The thread is loose at bottom - Sewing Machines

Are you sure which thread is loose?... upper top spool or bottom bobbin? If possible use a different color thread on top or bottom to be sure.

If upper thread is not pulling back with take up arm you need to increase upper thread tension.

If the bobbin thread is loose, then the bobbin tension spring needs cleaned and/or adjusted.

Have tried different thread lot or manufacturer?

Um, the top thread is showing on the bottom of the fabric? The top tension is too loose. The two threads create a tension battle, one pulling against the other. To pull the bobbin thread up, tighten the top tension. The tension is accurate when the two threads meet "in the middle" of the fabric. On thinner fabric, you might see a tiny spot of bobbin thread on the top and a tiny spot of top thread on the bottom.

the needle thread tension is too loose
tighten it up so that it pulls the bottom thread up into place

Usually, loose threads under the fabric indicate a loose upper tension. Be sure that you RAISE the presser foot BEFORE threading the upper thread. This allows the thread to seat properly in the tension guides. If the loose threads are still appearing under the fabric, try tightening the upper tension. The upper and lower threads should meet in the middle of the fabric.

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Loose on bottom is usually caused by too loose tension on top thread, check top tension and thread is in the tension device.

The sewing on the bottom is loose because you don't have enough tension on the TOP thread. First, make absolutely sure you are threading the machine correctly. Next, while using 2 different colours of thread, tighten the top tension dial one number at a time and then checking the stitching, continue tightening the top tension until the sewing is even on the top and bottom of your cloth.

try this site
sewusa.com they have some threading diagrams
also youtube has video's
for a manual
sewingpartsonline.com
sew4less.com
a1sewingmachines.com
since the bottom thread is loose try adjusting the top thread tension

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.

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.