answer 1
Threading problems
If the thread gathers, loops or bunches underneath the fabric, there is a problem with the upper threading. If the thread gathers, loops or bunches above the fabric, the problem is with the bobbin (lower) thread.
1. Looping/nesting on the underside of the fabric.
This is usually caused by not threading the upper tension disks correctly. With the presser foot lever in the "up" position, and the tension set at 4, follow the threading guidelines at the top of the machine. Hold the spool of thread with your right hand. With the left hand, bring the thread down into the tension channel, around the bottom and up the other side. As the thread comes up the opposite channel, you will hear an audible click (current models only) as the spring engages, and the thread slips between the tension discs. Continue to thread the machine, but do not thread the needle.
Before threading the needle, perform this easy test to make sure the tension disks are threaded correctly. Making sure the presser foot is raised, pull the thread. It should pull easily. Now lower the presser foot, the thread should now resist when you pull it. There should be a significant increase in the tension of the thread. If there is no increased tension, the machine is not threaded correctly.
2. Looping on top of fabric.
This signifies that your bobbin is not inserted or threaded correctly.
Place bobbin in the case with thread winding off counter-clockwise. (The thread should pass over the top of the bobbin and drop off to the right). Slip thread through the notch located slightly to the left at the bottom of the bobbin case and pull it through the tension. Pull thread over top of throat plate and to the back of the machine. (See your instruction manual for details)
The bobbin tension is pre-set at the factory and usually never needs adjusting. However if the bobbin is threaded properly and the problem still persist, remove the bobbin case and adjust the screw on the side of the bobbin in small increments. Adjust as needed until loops disappear.
Loose threads or fibers caught in the tension discs and using the incorrect bobbins may also cause problems with sewing. Even though the plastic bobbins may look the same, they are not. The class 66 plastic bobbins are slightly beveled or rounded; the class 15 bobbins are flat and taller.
Always turn the handwheel TOWARDS you; to turn it in the opposite direction will knock the timing out.
A good suggestion is to use a contrast color thread in your bobbin for test purposes. This will help you recognize how your tension works.
Favorite Sewing Projects: Clothing Construction
Age of Current Machine: Less than 1 year
Sewing Frequency: Every day