Sewing machine problem

Your tension must be wrong. If the top tension is too weak the thread on the bottom is not being pulled through the fabric to form a proper stitch. Try different tensions on scraps of fabric.

Check your stitch sample. Dollars to donuts it's the top thread bird nesting (also called thread nesting) under the fabric. Issues appearing under the fabric is usually top thread related. Problems appearing on the top of the fabric is usually bobbin thread related.

Remove the top thread from your machine.
Be sure to start with a brand new needle.
ALWAYS RAISE the presser foot and rethread the top.

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Check your stitch sample. The loose stitches under the fabric--are they actually top thread???? Usually,stitch problems under the fabric is a result of a top thread problem. In this case, it could be bird nesting.

Remove the top thread from the machine.
Install a brand new needle.
ALWAYS RAISE the presser foot.
Rethread from the beginning.

Sewing Machine Thread Bunching Up Here Why

Birds nest under the fabric big loops of thread top side looks good...

adjust the tension to a appropriate setting,
See the video here.
Sewing Help Sewing Machine Problem Thread Bunching Under Fabric
The knob and its location can differ based on the model of your sewing machine.

try changing the needle--use a needle according to the fabric
being sewed
if thin fabric is being sewed try using a stablizer
rethread the machine top and bobbin--use every thread guide
make sure the bobbin is inserted correctly and turned correctly
in the bobbin case
also try adjusting the top thread tension just a little

Make sure you hold thread in back of the lowered presser foot when you begin stitching, and that the needle is piercing the fabric so that the fabric isn't slipping down into the feed dogs (under needle plate area).Hope this helps you out,alexlefebvre.Jimmy

Hi. You should never try to sew without fabric unless you are "chaining off" on a chain stitch machine or an overlock (serger).

Clean the bobbin area and then re-thread the machine with the presser foot up.

Lengthen the stitches.

Test on a scrap of the fabric.

Yes, it does. There are a couple of reasons the bobbin thread could be bunching up on the underside of the fabric. It could simply be that the machine needs cleaning. Take the bobbin assembly out, brush all the old lint out as best you can, reoil the machine once it's all clean, and make sure there aren't any little bits of thread caught in the bobbin assembly. Rethread the machine (carefully) and change the needle. This solves the problem usually--especially if the machine was sewing along fine and the problem develops suddenly. '
The other thing to check is your tension. It could be that the top tension is too loose. But different color thread in the top and in the bobbin, stitch a few inches (be sure to held the top and bobbin thread ends behind your needle as you start to stitch) and check. WIth the pressure foot down, adjust the tension, and stitch again. Keep stitching, checking, and adjusting until you see little if any bobbin thread on the top or top thread on the bobbin.
Another thing to reminder: use the appropriate thread and needle for the fabric you're sewing.
Let me know if this works, ok?

Robbie

I had this problem and it all came down to using the wrong backing. I kep trying to use tearaway on everything but WRONG. Using the proper backing corrects most problems. Good Luck!