Tension on brother se1800 sewing machine isn't working right. Top thread appears on back of fabric, So far I've checked threading top and bobbin, cleaned race.

So, it sounds like the bobbin thread is coming to the top of the fabric and the top thread simply lays on top of the fabric. Just a hint: If the thread problem appears on top of the fabric, it is usually a bobbin thread problem. If the thread problem appears under the fabric, it is a top thread problem.

Is the top thread tight, ie pulling the bobbin thread up? Try loosening the top tension.

If that doesn't resolve the problem, then you probably need to tighten the bobbin tension.

Understanding Thread Tension on Your Sewing Machine

Hi, I do hope this link will help you, it shows a step by step process with pictures to assist you further, I do hope this helps....

http://support.brother.com/g/b/sp/faqend.aspx?c=us_ot&lang=en&prod=hf_xr1300eus&faqid=faqh00100034_005

Check your stitch sample. Dollars to donuts it's the top thread bird nesting (also called thread nesting) under the fabric. Issues appearing under the fabric is usually top thread related. Problems appearing on the top of the fabric is usually bobbin thread related.

Remove the top thread from your machine.
Be sure to start with a brand new needle.
ALWAYS RAISE the presser foot and rethread the top.

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Your stitches may be too far apart. But, most likely the issue is that the tensions are not correct. If one thread lays in a smooth straight line on the fabric, the other thread tension is too loose, ie the bobbin thread lays on the fabric and the top thread is going all the way through the fabric and shows on the bobbin side, then the top tension needs to be tightened. The tensions are correct when both threads meet in the middle of the fabric.

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

try changing the needle first--make sure the needle is the correct one for the fabric being sewed.
if you've adjusted the top tension & the bottom stitch still looks the same
it's possible that the top tension dial is needing to be checked to see if it's
working correctly

if you've taking the machine in 4 times to be fixed,,sounds like you need a different sewing machine repair shop.
have you tried changing needles?
have you tried rethread the top & bobbin thread
is it possible the bobbin thread in not correctly inserted in the bobbin case?
try a top thread tension of 5 & see what happens?

Does it sew okay on a single or double layer as this sounds like the threading up is not correct to me. The grinding may be that the bobbin case isn't in correctly.

However, best way to diagnose is to start fresh, take off the thread, remove the bobbin case, clean out the rotary hook (under the needle plate) clean the feed dogs and remove the needle. Clean the tension discs too (turn to zero and floss between the metal discs with selvage edge of a clean piece of cotton scrap fabric, until its clean, no gunk coming out). Turn tension dial back to 4 or 5, your normal setting.

Now wind a fresh bobbin making sure it winds nice and smoothly, keep tension onto the thread spool to achieve this and watch as the thread goes onto the bobbin, give it a nudge so it fills the bobbin smoothly across the whole core, top, middle and bottom.

Now put bobbin into bobbin case and ensure it goes into the tension spring correctly. I can't see an image of your machine to know if it is top loading or front loading bobbin, sorry. But refer to your manual to ensure you get the thread fully into the tension device. With a front loading bobbin, there is a removable bobbin case. Ensure that this is holding the thread with enough tension, if you suspend the bobbin and bobbin case and just hold the thread tail there should be enough tension on the thread that the case just hangs, but if you give it a litle jolt, it should release some thread. Adjust the tension spring with a little screw on it in 1/4 turn increments until you get it to this point.
Try this link for some images and trouble shooting help on bobbin case. http://www.sewusa.com/Sewing_Machine_Repair/Thread_Tension_Settings.htm
If you can't get the tension right on the bobbin case at all, then take it to the Brother shop and buy a replacment one, sometimes the springs do fail on them.

Now put in a new needle and make sure you have used the right size needle for your fabric, ie medium weight woven you need a size 80 universal, but if it is a knit fabric like jersey you need a ballpoint 70 or "stretch 70" if its got a lot of lycra in it.

Now thread up the top thread and pay careful attention to getting the thread into all the thread eyes, particularly the take up lever and make sure it goes into the top tension discs fully (always thread with the pressure foot raised so the tension device is open). Lower the pressure foot and pull the thread just before the needle, it should feel very firm if the top tension is working right. If there is no resistance there, you've got a dodgy tension dial, take it for service/replacment.

Continue threading to the needle, bring bottom thread up to the top by turning the flywheel through one cycle towards you. Now hold both threads together at the back and test stitch a seam.

If you are still getting the noise from it and thread jamming up underside then the fault may be more timing related in which case you'll need to take it to a sewing machine technician too.

You need to tighten the tension on the bobbin thread as it is too loose and is being pulled through by the tension on the top which is probably correct. First check that the bobbin is in correct. I know it's frustrating but even after 40 yr it's where I start if it's all in right then tighten the screw on the bobbin case a little at a time till you get it to the right tension. The thread coming out of the bobbin case should take a pull for thread to come out if you hold the thread and turn loose of the bobbin case and the thread unwinds like a yo-yo it's to loose. The bobbin should stay in the case wile you test it this way.

Your bobbin is probably too loose. When you set a new bobbin, stop every now and then and try with your fingers nail if it's nice and tight enough. Not extremely tight, but tight, not loose and moves easily when you set your finger between the threads.

With most fabrics (99%) the plate is fine at the the top position, just with very thick and "fragile" (satins etc) you might need to adjust it.

Settings: Tightest tension for the thinnest materials, more loose for the thicker ones, better have a test piece, it rarely goes under 5 anyway.