Necchi 575FA how to put the bobbin spool in the case?Bobbin mats up with a lot of threads on the bottom stich.

SOURCE: bobbin thread not catching

Whenever you see loops on the underside of the fabric something is snagging the thread. the biggest culprit is burrs on the hook. the hook is what goes round and around the bobbin. The reason for burrs on the tip of the hook areseveral

ONE ...is by helping the fabric through as the machine is doing the sewing which directs the needle too close to the hook thus scarring the smooth surface of the hook and potentially breaking it off and the needle too. You must allow the machine do it on its own and only guide the material.

TWO...Sometimes if you are sewing s-t-r-e-t-c-h-y double knit material the material calls for a ball point needle. I have gotten good results with the Singer brand YELLOW BAND needle.

Three ... The hook could have gotten out of timing. What this means is that the hook is not meeting the needle on the top edge of the eye of the needle. You yourself can check this out by removing the bobbin (or shuttle, cassette). Install the needle flat side to flat side of the mounting rod and all the way up. By slowly turning the handwheel on the right slowly and watching that the eye of the needle is just below the hook on the upward swing of the needle and that they both meet dead center. This when you need to take it in to a repairman. FrankIy I don't like to advise this because of unscruppulous practices. My boss used to call me a virgin Mary because I wouldn't ripp-off the customers. Anyway at this time you can also check the condition of the hook carefully looking for nicks and scratches on or around the tip of the hook. If there is damage present you can file this down with a very fine emory board or by using a strip of 400 to 600 grit sandpaper as if your were buffing a shoe. If the hook is removeable by unsnapping the snaps on either side its easier to buff. Anything courser may contibute to the problem. If the paper won't remove the damage you may need a whole new hook. If its not removeable you will have to take it in to have it installed.They have to time it properly.

Four...The two disk that you mentioned also has a spring. That sping is there to pull up those loops. If the disks are full of lint from the thread going through. the clups of lint won't allow the discs to apply tension on the thread and thereby having tightened the tension so much that that spring is not working properly.You can clean the discs by raising the foot which opens the discs. With a long narrow pick pull out all that lint without scatching the discs. Check closely that the the thread goes across the top of the machine down through the discs pull up snug so the spring engages,through the take up arm,in the two thead guides, then into the needle front to back or right to left, if it is a side loading bobbin. Now the tension will work properly!

TESTING : Move the TENSION dial to mid point of the dial usually 5. This is your starting point.
With two layers of fabric ( not stretchy) and with a regular needle, set stitch length at about 12 per inch on the dial. Now sew about six inches. Raise the fabric and look at the results. Do minor adjustments necessary on your tension dial up 6...7.. if loose on the bottom 4...3..2 if loose on top.
If you did all the steps above those are the steps a repairman performs and charges $75 except me I used to charge $10 .

Brother machines are good quality it is those hidden gremlins that make a fun hobby frustrating when you don't have someone to turn to without having to shell out cash! Its been a pleasure!

jravenus

SOURCE: Elna SU missing stiches and breaking thread

it sounds like the needle hook timing is out. You need to get the needle in the lowest position and measure the gap from the needle to the hook point on the bobbin shuttle. It should be 1/4". You will need to remove the foot and foot plate to be able to see. I use a 1/4" drill bit as a gauge. If you need to adjust it, you will need to remove the free arm cover to the right of the foot and loosen the 2 allen head screws that hold the drive gear. Adjust the gap, tighten the screws and retry. Usually if the needle catches the thread to early, it will make a bad stitch and the upper thread will break. If it catches to late, it will make thread loops and the machine will skip stitches. Good luck, these are a good machine and worth fixing. Phil

SOURCE: Upper thread knots up with bobbin thread when sewing a stich

Thread test
Test your thread quality to start, thread your machine and LIFT the presser foot (this opens the tension disks). Pull your top thread straight back. If you feel no tension no mater how much thread you pull, your thread is good. If that your machine passes that test, then let me know, we can go to step 2. If not, try different spool of thread, same test until you get a smooth pull (tip: always check your thread this way when you thread your machine)
Step 2:
Pull on your threaded bobbin thread while it’s in the machine. Does it pull smooth and even? If so, go to step 3. If not, try a new bobbin (bobbins get bent or distorted if wound too tight).
Clean thoroughly in the hook and bobbin case area and oil 1-2 drop is all.
Thread knotting on the bobbin can be a lot of things but here's some guidance:
Tension:
If the thread is loose on the bottom of the fabric, it's actually the top thread is too loose. Think of 2 little elves playing tug of war in your machine, one on toip and one underneath. If you have loops on bottom, the top needs to pull harder (tighten top tension)
Jamming bobbin case:
If it is damaged from turning out of place once, it could have rough spots on it that makes the thread hang on it, and keeps making it turn over and over. Use a finger nail board (fine sanding) and smoothall rough spots. Then reset the bobbin case taking care to put the notch in the bobbin case in alignment with the proper spot in the machine (basically 5 o’clock) when looking at the round area where the bobbin case goes.

