Bobbin tension I have a Bernina 1008 and am having trouble balancing the tension on the bobbin thread. It continually makes small loops over the upper thread as the machine sews no matter what setting I place the tension. Since I need to use my machine daily for my work and there is no place near where I live to take the machine to be fixed, this is a serious problem for me.

"Nesting or Rat's Nesting" on the bottom side of Bernina sewing machines (CB hook type) is generally the result of very loose top tension. If the problem is found in newer sewing machines such as machines made after 1986 (serial numbers beginning with 26xx xxxx), may have an older Bernina bobbin case in the machine. The problem with the older bobbin cases is that the rounded projection of the latch on the left side of the casing will catch thread, preventing easy thread escapement during the take-up lever cycling resulting in loops on the bottom side and or thread breakage, etc..
Note:....Timings and modified latch geometry's were applied to later models to allow for good thread escapement. Older Bernina cases cannot be used on newer machines but newer cases can be used on all CB hook Bernina machines.
Additionally, Chinese copies of the Bernina/Cerliani OEM bobbin are rampant and can cause sewing issues. Always ask for OEM Bernina cases.

Note the following trouble shooting logic:
1. The center tension disk that is visible through the thread slot in the top cover of most machines must be positioned exactly in the middle of the top cover slot. By loosening the fixing screws on the top tension mechanism, one can adjust the disk position to center.
2. It would be a very rare situation for the top tension to change whatsoever from the (red center marking) factory setting. The most likely cause of loose top tension under the normal center mark position, would be accumulated lint, thread, or a sticky substance between the disks. This would prevent the tension compression disks from applying an even tension on the sewing yarn (thread). Often this can be blown out with compressed air when the presser foot lever is lifted in the up position. In some cases, soft drinks and other sticky or corrosive liquids can find their way between the disks. In this case, the tension assembly must be removed, disassembled, and the disks cleaned and polished.
3. Check the facial surfaces of the bobbin case for corrosion, and sticky substances that prevents the thread from easily sliding over the bobbin case.
4. Check that the spindle of the hook body is not bent or warped, causing the bobbin case to wobble, thus creating an intermittent pressure on the hook race cover at the moment that the thread is trying to escape over the bobbin case finger. (Replace the hook body)
5. Inspect the undercut on the hook body spindle for thread wrappings and knots. This condition can cause the bobbin case to press hard against the hook race cover, hence hindered thread escapement .
6. Exceedingly tight bottom tension can cause some problems as well. ( If you don't know how to adjust Bernina bobbin cases to factory settings, please ask).
7. Hook timing, (loop lift) can be out enough to affect thread escapement. This is typical of newer machines made after 1986 since Bernina no longer made fixed timed machines like the earlier Swiss made models. The later made models have timing components that can slip under stressed machine mechanics.
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Hello. Make sure the bobbin is not backward. It seems the upper tension is still not adjusted right. If the bobbin pulls smooth focus on the top tension. Good Luck

Are you sure you are getting the top thread between the tension discs? You should be able to tell the difference when you lower the pressed foot.

What is your top tension set at?

This is almost always indicative of an upper tension problem.
First, make sure you're using a good quality thread. If you're using thread that's not of European manufacture, you're probably filling your tension assemblies with little fuzzies. Coats and Clark Dual Duty is the most notorious thread for causing tension issues. If you have a bunch of this thread: throw it away or use it for hand sewing.
Turn your machine off, and use some canned air to blow out your upper tension assembly. (It looks like a couple of little cymbals inside the thread path.) Set your tension dial to 4.5.
When threading, right before you actually thread the needle itself, and with the presser foot up, "floss" the thread back and forth by holding the thread at the top by the spool with your right hand, and down by the needle with your left hand. This will ensure that you force the thread into the tension assembly.
Also ensure that your bobbin is oriented the right direction, but this would be a less common cause for your symptom.
If none of these fixes work, you probably need to have your tensions professionally calibrated.

-R

Hi: You have threaded the machine incorrectly. Rethread the machine with the presser foot up to the needle, pull the thread (loose) and drop the presser foot while pulling thread, thread should get tighter, then thread needle and machine will work fine. Make sure the top tension is set at where you normally have it, probably about #4 or #5

Double check that your needle is the proper one for your machine, and that it is in properly. It sounds like it is not picking up the thread properly. Tension problems usually have more to do with threading, thread or needle problems than with bobbin problems. Also check your bobbin is unwinding in the proper direction for your machine. Most machines unwind the bobbin thread, turning clockwise. Set your screw back to the factory settings, and give the machine a good cleaning as well. Lint can cause this to happen as well, if it builds up enough to interfere with the needle and the hook action. Double check that your upper thread is threaded properly as well. I suspect your needle is in backwards however.

If the thread under the fabric is loose you need to tighten the upper tension. If it's on 4, bring it to 5. If it's on 5, bring it to six and continue doing that and sewing till its perfect. You may need to decrease your lower tension if you can't get it just right.

Bernina Sewing Machine Parts

Make sure the presser foot bar is UP before you thread the machine, otherwise the thread doesn't connect propertly with the tension discs. Top thread should reel-off in clockwise direction.

I'm assuming the thread is looping on the bottom. If this is not the case, ignore the rest of this.
Perform a tension test. 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