When I sew, the stitching is loose with large loops on the underside of the fabric making the bobbin thread slide out easily. How do I fix that?

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.

Sewing Machine Thread Bunching Up Here Why

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

TIP Avoid Thread Bird Nesting with these Four Tips Stitching Sewcial

Troubleshooting Thread Nesting Sew Toot

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.

..

loops under fabric means top tension needs to be tightened
try cleaning the top tension dial with some unwaxed dental floss and see if that helps. if it doesn't then the tension dial may need to be replaced
also check to make sure the spool of thread is not getting caught on the spool holder
also try a new needle--one that is correct for the fabric being sewed

If the loops are forming on the bottom it is the TOP thread tension you need to check. Make sure it isn't too loose. Also is the needle the right type and size for the fabric? Check the stitch out on plain cotton fabric if a tension adjustment doesn't fix it.

The TOP thread effects the UNDERSIDE of the stitch and the BOBBIN thread effects the TOPSIDE of the stitch :)

Loops stitches on the underside is typically from the TOP tension being too loose, however it can also be the bobbin tension is too tight, or a problem with the needle. I would check them in that order.

Hold the bobbin thread and let the bobbin dangle. A slight shake of your hand should allow the bobbin to move downward (lets more thread out) but not so much that it just drops to the floor. When you put it in again and try sewing look at the top stitches. Do they look overly tight? THen the bobbin tension is too tight. The stitching should look the same top and bottom with no loops.

If both tensions seem to be alright check to see if the needle is: 1. the right size and type of the fabric 2. not bent

That should fix your problem :)

1. Loosen needle screw & insert needle with shank's flat side facing front of machine. Push needle in all the way, then tighten screw to hold needle in place.
2. Install a fully wound bobbin by loosening bobbin nut & placing bobbin on top. Re-attach bobbin nut & tighten. If standard thread spool will be used, then attach spool pin to bobbin shaft & place thread spool onto shaft. Attach white spool cap on end of thread spool, then tighten. Bobbin/spool should unwind facing forward toward needle.
3. Bring end of thread through thread guides & over tension control. Pass end of thread through needle eye, from back to front, & pull it out about two inches.
4. A spring pushes pressor foot onto fabric that is being sewn, so lift pressor foot & place fabric underneath.
5. Turn large handwheel on side of machine (handwheel can be turned in either direction) to raise needle arm to its highest position.
6. Holding the Handy Stitch in place with your right hand, press on power switch & begin sewing. Guide fabric (being sewn) with your left hand.
7. To end this sewing session, turn off power. Turn handwheel to raise needle to its highest position. Carefully pull out about three inches of thread through needle & snip, then lift pressor foot to remove fabric. Turn fabric over & loop needle threader through last stitch. Place end of thread from underside through eye of needle threader, & pull to loop through. Pull to tighten and snip end of thread.

Refer to the manual for cleaning.

Replace the needle with the size recommended for the type of fabric being sewn. The flat side of the needle is usually facing the back of the machine - check manual to be sure.

Always thread any sewing machine with the presser foot up. This opens the tension control so the thread can properly enter this device.

When a sewing machine is threaded with the foot down, the tension control closes and the thread cannot enter as it should

You then get loose stitches because the top thread and bobbin thread cannot make a proper stitch and the tension of the bobbin thread is pulling the top thread to the underside of the fabric.

Hi Lou! This sounds like a tension problem--the tension on the top thread is too loose. Try using different color threads on the top and bobbin, then carefully rethread everything. Stitch a couple of inches and check the underside. If the top stitches look fine and the bottom ones are loose and loopy, and with the pressure foot down, tighten the tension. Move the knob or dial (whichever you have) just a little bit. Sew a couple of inches more, and recheck. Continue to sew and recheck, gradually tightening the tension, until you see little if any bobbin thread on the top or top thread on the underside of the fabric.

Let me know if this helps, ok?


Robbie

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

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.