Singer-tension My machine is having a similar problem. The top thread looks fine while the under side is a complete mess and just pulls out. I have tried adjusting the tension over and over with no different results... do you have any other suggestions?

Loop and nesting on bottom side is usually top thread tension too loose (no tension) but can be bobbin thread tension issue. Be sure to thread per machine instructions.

See following Singer video... testing top thread tension.
https://www.youtube.com/watch?v=O7N4XaIV6ms
Test tension of top thread.
With needle up, presser foot up, and tension select = 4, thread machine. Then make a long slow steady pull of top thread. The thread should advance smoothly through needle eye without snagging from top spool. Now lower foot and make another long slow steady pull of thread. Again it should advance smoothly through the needle eye. Note difference no tension (foot up) and selected tension (foot down).


If no difference in foot up/down tension then something wrong with the tension selector or not threaded properly, consult machine manual.


You can do a similar test of bobbin thread tension. Make a slow steady pull of bobbin thread. It should advance smoothly from bobbin with tension similar to top thread with tension =4. If bobbin tension is similar to top thread foot up, then likely bobbin thread has escaped bobbin tension spring... reload bobbin per machine instructions.

Adjustment of bobbin tension is rarely needed. Loop and nesting on bottom side fabric is usually a top thread tension too loose.



See Singer video https://www.youtube.com/watch?v=O7N4XaIV6ms


Test tension of top thread.
With needle up, presser foot up, and tension select = 4, thread machine. Then make a long slow steady pull of top thread. The thread should advance smoothly through needle eye without snagging from top spool. Now lower foot and make another long slow steady pull of thread. Again it should advance smoothly through the needle eye. Note difference no tension (foot up) and selected tension (foot down).


If no difference in foot up/down tension then something wrong with the tension selector or not threaded properly, consult machine manual.


You can do a similar test of bobbin thread tension. Make a slow steady pull of bobbin thread. It should advance smoothly from bobbin with tension similar to top thread with tension =4. If

Loop and nesting on bottom side is usually a top thread tension or top thread feed issue. Be sure needle isn't barbed at tip. If your machine has a horizontal spool pin, be sure the spool cap is larger than the spool and the thread unwinds from spool per machine instructions.


See Singer video https://www.youtube.com/watch?v=O7N4XaIV6ms


Test tension of top thread.
With needle up, presser foot up, and tension select = 4, thread machine. Then make a long slow steady pull of top thread. The thread should advance smoothly through needle eye without snagging from top spool. Now lower foot and make another long slow steady pull of thread. Again it should advance smoothly through the needle eye. Note difference no tension (foot up) and selected tension (foot down).


If no difference in foot up/down tension then something wrong with the tension selector or not threaded properly, consult machine manual.


You can do a similar test of bobbin thread tension. Make a slow steady pull of bobbin thread. It should advance smoothly from bobbin with tension similar to top thread with tension =4. If bobbin tension is similar to top thread foot up, then likely bobbin thread has escaped bobbin tension spring... reload bobbin per machine instructions.

What you are seeing is called "bird's nesting." There are two main reasons for "bird's nesting."
The first one is the thread not between the tension disks. That allows the thread to be pulled from the spool instead of pulling the thread tight from underneath. Always make sure to always put up your presser foot before you thread the tension disks. I also check the thread after I finish to make sure the top thread has good tension on it before sewing.
The second reason is the thread is not being pulled by the take up lever. Make sure you see it being pulled by the take up lever before you start sewing. If not, rethread it.

Good luck.

Is it really the bobbin thread that is globbing? Check closely. Usually it is the upper thread accumulating under the fabric.

If it is in fact the bobbin thread, then the bobbin case is not threaded correctly, the bobbin case tension needs adjustment, or it is broken and needs replacement. There are web sites and YouTube videos that show how to adjust the bobbin case tension.

QUICK FIXES: Remove all the thread from the machine. Clean the area around the feed dogs and bobbin area. Oil as instructed in the owner's manual using ONLY fresh, good quality sewing machine oil (only 1-2 drops each spot). Install a brand new needle insuring it is installed correctly. Avoid using fuzzy, old, or bargain bin thread. Rethread: Be sure you raise the presser foot BEFORE threading the upper thread so it will seat properly in the tension disk--and check to make sure you are threading the machine correctly. Check that the upper tension is set properly (the factory standard is usually the halfway point between the high & low number on the selection). Test on a scrap of the fabric you wish to sew. Adjust the upper tension--either tighten to pull the upper thread toward the top of the fabric, or loosen to pull more upper thread down.

Here are some web sites that may help.

Sewing Machine Thread Bunching Up Here Why

sewing machine birdnesting

https://answers.yahoo.com/question/index?qid=20100303212248AAnRUQA

8 Tips to Fix Birdnesting in Embroidery

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

http://www.marthastewart.com/1085057/common-sewing-machine-repair-tips


and here's another Hint that may be helpful:

https://www.youtube.com/watch?v=KDERq4I7l-Q

...

change the needle --make sure it's the right one for the fabric
being sewed

rethread the machine top and bobbin

make sure the bobbin is turned the right way in the bobbin case

also check the top thread tension, if the stitches under the fabric
are loose adjust the top thread tension one number or letter higher
at a time and sew on a scrap piece of fabric till the stitches look
normal

here is a free manual
http://www.singerco.com/uploads/download/696_5417c.pdf

try these suggestions
1. change needle--flat side goes to the back of the machine
2.check the thread take up lever & see if the top thread stay on it or jumps off, that can make the birds nest you mentioned
3.top tension ususally is on 3 or 4
if you don't have a instruction manual follow these steps
Go to the singer website
Go to the home page
Go to customer service--click on it--it will show a small menu--click on instruction manual
In the box put the model number (example 4562 ) & click search
if search comes up with nothing then contact singer customer service
and ask them

Check your top tension. It sounds like it may be too loose or the bobbin tension may be way too tight. Most likely it is the top tension that is incorrect though. The TOP tension effects the bottom side of the stitch and the bottom tension effects the top. If the top tension isn't tight enough it won't draw the thread up through the top side taunt enough and the excess underneath makes a big loopy mess.

If you are getting a thread mess under the fabric, it is a top thread problem.

Remove the top thread completely from the machine.
ALWAYS RAISE the presser foot and rethread from the beginning. Verify the thread path is correct.
Retest your machine and tweak the tension, if needed.

...

angle the bottom might be a mess but it is the top thread that
you see balled up .Pull the top thread and make sure there is tension on it ,if not check the thread is between the discs and there is nothing else between them .if this is ok there is something stopping the top thread from being pulled back up
through the needle plate to form a good stitch,if you can turn by hand and watch where it is catching you might be able to solve it.