My machine will not sew if the bobbin thread isn't in right. Learned that lesson right off. I took a picture of the needle as I took it out and as I put it in. The flat end is on the right. I've rethreaded it countless times. I did notice that the side screw that holds the walking foot on keeps loosening. I make sure to retighten it at every start. I have no idea how to test out my walking foot. I've quilted 4 of them so far and this was the first time it's happened. I was getting chunky thread the last time I used the yellow, but not to this degree.
I've never had bad thread. Is that possible?