The top thread isnt working its all loose - Brother XR7700

Increase the top tension to pull the thread into the material.

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sewing machine tension explained

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I'm not familiar with this machine but it sounds as though your top tension is too tight so that when you sew through heavy material the thread isnt slack enough to go through that extra thickness and so simply snaps. Try reducing the tension a little at a time and see how your stitching is affected.
Another issue might be that you are trying to sew a heavy fabric and using too light a thread. You need to match your thread to the job in hand. For a thicker thread you need heavier top tension. If your machine has been correctly serviced you should not have to alter the bobbin tension at all under normal circumstances as thicker thread will automatically have a heavier tension as it goes under the bobbin case spring and so you have to match this heavier tension with a higher top tension in order to get a perfect lockstitch.
I hope this helps.

Pull a bit on those loose stitches and verify it is actually the bobbin thread that is loose. Usually, the looping is the top thread. As a general rule, if the thread problem appears on the bottom of the fabric, it's a top thread issue. If the problem appears on the top of the fabric, it is a bobbin thread issue.

If it is a top thread problem, try increasing the top tension. If it continues to create loops under the fabric, you need to rethread the top thread as follows:

Remove the top thread from the machine.
ALWAYS RAISE the presser foot and rethread from the beginning.
Then tweak the top thread tension until the top and bobbin threads meet in the middle of the fabric.

Increasing the top tension will bring the bobbin thread higher into the fabric. Decreasing the top tension will allow the bobbin thread to pull the top thread down into the fabric. You want a happy medium between the two. That is correct tension.

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...

When the underside of the stitching is loose the problem is most likely with the top thread. Unthread the machine then rethread it making sure that the thread is securely in the tension disk and the machine is correctly threaded.

Pull at least 6" of thread through the needle's eye and gently holding both thread tails gently when beginning to sew. Might try installing a brand new needle--make sure it is installed correctly. Raise the presser foot BEFORE threading the upper thread.

Pull bobbin thread to the top of the fabric before taking the first stitch.
How and Why to Bring up the Bobbin Thread

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Usually thread too loose on the bottom is caused by the upper tension being too loose. The top and bottom tensions work together with the top thread making the underside of the stitch seem too taunt or too loose and the bobbin thread causing the top side of the stitch to be loopy or too tight. Select a large zig zag stick and sew a couple of inches. Then examine the stitch. It should look identical on both sides. Look to see which side is drawn too tight, the zig zag being smaller on that side with threads from the bottom threads pulled through. Then adjust the two tensions so that they make a uniform, identical stitch.

Also, when the bobbin tension is right you can hold the bobbin dangling by the thread and it won't spool out to the floor but will let loose a bit with a slight flick of the wrist. Too loose it will just spool out. Too tight and it won't drop at all. When you get that set right then do the above zig zag test to see where the top tension should be set.

when you have the foot down ready for sewing,the needle thread , pull on it slowly and make sure there is resistance through the top tension, if there isnt any then the tread will ball up underneath

Check the ovious things first make sure you needle isnt broken... then make sure there isnt any thread twisted inside your bobin housing. make sure bobin is inserted correctly if those things dont help it could be an issue of timing in your machine... I work as an embroidery operator in a factory setting and those things usually help..

This is a tension adjustment problem. It's good to use two different colors of thread, like you did. From your description, the top thread (needle thread) tension needs to be tighter. As you tighten the tension of the top thread, you'll see that the top thread pulls the bobbin thread up into the fabric so it's no longer laying loose on the bottom of the fabric.

You'll need to have the pressure foot down when you tighten the tension. Tighten it a little, sew a practice seam, check to see what the stitch looks like. Tighten it a little more, sew, check, etc etc--until both top and bottom look the same--you shouldn't see much (if any) of the bobbin thread color on top of the fabric or the top thread color on the underside.

Let me know how this works for you, ok?


Robbie