Model #5050: the top stitch looks fine but underneath, massive loops. I've changed the needle, rethreaded the bobbin, altered the thread tension, but still the problem remains. Any ideas? Margaret W.

Looping and nesting on bottom side is usually a top thread tension too loose (or no tension). Always thread machine with needle up and presser foot up. See singer video https://www.youtube.com/watch?v=O7N4XaIV6ms


Less likely is bottom thread has escaped the bobbin case tension spring, but this usually results in a jammed hook.


If still having issues comment here so I may assist further.

You are getting a thread mess under the fabric? Frequently, this occurs because the top thread is not fully seated in the tension disk.

Install a brand new needle.
Remove the top thread from the machine.
ALWAYS RAISE the presser foot and rethread the machine from the beginning.
If necessary, adjust the top tension so the top and bobbin threads meet in the middle of the fabric.

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

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top tension is incorrect
pull the top thread out and there should be resistance to pulling it before you thread the needle

not sure if this will help you...Check Your Tension Settings. Looping underneath the fabric usually occurs when there is not enough tension in the needle thread to pull the bobbin thread. Sometimesthread buching can be caused by something as simple as the tension dial being inadvertently turned.

WHY IS THREAD BUNCHING UNDERNEATH MY FABRIC ? ' eBay

www.ebay.co.uk/gds/WHY-IS-THREAD-BUNCHING-UNDERNEATH-MY.../g.html..
or you could go to this link and see if it helps you out.. thread keeps looping Google Search

You may need to adjust the tension knob for the thread . Usually located above the needle . screw it in a little at a time or perhaps it has a number scale if so increase to a higher number a little at a time till the stitches become correct.

increase the thread tension of the needle thread
this is an indication that the tension is not enough to pull the bobbin thread up tight

try changing the needle first--make sure the needle is the correct one for the fabric being sewed.
if you've adjusted the top tension & the bottom stitch still looks the same
it's possible that the top tension dial is needing to be checked to see if it's
working correctly

no, more likely your top tension is too loose causing the loops on the underside of your fabric, loops on top would be bobbin too loose. raise presser foot and rethread top thdead pulling thread into tension fully. set top tension dial to 5 and test sew. if still looping underneath try tightening top tension by turning dial up to 6. but usually top tension should only need minor adjustment tweeks. you can test top tension by lowering pressure foot to engage tension and holding thread just above needle thread guide, pulling thread downwards . there should be resistence on it to your pull. if you cant feel any then tension device may be faulty, and require service.

If the machine is now threaded, lift the presser foot.

Now, pull about 10" of thread through the needle.

The next time you thread the machine, lift the presser foot first.

When the presser foot is up, the tension control opens and allows the thread to "seat" into the control, then when the foot is down the control closes to the indicated setting.

When threading the machine with the foot is down, thread does not enter the tension control and when you start to sew, there is no tension on the thread.

No tension = loosey, goosey, loopy stitches underneath.

Because the lack of tension on the top thread, the bobbin thread cannot lock a proper stitch.

If the thread is loose on the bottom of the fabric, it's actually the top thread is too loose. Think of 2 little elves playing tug of war in your machine, one on toip and one underneath. If you have loops on bottom, the top needs to pull harder (tighten top tension)