Thread snarled up under your seam?
Why Threading? Is threading the solution to your problem?
by Russell Moore
Threading mishaps are a problem encountered by novice and experienced operators alike. I
intermittently, misthread a machine and confront the same results as you will. I've been threading
multiple machines daily for nearly forty years and repairing them for as long. I have a standard
test for threading accuracy and implement it each time I thread a machine. It's a useful tool that
gives me confidence each time I start a seam. You're using a threading technique that been
working for time after time without any incident or mishap. Most operators learn the threading path sequence and thread the machine rather routinely without considering the components. Threading mishaps are a problem encountered by novice and experienced operators alike. I've threaded thousands of machines and intermittently I make a threading error that results in a thread lock or a gob of thread stuck in the needle hole. I thread many machines, a variety of brands and ages, daily and perform dozens of machine repairs each month. I have a standard threading test and implement it each time I thread a machine. It's a useful tool that gives me confidence each time I start a seam. You're using a threading technique that been working for time after time without any incident or mishap. Most operators learn the threading path sequence and thread the machine rather routinely without considering the components. It can be compared to flipping a lights switch to turn on the lights or turning the faucet handle to get water. You don't need to know how electricity is produced if you understand that flipping the switch gives you light. However, if it doesn't work? "If at first you don't succeed, try try again." This leads to frustration. That's why I am encouraging you to develop a foolproof technique. The best way to do this is to get acquainted with the thread handling components and the principles of how they work. You'll learn the sewing machine nomenclature so you'll be able to relate to my instructions.
Note: Review threading path. Begin with needle.
1. 15c bobbin case: If the bobbin case is inserted from the left side, the needle should be insert with the flat side to the right and the needle will thread from left to right.
2. If the bobbin case loads in the front, the needle is inserted with the flat side to the rear and the needle threads from front to back.
3. Another threading clue: The last thread guide, located at the needle clamping screw, will provide a clue as to what side the needle threads from. If the thread guide is on the right, you'll thread the needle from right to left. If on the left, you'll thread the needle left to right. On the front, thread the needle from front to back.
4. Thread the machine with the presser ft up, carefully pulling the thread between the tension disc. Lower the foot and thread the take up lever, the needle etc. Start the machine with the take up lever at the top.
5. The exception to the rule - The Singer 15-91: The hook is designed differently and passes the needle on the left side. The needle is installed with the flat side to the left and threads from right to left. (The last thread guide is also on the right.)
he threading path is a circuit that's designed to feed thread to the hook. The hook picks the thread from the needle and drags it around the bobbin case. The volume of thread needed for this trip around the bobbin case comes from the take up lever. At the end of the hook rotation, the hook is releasing the thread and the take up lever is pulling the excess thread tight to form the stitch. If the thread tension is not engaging the thread, the take up lever will pull additional excess thread from the spool, thus leaving excess thread under the seam that has not been recovered. The take up lever needs the tension to hold the thread tight while it's recovering the thread loop that's been dispersed to make the circuit around the hook. You can observe this process by opening the bobbin case cover while turning the hand wheel by hand. You will see the thread travel around the bobbin case and observe the relationship of the take up lever motion in this thread handling process.
An essential component of this process is the top tension assembly. The tension module has a spring pressing into the tension disc. The pressure on this spring is released when you lift the presser foot lifter lever. Lifting the foot releases the tension on the thread allowing the operator to pull the fabric freely from under the foot without breaking the thread at the eye of the needle. This mechanism is called the tension release linkage and is instrumental when threading. The thread is easily pulled into the tension with the presser foot up. The threading is difficult with the presser foot down unless the thread is pulled intentionally into the tension disc all the way to the tension post. I recommending you always thread the tension module with the presser foot up. You can test threading by lowering the foot and pulling it from the tension. The thread pulls hard when the foot is down, pulls easily with the presser foot up.
Rather than hauling the machine to the repair shop, let’s try to resolve the jam. If the fabric is jammed in the needle hole, you may need to cut it out. Removing the needle plate may be necessary if you want to save the fabric. In the case of a 15 Class hook system (one with the bobbin case you install into the hook through a little compartment door in front of the machine), you’ll want to remove the bobbin case, hook cover and hook. These pieces go back together like pieces of a puzzle and you’ll need to perform this operation when oiling your machine too.
With a top loading bobbin, first trim your threads, raise and remove the presser foot, remove the needle plate, and this should give you access for removing the fabric and removing any thread lock.
Most common thread lock can be eliminated by turning the handwheel backward. Try this first. Top loading plastic bobbin cases can be damaged by a thread lock. Resulting burrs and needle punctures will result in thread handling problems and infinite frustration. See your local dealer for a solution.