A link to a supermatic manual is here
- I suggest you download this and print it out as this machine is over 50 years old now and manuals are scarce.
Disengage the clutch by holding the outside of the fly wheel and turning the inner knob of the wheel towards you.
You need to take the thread from the spool across to an eyelet on top left, then back to the bobbin winder, up through a hole in the top of the bobbin and hold the thread tail. Flick the bobbin across against the stopper. Now press the presser foot or knee control to start the motor. Hold the thread tail until youve got coverage across the bobbin enough to hold the start, then stop winding and cut the thread tail with scissors. Now continue winding but put the handle of your scissors on top of the thread spool to stop it bouncing and ensure your thread winds smoothly and under tension.
Watch the bobbin fill and give the thread a nudge to fill top and bottom as well as the middle evenly, you want a nice even wind. Fill to 3/4 and stop, flick bobbin back off the stopper, then cut the thread. Remember to re-engage the clutch by reversing the first step.
This is a lovely heirloom Elna machine - you need to thread the bobbin as the manual describes and get the thread into the tension spring. Please read the manual information on oiling too, this machine needs to be oiled on the red spot locations every time you use it according to the manual, use good quality clear sewing machine oil for this purpose.