I have a Pfaff 2170. Today I set it up for embroidery and started a sample - thank goodness it wasn't my 'real' fabric! BIRD'S NEST.

Instead of doing any more embroidery, I decided to test the machine with regular sewing. The sample showed terrible tension - top thread pulling to the bottom.
I reset the tension every way I could think. It remained the same when I sewed no matter how it was re-set.
I made sure the foot was in the correct position.
I took out the bobbin and made sure I put it back correctly.
I rethreaded the needle.
I took out the needle and put it back in.

No matter what change I made, the tension remained the same.

I called my Pfaff dealer and found out she's no longer in business. I went on-line and found out the nearest Pfaff dealer is in NY, and I'm in CT. I'll call them Monday - I'm too upset today!!!!!!!!!!!!

Try a different bobbin :wink: Plastic ones can get burrs and they all may not wind correctly once in a while too :D:D:D

I almost never have to reset my tension. That problem is often caused by the threading not being exactly right. Or a very small bit of fuzz in or around the bobbin case.

did you totally rethread? take the spool all the off and start brand new, be sure you don't miss any of the guides and be sure the foot is up so that the thread goes into the correct groove of the tension guides, pull the bobbin thread up, hold it and try again
good luck

i agree you need to take the top thread completely off the machine and re thread it sounds like it is not in top tension correctly or not in the take up bar sometimes my thread jumps out of the take up bar good luck

There maybe dust in the bobbin area or in the bobbin case.
Take out the throat plate check for a pice of thread or even a dust ball.

you could try and run a peice of ribbon threw the top tension like your are going to thread your machine, might be some thread caught in the tensions.

Make sure the thread is spooling off correctly on the bobbin when you put it in the machine as well as the thread on top.

If all else fails try a new needle. Check for thread bits, dust all visible places, use a long piece of dental floss threaded through your tension disks to see if it will catch a stray piece of lint or thread. Oil the machine if your manual gives instructions for it. Check the manual to make sure your bobbin is unwinding properly. Change the spool of thread to a different brand to see if that helps. Good luck!

if all else fails , get a big hammer lol just kidding