Both upper thread and lower thread are required in sewing. Before sewing, you need to insert the bobbin. The forms of bobbin case and way of bobbin insertion may vary among different machine models, please refer to the manual of the specific model for further details. The general steps are shown as follows:
1 Switch off the machine before inserting/removing the bobbin. Position the needle to the highest level by turning the handwheel towards yourself.
2 When placing the bobbin, the tip of the thread should be pulled out anti-clockwise and facing you.
3 Insert the bobbin in the case by passing the thread side slot as illustrated.
4 Leave a part of the thread outside the bobbin case and close the case.