Needle arm stuck
Firstly, do you pull the fabric as it goes through the machine; this is a surefire way to break needles. Tension imbalance shouldn't be breaking a needle; more likely the thread would break if the top tension is too tight. And botton tension shouldn't need adjusting at all.
It may be that your needle is striking the presser foot if you are applying some "pull" to the fabric at the back of the foot.
But sewing very heavy fabrics is a challenge for many domestic machines - upholstery, heavy denim and canvas is tough going for many machines. Some tough mechanical machines will manage it but many won't. You can try using a roller or walking (even feed) foot as this may help with moving the fabric through but often the feed dogs just can't grip and move the heavy fabric enough. If you need to sew heavy fabrics regularly maybe consider finding a 2nd hand industrial straight stitch machine such as the Singer 20U.
In the case of your Bernettte, remove the needle plate (two screws), pressure foot, stub of needle and bobbin and then search the bobbin rotary hook area and see if there is a piece of needle stuck anywhere, you may need to turn the machine upside down and see if it falls out of the race area. I think this machine has a plastic horizontal bobbin case ??? If so, you will probably find that this has dislodged and may have been struck by the needle so remove it and give it a good visual check for damage, if there is a pierce mark, then give this a file down with an emery board to smoooth it. While it is out, see if the flywheel will now rotate the rotary hook fully.
Then reassemble by putting the bobbin case back in lining up the mark on the case with the stopper in the rotary hook, replacing the needle plate, pressure foot and a new needle.
If you can't get it to unlock at all, then it will need to go to a technician for repair.
Nov 07, 2011 |
Bernina Bernette 75