How to Use the Bobbin on a Singer 604 Sewing Machine
- 1). Unscrew the two halves of the bobbin reel and remove any leftover thread. The bobbin must be empty before winding new thread onto it. If you do not wish to remove the bobbin, execute step 2 and then pull the remainder of the thread until the bobbin is empty.
- 2). Press down on the reel wind button. The button is located on the bed of the machine. This button toggles the machine between winding the bobbin and sewing.
- 3). Press the pedal and thread will be wound onto the bobbin. Continue pressing the pedal until the bobbin is full.
- 4). Push the reel wind button to the left and it will pop back up into the sewing position.
- 5). Turn the hand wheel to lower the needle and pick up the bobbin thread. Once raised, pull both the bobbin and needle thread towards the back of the machine and allow approximately 6-inches slack. You are now ready to sew.
Source...