Loose tension - Singer Sewing Machines

Thread breaking is normally caused by tension being too tight or by incorrect threading. If it is loose and jiggly, it isn't tight. Maybe your bobbin tension is too tight, and your top tension is far too loose.

video on threading and setup

https://www.google.com/search?q=Viking+topaz+40

Thread tension explained.

https://www.artisanstitch.co.uk/sewing-machine-tension/

..

The tension on the thread is too loose. However, first, verify that the thread is completely seated in the tension mechanism. When threading every thread on your machine, make sure the presser foot is always UP. When threading each thread, give each an extra little tug when going through the tension mechanism--sometimes you will hear the thread pop when it seats. A thread that is not seated will not have the correct tension applied, so the stitching will be loose and loopy.

Loose upper thread requires the top tension to be increased (higher number).

When threading the top thread, be sure to ALWAYS RAISE the presser foot while threading so the thread will seat properly in the tension disk.

If the bobbin thread is loose, then the bobbin tension needs to be tightened.

Understanding Thread Tension Threads

Is your top thread not pulling the bobbin thread up? This would be top tension too loose. FYI--be sure to ALWAYS RAISE the presser foot when threading the upper thread so it will seat properly in the tension disks.

If the bobbin thread is loose, then the bobbin tension may need to be tightened.

Understanding Thread Tension Threads

Sound like your top thread tension is loose try increase the tension.

Loose on bottom is usually caused by too loose tension on top thread, check top tension and thread is in the tension device.

Check the threading and tension on the TOP thread through the needle. When you pull on the thread is there tension? Try increasing the tension as it is the top thread that you see effected on the bottom side of the seam. The best way to do this is to unthread the top side completely and rethread it again to make sure you have it threaded correctly, then check that top tension as I said above.

You can also check that the bobbin tension isn't too tight but it is most likely the top tension is too loose when it looks that way.

Check the upper tension unit for loose threads or fluff. This causes the discs not to completely close when the presser foot is lowered.

You need to get the tensions set correctly, sounds like either you have not gone through the tension discs or the top tension is too loose.

that means your top tension is incorrect, be sure to make sure your machine is threaded correctly and that your tension assembly is working correctly,,,,,,easy fix!