Insert a coin into the slotted screw on the top of the machine, directly above the presser foot. Turn the coin clockwise to increase the presser foot pressure for heavier fabrics. Turn the coin counter-clockwise to decrease the presser foot pressure for lighter fabrics.
Turn the numbered dial on the top of the machine clockwise to decrease the sewing machine's tension or counter-clockwise to increase the tension. If the machine is making large messy loops, increase the tension. If the machine is failing to complete the stitches, decrease the tension. In general, the proper setting will be between the numbers 3 and 5 on the dial.
Pull the removable sewing table at the base of the unit away from the rest of the machine, parallel to the machine's arm. Flip the hinged bobbin door at the base of the needle plate down and away from the machine. Pull the bobbin case out of the machine.
Hold the thread that emerges from the bobbin case and bounce the bobbin case lightly up and down. The bobbin should release about an inch of thread. If it unwinds by more than an inch, turn the adjustment screw beneath the thread hole clockwise and test again. If it unwinds too little, turn the adjustment screw counter-clockwise and test again.
Reinstall the bobbin case, close the bobbin door and slide the sewing table back into place.
Turn the stitch length dial on the front panel of the machine clockwise to create larger stitches with the machine or counter-clockwise to create smaller stitches. In general, larger stitches are used in heavier fabrics while smaller stitches are used in lighter-weight fabrics.