Note: There is a top and bottom to the shuttle. The slot screw goes in the big hole on the bottom and the decorative screw in the smaller hole on top.
Do not overfill bobbins.
There's a fine margin for tension adjustment on the screw. Generally, between 1/8" - 1/16" turn, but can be as slight as 1/32".
To remove bobbins, hold shuttle bottom side up in left hand between thumb and middle finger, with index finger on top screw. Turn slot screw counterclockwise.
Reassemble by inserting bobbin (make sure thread comes out correct side), insert top screw, turn shuttle over and hold same as removal. Insert bottom screw and gently turn counterclockwise until screw clicks, setting screw threads. Turn screw clockwise until snug. Turn shuttle over and pull thread to check/adjust tension.
When ready to pull thread from shuttle, hold shuttle point up with index finger on top screw and thumbnail in slot on bottom screw. Hold the screw stationary and turn the shuttle around the screw. Push tail of shuttle out with middle finger (loosens screw). When you have desired length of thread, reach out with middle finger and pull tail of shuttle back (tightening screw). Gently tug thread to feel if taut. Repeat middle finger motion is tension is loose. It may help to snug up tension by pulling a little extra thread while simultaneously conducting middle finger action.
Should the screw overtighten, back-twisting the bobbin will loosen the screw. Back-twisting is turning the bobbin in the opposite direction the bobbin turns when pulling thread from it.
The thread must come out of the shuttle on the rear right side in order to turn the screw in the correct direction when thread is being pulled from it.