SOURCE: thread knotting around bobbin case

hello, I had the exact same problem and could not find the solution until i took my machine to my sewing sensei and i solved my tedious problem. It was actually not a tension problem at all but a threading problem. Make sure you have threaded your bobbin correctly and that when you pull on the bobbin thread that the bobbin turns the right way. (mine must spin anti clockwise to work)  Make sure that when you pull up the bobbin thread using the needle that it is not over the feed dogs connective bar but under it. A big problem when the thread gets caught around the bobbin case wheel is that the thread is looped around the feed dogs once and that causes the thread to get caught around the bobbin wheel. In conclusion, thread the bobbin correctly and read over your instruction book before spending the money to get it fixe in s shop.

SOURCE: bobbin case is disassembled. how do I put it back together?

It should be in your manual.... but if you don't have one, I'm gonna try this out. I don't know the official names, so bear with me.



There should be two plastic arm-lookin things that are turnable. Make sure these are turned outwards.




You should have three silver pieces. The one you need first is a half-moon looking thing with a knob comin out of the middle. (it also has some holes in it)



If you turn the big knob on the right hand side, there should be a moving piece on the inside of the bobbin case.



The half moon needs to fit in with that piece. Don't force anything cause we don't want the machine to break. >< The knob thing needs to be facing the outside, otherwise it's not gonna go in at all.



Once you get the half-moon thing in there, you have two more left. There's a big circle. WOO! CIRCLES! ANYWHO, The big silvery circle.. it has a knotch in it, and a little pokey-outie thing comin' out of it.



It needs to be positioned so that the knotch (on the inside of the circle) is up and the pokey-outie piece (on the outer side of the circle) is on the bottom. On your machine, there should be a place where the pokey-outie piece would fit perfectly into a little hole-type-thing. Put it in. :O



Now it's time to move those little black plastic arms towards the center. On your circle, there should be little grooves that they fit right on top of. ^_^



The only silver piece left should be the actual bobbin case deal. This should be a smaller circle with a movable arm and a silver thing pokin' out of it. (I told you, I'm bad at names!) Before you put this guy in, we need to have your plastic bobbin threaded. (I'm assuming this has already been done, correct me if I'm wrong.... they also have pre-threaded bobbins for sale, but hey, whatever works.)



Your bobbin needs to fit inside this last piece. (my first bobbin didn't, and I freaked out and ran to my dad... LOL) You need to make sure there is a trail of thread coming out of your bobbin that's about two to three inches long. Place your bobbin in the silver guy and there /should/ be a little niche where you can play with the thread and pull it through the silver guy's parts. (Your thread may break, don't worry, just try again)



When you move the thread around, it should come out where the little arm that sticks out is. Keep the 2-3 inch trail goin' on, you'll need it. Remember that first half-moon silver guy? Well, we're gonna stick our little assembly onto his pokey-outie piece.



The silver arm-thing on our assembly needs to go into the knotch that's in our circle, and push in so it clicks. (Sometimes mine clicks twice...) Make sure you have that trail of thread, and go ahead and flip the white plastic up, because you're DONE assembling it.



I'm going to assume you have your top thread in already (again, correct me if I'm wrong..) make sure that your top thread is through the hole in the needle, otherwise we're thoroughly screwed. Pull that thread until you have another 2-3 inch tail, and twist the big white knob on the right side of your machine (same one as before...) TOWARDS you. KEEP HOLDING your top thread, otherwise it'll disappear into the abyss that is your bobbin assembly.



When you turn the knob towards you, your needle should dip down into the abyss and come back up- with your bottom thread! HUZZAH! it SHOULD be a loop around your top thread. (I'd use contrasting colors for practice.. so you know what it'll look like)



The manual says to "grab the bottom thread" but seriously, I can't get me fingers down in there, so I just slide some scissors under the foot and between the two sides of the loop, and just slide 'em left. usually works just fine. Unless my tail for the bottom thread is too short, cause then it'll be hard to grab. You should be good to go!



I know this is pic heavy and kind of long, but I like to provide as much info as possible! Let me know if it helped!!