Originally Posted by nursie76
All those suggestions are good. I found that my old machine would do that if the area around the bobbin case got full of lint. Try giving the machine a good cleaning, especially in that area. I usually found this after sewing on flannel. Good luck.
A good cleaning ... one of my friends had to tell me that it meant: taking the throat plate off, so that you are really seeing down behind your bobbin casing ... and the track of the feed dogs.
I took one of my machines in because it quit advancing the fabric ... long story short ... the next time it happened, I could hear my friend saying: CLEAN THE MACHINE!
I almost missed it, but between the feed dogs ... the lint from the fabric was stuffed in there so tightly it was actually FELTED! Take the bobbin and the bobbin case out if you can and also, after cleaning, are you oiling your machine? A drop of oil on your finger and rub it on to the place that the bobbin casing slips into ...
I don't know how accurate it is, but I use my thumbnail to check how firmly the bobbin is being wound. I have heard that if you do this process too quickly, the bobbin will not wind properly - - moderate speed was recommended.