XL-3500/ t/ i/3510/3520 FAQs & Troubleshooting XL-3500/ t/ i/3510/3520 Not your product? Upper Threading How-to information about upper threading. Bobbin (Winding/Installing) How-to information about winding or installing bobbin. Presser foot How-to information about presser feet. Needle/Thread/Fabric How-to information about needle, thread and fabric. FAQs & Troubleshooting
