Just another hint . My machine has just done a similiar problem . I knew it was the bobbin almost empty of thread. Stopped filled bobbin put back hey presto no more birds nest.

it could also be your bobbin is not wound right so try another bobbin to. Or you don't have enough thread on bobbin when it gets low sometimes that happens.
Deb

Love the phrase "how I was holding my mouth". My mom used to say, "You're not holding your mouth right." when she would see us struggling with something.

Not sure what machine you have, but my 6600 does this once in a while....all I have to do is turn it off and then on....some "technical" glitch in the tension discs....or sometimes the thread pops out of the guides.

You ladies and gentlemen are the best, I tried all of your suggestions and now I am sewing beautifully. I think it was really dirty as I got all kinds of dust bunnies out of the machine. I also changed the bobbins and the thread. Thanks for all the advice.

"You're not holding your mouth right", got a big smile from me! When this happens to me, it's because my top tension dial has moved (on it's own), all the way down to "0". I have to be soooo careful about touching it. Just a "glancing blow" will cause my dial to move. I've taken it in to have it fixed and it's better. It used to move on it's own.. just the action of the machine sewing would cause it to move. So... I'd check your top tension dial.

Glad to hear that it's sewing like it's supposed to again! :thumbup:

So glad you're sewing along beautifully again!

Yeah, that "holding your mouth right" must be the tricky thing I have to try sometimes too!

If the thread nest is on the bottom it is from the top thread. Clean the machine, oil it, put in a new needle and try again. Sometimes thread gets tangled up in the tension disks and causes lots of grief.