I picked up this machine about a month ago. Got it cleaned and oiled. Threaded it and started practicing on vinyl. Got tired of practicing and decided to actually sew something. Made a cover for the machine. Couple days later, tried to sew again and no way. Thread keeps jamming. It will actually pull the top thread, that I'm holding, into the machine and jam. Popped the safety clutch once. Set the hook timing. Same thing. I've had it apart, those 3 little screws, about 8 times. It just keeps pulling thread in and jamming.. Nothing was changed since I made the cover, it just quit....Any ideas?