Tension problems - Simplicity Fashion Pro SW2145 Mechanical Sewing Machine

1. Replace thread with good thread. (Check by holding to light to see if there is fuzz).
2. Adjust the bobbin tension. The tension on top is set to three and the bobbin tension should be equal to this amount.
3. Replace needle.
4. Check the top tension with tension foot down to see if the thread can move or does it get stuck? If it gets stuck the tension control may need adjusted or cleaned.
5. Pull the bobbin thread above the throat plate and pull on the thread. It must have some tension but not get stuck.
TENSION TENSION TENSION IS THE PROBLEM!

Be sure to RAISE the presser foot when threading the upper thread so it will seat properly in the tension disk.

The tension is correct when the upper and bobbin threads meet in the middle of the fabric. Upper tension is static and should be tested and re-adjusted every time a new project is begun as the needle/thread/fabric will alter the tension result.

Understanding Thread Tension Threads

Oh You Crafty Gal Sewing Lesson 10 How to Fix Tension on Your Sewing...

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=7&cad=rja&uact=8&ved=0ahUKEwii7pK396TMAhVJuoMKHUrgAnkQFgg4MAY&url=http%3A%2F%2Fwww.ca.uky.edu%2FHES%2Ffcs%2FFACTSHTS%2FCT-MMB-213.pdf&usg=AFQjCNE4QlGk1Fvt8K2UGCRCfzMpGS-A2Q

10 Tips for Taming Sewing Machine Tension Problems

Adjusting Sewing Machine Tension to Prevent Problems

..

is it a upper tension or lower tension problem?

Be absolutely sure that the problem lies with the bobbin tension. 99.9% of tension problems lie in the "upper tension." If upper thread is creating a birdsnest under the fabric, the upper tension is too loose. If the bobbin tension is pulling to the top of the fabric, the upper tension is too tight.

One should adjust bobbin tension only when one is very familiar with a sewing machine. Before changing anything, be sure to mark the position of the bobbin tension adjustment screw first. That way, you will be able to return it to the original position if you need to. When making bobbin tension adjustments, move the bobbin screw only 1/8 of a turn at a time. Test before making any more adjustments. Repeat, test, repeat, test...

...

Not sure, but am thinking perhaps the tension disk has gunk or threads stuck in it. Try soaking a length of perl cotton in rubbing alcohol, squeeze out the excess. Raise the presser foot and loosen the tension disk as far as possible and gently pull the perl cotton DOWN through the tension disk a few times.

If that doesn't help, then it's possible a spring in the tension mechanism or something in the presser foot lever is malfunctioning.

the bobbin tension is set by that small spring plate that you pull the thread under after you put the bobbin back in the carrier / holder
a very small turn of that screw makes a big difference ob the tension unlike the needle thread tension
mostly the problem ( you never bothered to mention the symptom ) is bird nesting under the fabric which is the needle thread tension not tight enough

It's probably assembled ok. If you're trying to adjust the tension with the pressure foot up, it won't work. The pressure foot needs to be down in order to adjust the tension.
Let me know if this works, ok?

Look to see if the 'check spring" is still there, and not broken.
If the tesion nob can be truned without any feeling of tension, then maybe the screw that attaches the 'tension housing' to the stem has loosen or broken.

You seem to have a tension problem or a threading problem. Try the following: Normal 0 MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman";} Tension assembly test. To do this test. Pull the thread through the tension assembly and test it to make sure the tension is working correctly.
(To do this test, adjust your tension setting to normal or medium or 5 or something in the middle. Raise the presser foot and pull the thread through the tension. It should pull easily!! Lower the presser foot and pull the thread. It should pull noticeably harder.)
If it doesn’t work this way then you probably have a piece of thread or lint stuck inside the tension discs. To remove it, turn the tension to 0 zero and raise the presser foot.Using a small screwdriver, open the space between the discs and spray with canned or compressed air. The stuff should come out. Do the tension test again to make sure you got everything and then try sewing again.
sewman7

Looping on the top means there is no tension on bottom. The bobbin thread generally rotates counter clockwise. The thread must get under the tension spring. The spring must be adjusted equal to the top tension. This you will have to play with to tighten or loosen as needed. When you sew in a zigzag you might want to loosen the top tension slightly. On a regular basis remove the bobbin case and clean with a qtip. On the race put one drop of sewing machine oil. Clean the bobbin case and replace.