Bobbin tension have tried all settings for tension for bobbin. thread is too loose in the bobbin. the stitch is fine on top of fabric but too loose underneath the fabric.

Are the two threads forming a stitch but just very loosely? If the top thread is merely laying on the surface of the fabric and the bobbin thread loop is appearing on the top, it sounds like the bobbin tension is too loose. Tension is correct when the top and bobbin threads meet in the middle of the fabric. In this case, your bobbin needs to be pulling the top thread down into the fabric.

Understanding Thread Tension Threads
NOTE--before making any bobbin tension changes, be sure to mark where the beginning tension is set, ie the slot on the screw. If you make a mistake, at least you will know how to reverse your changes.

If your machine is not forming any stitches (be sure to try a brand new needle), then it has probably been knocked out of time. Search for "sewing machine timing" or take it for service.

You need to tighten the bottom and top stitches both. First, tighten the bobbin slightly. Now, tighten the top stitches the same amount of pressure as the bobbin. The attempt is to have both the bottom and top stitches exactly the same so the final stitch ends up in the center of the fabric. Observe the stitch and readjust if necessary.

Yes Adjust to more tight see what it'll do.
Bottom bobby is too tight or upper thread control is too lose.

Good luck

Mai

If the thread problem appears under the fabric, it is a top thread issue.

If the thread problem appears on the top of the fabric, the bobbin thread is the issue.

Perhaps the upper thread is not seated completely in the tension disk. Remove the upper thread from the machine, ALWAYS RAISE the presser foot, then rethread from the beginning. Make sure the thread path is correct. Test your stitch.

If the thread is still looping under the fabric, the upper tension is too loose. Set the upper tension to the midway point. Test and adjust the tension until it is where you want it. Preferred tension is when both threads meet in the middle of the fabric.

sewing machine tension Google Search


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Am having a difficult time picturing this. Sounds like the upper thread is creating loops under the fabric and the bobbin thread is showing on the top of the fabric.

Make sure to use a brand new needle.

Remove the thread from the machine
ALWAYS raise the presser foot and rethread the upper thread.
Make sure the thread path is correct.

Check that the bobbin is turning the correct direction in the bobbin case and the bobbin thread is threaded through the bobbin tension correctly.

Set the upper tension to the midway point (factory standard), however, this setting may need to be tweaked for your particular machine.

Bring the bobbin to the top of the project Before beginning to stitch.
How and Why to Bring up the Bobbin Thread

Retest--begin sewing slowly.

If the upper thread is still showing on the other side of the fabric, the tension is too loose. If it is pulling the bobbin thread up to the top of the fabric, the upper tension is too tight

OR the bobbin thread tension is too loose. (CAUTION: make only small adjustments to bobbin tension--1/8 of a turn at a time!!! It also helps to mark the screw groove location with magic marker on the bobbin case BEFORE making any changes so you can back it out and return to the original setting.)

Bobbin Tension How and Why Tension is Adjusted

Understanding Bobbin Tension

Understanding Thread Tension Threads

Sewing Lesson 10 How to Fix Tension on Your Sewing Machine

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First, try a brand new needle.

Second, consider using a better quality thread. By all means, AVOID old or bargain bin threads. Coats & Clark used to be a standard, but thread quality has improved over the past few years, so you may want to check out other brands like Aurafil, Superior, Isacord, etc. Also, cotton wrapped polyester thread releases thread lint that contributes to build-up of gunk in the machine. Some sewists have noted that they experience more sewing issues when using C&C threads. However, some machines will do better with certain thread brands than others, so some experimentation may be beneficial.

Third, check the stitch on your sample again. Generally, when thread loops appear on the underside of the fabric, it is the upper thread that is the problem. If loopy threads appear on the top of the fabric, it is the bobbin thread that is the issue. You can even use a different color in the top to help distinguish which thread is the problem.

Fourth, when threading the upper thread, Always Raise the Presser Foot during the threading process so the tension disk is released and the thread can seat properly. "Bird nesting" occurs when the thread is not seated in the tension disk.
Sewing Machine Thread Bunching Up Here Why

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

Fifth, when the upper thread appears on the underside of the fabric, the upper thread tension is too loose. If the bobbin thread appears on the top of the fabric, the tension thread is too tight (or the bobbin thread is loose). Start out with the upper tension set at the midway point and tweak it from that point. The tension is ideal when both upper and bobbin threads meet in the middle of the fabric.

Also, remember that tension is not static--a tension setting for chiffon will most likely not work on cotton or denim. Get comfortable adjusting the tension to suit the project you are sewing.

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it's very possible that the machine is slightly out of time & needs to be service at a sewing machine shop
is the fabric & thread & needle compatable with each other?
did you use every thread guide when threading the machine?
is the bobbin in correctly?
is the bobbin warped?

A. To correct loose stitches, try the following: (1) Balance the thread tension. If the stitches are loose on top of the fabric, decrease the tension to the next lower number. If they are loose on the underside set the tension to the next higher number. (2) Make sure the needle/upper thread follows the threading path. (3) Check to see that the bobbin case is threaded properly. (4) Use a different size needle. For fine fabrics, use a smaller needle (size 9, 11); medium-weight fabrics require a size 14 or 16. And use a size 18 or "Denim" needle for heavy corduroy or denim.

Hi! The bobbin tension rarely needs to be adjusted. First, make sure you're using the appropriate size needle and thread for your fabric (I'd probably use either a 'denim' needle or a universal size 14) and also that the upper thread and bobbin are threaded absolutely correctly. These can throw off the tension! Also, take the time to clean out the bobbin area. That can throw your stitch off also.

If the stitch on the bottom is loose, so that you see the top threads, then the top tension is too loose. If the top stitch is too loose and you see the bobbin threads on top, then the top tension is too tight.

It helps to thread the machine with different color thread on top and in the bobbin, and then stitch an inch or so on the same type of fabric as you're using in your quilt. Check the stitch. If you need to adjust the top tension, make sure the pressure foot is down! Adjust a little, stitch a few inches, and check again. Repeat until you don't see any (or very little) bobbin thread on the top or top thread on the bottom.

If you go through all these steps, and the bobbin thread is still loose (and you've tightened up the top tension), then there is a tiny little screw on the side of the bobbin case that you can use to adjust the bobbin tension. Turn the screw just a little bit (less than a quarter turn), stitch, check, etc. Once the bobbin tension is set, you shouldn't ever have to change it.

Let me know if this helps, ok?

Happy sewing!

If the top stitch is loose, then you need to tighten the bobbin tension: if the bottom stitch is loose, tighten the top tension. Hope this helps. It could also be the size needle and thread you are using for a particular fabric. Different fabrics require different notions.