Quilting with a longarm machine makes the work easier than on a regular sewing machine due to the speed with which the quilter stitches together multiple quilting squares along one continuous row. Due to the speed and amount of work done in one running of the machine, it is not always easy to keep an eye on where the needle lands in the stitch or how much lint and debris collect in the bobbin case. These factors can cause the timing of the hook to get off course.
Remove the bobbin and bobbin case from the longarm machine by pulling on the shuttle lock, the lever on the front of the shuttle. The bobbin case is found inside the front end of the long arm. There is no cover over the bobbin assembly.
Remove the throat plate from the long arm by pulling down on the top to release the latch. The throat plate opens in the front right of the machine.
Turn the thumb wheel, in the back of the machine, to the right, to put the needle into the lowest position. The eye of the needle should be visible when looking through the bobbin assembly. You should only see half of the eye; if you do not, adjust the setting of the needle by unscrewing the needle handle and adjusting the needle. Tighten the handle once you can see the bottom half of the needle through the bobbin assembly.
Check that the five — or two, depending upon the machine — marks on the hook are lined up with the eye of the needle.
Loosen the three screws in the back of the bobbin assembly with the screwdriver that came in the machine's tool kit.
Adjust the hook to the position where the marks are aligned with the eye of the needle. Tighten the screws to keep the hook in its correct spot.
Return the throat plate back to its upright position and return the bobbin to the bobbin case.
Test the timing of the hook and needle by turning the thumb wheel through one rotation. If the needle glides through the hook in the middle without touching the hook, then the adjustment was done well. If it touches the hook or the marks are not lined up with the eye of the needle, adjust the hook again.
Turn the thumb wheel slowly in case the needle is not aligned.
Always unplug the machine from the wall outlet when working around the needle to prevent accidental injury.