Why is my Bernina 930 Record is squealing?

SOURCE: My bobbin cotton wraps around the bobbin holder and jams the machine

I know this is probably not the answer but: are you sure the thread is coming off of the bobbin on the left side (bobbin in machine correctly), and when I first got my machine I tied to use the bobbins that I had on hand that fit my Singer machine. I had tons of problems with the "odd" bobbins that did not fit correctly into my machine. There is a VERY small size difference, but it does make a difference.

joanne

SOURCE: Bernina 930 where to put oil

There are two key points I suggest customers can do themselves to help lengthen the life of their machine. One is your hook and the other is the needle bar...
Hook - Open your bobbin door, removee the bobbin case/bobbin. On the upper left corner there is a small latch, push in the latch and your shuttle race ring will fall down forward. You can now remove your stainless steel hook. You need to keep this hook clean and the lip it fits back into clean and void of lint and debris. On the back of this hook or the "lip" that the hook fits back into apply a small amount of hook/sewing machine oil.
Needle Bar - Open up your head cover, the needle and needle bar clamp is attached to a long stainless steel rod that travels vertically inside your head. All sewing machines have a needle bar that looks like this. This bar travels thru two brackets attached to the frame of the machine. Rotate your handwheel and clean the needle bar well of debris. Rotate the handwheel so that the needlebar is in it's highest point and apply a small amount of oil to the upper and lower bracket of the frame, rotate the handwheel so the needlebar slides back down and therefore lubricating it and the inside of the brackets.
Hook oil or sewing machine oil is relatively inexpensive from all quilt, sewing machine, repair shops.

Be sure to take your machine in a minimum of every three years for proper cleaning and lubricating of all the other parts (This is of course for average home sewing machine use 8hours a week)

SOURCE: Upper thread knots up with bobbin thread when sewing a stich

Thread test
Test your thread quality to start, thread your machine and LIFT the presser foot (this opens the tension disks). Pull your top thread straight back. If you feel no tension no mater how much thread you pull, your thread is good. If that your machine passes that test, then let me know, we can go to step 2. If not, try different spool of thread, same test until you get a smooth pull (tip: always check your thread this way when you thread your machine)
Step 2:
Pull on your threaded bobbin thread while it’s in the machine. Does it pull smooth and even? If so, go to step 3. If not, try a new bobbin (bobbins get bent or distorted if wound too tight).
Clean thoroughly in the hook and bobbin case area and oil 1-2 drop is all.
Thread knotting on the bobbin can be a lot of things but here's some guidance:
Tension:
If the thread is loose on the bottom of the fabric, it's actually the top thread is too loose. Think of 2 little elves playing tug of war in your machine, one on toip and one underneath. If you have loops on bottom, the top needs to pull harder (tighten top tension)
Jamming bobbin case:
If it is damaged from turning out of place once, it could have rough spots on it that makes the thread hang on it, and keeps making it turn over and over. Use a finger nail board (fine sanding) and smoothall rough spots. Then reset the bobbin case taking care to put the notch in the bobbin case in alignment with the proper spot in the machine (basically 5 o’clock) when looking at the round area where the bobbin case goes.

Kelley Buchanan

• 130 Answers
• Posted on Apr 30, 2009

SOURCE: user manual download bernina activa 140 sewing machine

Try this... www.2instructions.com

SOURCE: Bernina 180 Artista sewing machine

you may have to replace the upper thread sensor