Bottom thread is looping on top of fabric on my Singer Futura 400 machine

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.

K McMurdo's answer is correct.
Further: you will need to balance the tension between the top and bottom thread. After LOOSENING (anticlockwise) the screw on the bobbin case with a good quality thread wound on the bobbin. pull it out to see that it is tightened slightly. Put the same thread on the machine and carefully thread up the machine. A very high proportion of bad stitching problems is caused with incorrect threading of the machine. Set the machine tension at a mid point and slowly pull both threads to approximate that the tension is approximately equal on both. Keep the presser foot up while doing this. If the bottom thread keep adjusting the screw on the bobbin case until you get the threads roughly even. You can then try sewing and adjust the top thread until you have the stitch loop bedding in the fabric. It is essential that you have a needle that is appropriate to the fabric and thread you are working with!

Best Wishes, Ray

Most likely there are jamming threads at bobbin room under the machine stepping pedal, try to dismantle it to get rid of these threads.

You're probably correct. The new Singers are not what they used to be...Singer was bought out a few years ago and many buyers have registered their regrets and disappointment with the new products and service.

http://evadman.blogspot.com/2011/12/singer-xl-400-futura-sewing-embroidery.html

Most complaints about sewing machine problems concern thread loops under the fabric, which are usually caused by the upper thread. Your problem is not as common. Generally, when thread problems occur on the top of the fabric, it is a bobbin issue.

Try a brand new needle. Make sure the needle, thread, and fabric are compatible. Also, check that the needle is installed correctly.

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwjV3sKLxKvNAhUjE1IKHdbNDb4QFggkMAE&url=http%3A%2F%2Fwww.schmetzneedles.com%2Flearning%2Fpdf%2Fschmetz-needle-chart.pdf&usg=AFQjCNHTR52AmqwzvyCjbXmD5Ch52Va5_Q

All About Needles

Remove the thread from the machine. Check that the machine is clean--no lint, dust bunnies, thread pieces in the bobbin area, stuck in the feed dogs, or under the needleplate.

ALWAYS RAISE the presser foot when threading. Rethread the machine from the beginning. Check that the thread path is correct for the upper thread and that the bobbin case is loaded and threaded properly. Use the same thread for both upper and bobbin.

Most machine standard upper tension is set at the midway point. However, this is just a beginning point. The tension differs from one machine to another and may need adjusting depending on the fabric you are sewing.

Retest your machine.

If loops are still forming on the top of the fabric, then the bobbin tension may be too loose. Try tightening the bobbin tension (only 1/8th of a turn at a time!).

Understanding Thread Tension Threads

Sometimes it is a thread issue. Experiment with different brands of thread. Avoid old or bargain bin threads (the thread in bins at the fabric store are not the best, also Coats & Clark may not work well in your machine). Stick with better quality threads, ie Gutermann, Aurofil, Isocord, etc. Be sure to use the type of thread that is suitable for your project, ie do not use embroidery or cotton thread for sewing garment seams unless you want to be embarrassed when the seams start popping... Polyester used to be the bane of sewing projects but is now used for many items because the quality has improved and, in some cases, surpassed the former favorite cotton. Polyester is light weight but strong. Some machines just do better with one brand of thread over another.

You may also consider testing the machine with different types of fabric to see if it performs better with a particular fabric type or weight.

If it continues to be a problem, perhaps the bobbin case is damaged or malfunctioning. If you cannot find the answer to your problem, you may just need to take it for service.

http://jennys-sewing-studio.com/index.php/product-lines/singer-futura-quartet/75-singer-futura-quartet/155-faq-about-the-singer-futura-xl400.html



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If the bottom thread is tight there should also be loops on top and this means that the upper tension is too tight.
Get out your manual (http://www.singerco.com/uploads/download/1198_8763-efs.pdf) and turn to page 24. Under "ADJUSTING TOP THREAD TENSION" it tells you that if you're having thread tension issues, change the tension control dial on the top of your machine from auto. It also shows you a diagram with your problem illustrated on the right side of the page. The bobbin tension is set at the factory, so all tension problems can be solved with top tension adjustment. Set it manually and if it loops on top, loosen the tension a little. Test again. Repeat until loops are gone.
Using different colours on top and bobbin and a contrasting fabric (e.g. black top, white bottom, light blue fabric) means you can easily see what's happening. A perfect stitch is when you see exactly the same stitch pattern on both sides of the fabric. On top, the bobbin thread colour appears between stitches as a tiny dot and on the bottom, you see the top thread dot between stitches.
If it's impossible to get the tension right, take it to a technician, because it's a sign that the hook timing needs attention.

bobbin thread is too high pressure or too low pressure on teh top adjustment!

remove bobbin and turn tension screw about 1/8turn left (anticlockwise) check if still grabbing, if so - top thread turn about 1/4 turn (at embroidery ir should do automatically, but sometimes need kick...).

check if it is still grabbing on the bottom, do it grab during straight? zigzag? double zigzag? if do not - setting on the pattern need to be look at. if it tangle as well on these three - need definitely servicing...

follow manual how to adjust.

Tension between top and bottom is a BALANCE, and when the bobbin thread shows on top, it means that your top tension is tighter than your bobbin tension, so it is pulling the bobbin thread up above the fabric.

Loosen the top tension to balance it--it should only take a couple of "ticks"--no more than one number. Loosening the top tension, by the way, is AWAY from the "S".

change the needle
make sure the bobbin is inserted correctly into the bobbin case
make sure the top thread has not come off the thread take up lever
also try adjusting the top thread tension

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

Sad to say you might have to do an indept check. Like start with a small peice of fabric - start with the highest bobbin tension and go to the lowest - leaving the top tension the same. Write all the findings. Then do it all again with the next top tension. Keep your 'good' findings in a little notepad in your sewing box. Then you will have it all ready for any other project. Good luck!