Great machine when it sews out most of the time. Always had that same problem..had to take bobbin out and turn the wheel to make sure no thread was caught in the bobbin case. Has done this since the day I purchased it. Brought it back several time to the place I purchased it and was always told it was fine..I have it at another place when I told him what it was doing he said he knew exactly what the problem was and he could fix it. so I will see. Good Luck