers twice to get it even, lined the pantograph back up and finished in no time at all. Looking back, I was glad something like that happened while my daughter was here. It made it a lot easier that there was two of us reloading, but I could have done it by myself. So, the moral here is....unload if you need to and reload. It's not that big of a deal.
Side note: After having to reload a quilt because of the backing shortage, I have not hesitated to take a quilt off the frame and reload sideways when I want to quilt a long outside border without having to roll several times. "smile" When I do that, I only load the part I need to have pinned to be stabilized for quilting. The quilt is only pinned to the leaders, none of it is on the rollers. The excess part of the quilt just hangs over the edge. When I figured that out, it saved a lot of time.
Last edited by Barb in Louisiana; 09-13-2018 at 07:16 AM.