Elna SU missing stiches and breaking thread

It might be here

https://www.google.com/search?q=Elna+Air+Electronic+SU+bobbin+replacement

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The tension dial is on the front of the machine right above the needle. The higher the number, the tighter the tension is applied to the top thread. HINT: When threading the top thread, ALWAYS RAISE the presser foot throughout the entire threading process. This allows the thread to seat completely in the tension disk. Tension is correct when the top and bobbin threads meet in the middle of the fabric.

Elna Lotus Instruction Booklet

Elna Lotus SP bobbin case repair Removing cotton jam from Elna Sewing...

Elna SP ST SU sewing machine repair tips (I use liquid Tri-Flow Synthetic Lube or silicone spray to loosen parts seized from old oil. Do NOT use WD-40, cooking oil, motor oil...)

Hi. Try this site to look at a free online manual.

https://www.manualslib.com/products/Elna-Su-2614738.html

I hope this helps!

Hey I can help you with this, its a long detailed explanation though. Have you removed the bobbin holden, ie,undone two small screws and lifted out the silver bobbin case, leaving a black round thing? This black bit is the lower ring guard, you have probably undone this to remove a thread caught in the edge of the bobbin case or umderneath. Elna manuals never detailed cleaning here but it is simple enough and needs doing from time to time, i have seen big wads of felted threads and lint under guard rings when pulling apart machines. This video shows how to line up the lower guard ring, the outer casing and the bobbin case.

Elna Lotus SP bobbin case repair Removing cotton jam from Elna Sewing...

I always turn the flywheel until the opening of the lower casing is facing forward, then look at the black lower guard ring and turn it until the cut out bit is facing the front. Now look a the bobbin case, it has a couple of silver Beaks and these need to fit in between the stoppers on the outer case. You will know if lined up right as it just fits straight in, wiggle a bit left or right until its lined up. Those two silver screws have to marry up with the two holes in the lower guard ring.
Once aligned , tighten up the two screws until firm. There is a dark coloured screw too, leave it alone.

Hope,is helps, once youve done this a couple of times, its easy.

is the belt slipping now? You'll probably need to take off the top cover and see if you can clean up the spilt lubricant off the bobbin winder mechanisim and the drive belt on the right of this. The bobbin winder is friction driven, a rubber ring around a plastic barrel and when you click this over to the right the rubber ring drives off the main drive part of the machine.

removing the top panel is a bit tricky because you've got the handle there too, two screws unscrew it, then you need to manouvere the cover upwards and left to get it out of the bobbin feed part then tip it to the back of the machine to give you a view of the inners. You might want to subscribe to the Yahoo group called "Elna Heirlooms" as there's probably a prior thread on this there, lots of Swiss Elna owners who service their own machines, very useful place to visit.

not unless you can find another swiss elna, like star series su. check bobbin in right way, holes on top to wind and load. you havent bought anothet type bobbin??? go to www.arizonaexpressionz.com and download a manual for supermatic. then read bobbin winding and threading carefully and rewinf bobbin and thread up again. make sure thread goes into tension spring all the way. bobbin should turn anticlockwise when yoou pull thread. also please brush clean bobbin holder area and check for any threads caught there. now a drop of quality clear machine oil in middle hole and gently run for 30secs to work in. do this every time you get your machine out. there are several oiling points shown in manual. oil them. these machines are quality but yours may need love tlc from a elna tech especially if it has not been serviced in a while. but a well maintained elna will out stitch a new plastic machine any day in my humble opinion. if you want to join yahoo group elna heirlooms, experts who service their own and share photos info manuals and love these vintage classics.

Hi! Congratulations on your old Elna! I just love old sewing machines; they are so solid and reliable.

(Unless of course you're getting a big bird's nest with the bobbin thread, right? That's so frustrating!)

With my old machines, I've found that a tiny bit of thread caught in the bobbin assembly can cause these nasty tangles. I use a bright flashlight and a pair of tweezers and just keep looking until I find it. While you're in there, clean out any old lint or gunk (meaning, old oil) you find. Brush all the lint out. I use a q-tip moistened with a bit of WD-40 to clean the gunk (but be careful that the fuzz from the q-tip doesn't come off while you're cleaning). With the WD-40, you have to be very careful not to get any of it on the surface of the machine--it can mess up some of those beautiful old finishes.

So clean the bobbin area, make sure you're threading the bobbin correctly, and lastly, if you hold the tails of the top and bobbin threads snugly in your left hand behind the needle while you take the first few stitches, the birds' nests should be a thing of the past.

Let me know if this works, ok?

Happy Sewing!

Please describe the type of bobbin you have. Is it held inside of a removable metal casing? Or is it a dropin type? Is the sewing machine what is known as a "freearm" which you can put a sleeve or trouserleg over or is it a flatbed type? When I know this I can help you further.(I used to sell sewing machines).

I have a 26 year old Elna and this is the only weakness it has. Before sewing, try this. Turn the wheel manually and watch the upper thread pick up the bobbin thread. Pull both back to the left. Make sure they are plenty long. This helps me prevent the tangling in the dogfeed. My Elna has a universal tension on the bottom and I haven't ever had a problem with it unless the top tension is too tight.