bobbin spinning in long arm
 

Does anyone know what causes a bobbin to spin in the case on a long arm? Just brought it home from the shop had it serviced and adjusted (250 miles round trip x 2) & now the bobbin is spinning and bobbin thread breaking. Oh, & I have a Bobbin Genie in the case. Has anyone had this problem or know of a fix? I tightened the screw just a smidgen & was able to finish but I think the thread broke one more time after that. This is a new problem to me.

You don't say which brand of Longarm you have ...HQ..gammil...apqs ...the company could help you with the problem...I have an APQS and they are great ...I have read info on this problem...I read it happens less with the L smaller bobbins as opposed to M larger size...but not sure if it's in fact true...I have L bobbin...do not have this problem...

i also use a TOWA gage to help adjust tension for breakage...and I wind my own bobbins...I prefer them to the prewounds...

It's call backlashing. First check that the bobbin tension is acceptable. There are youtube tutes for this. If all seems ok, the problem is a loose bobbin. You can purchase thin plastic washers to insert into the casing before setting the bobbin in, but I just cut a small round bit of cotton fabric & put a hole in the middle, and set it in well. Have only had to do it once and no more problems.

Thanks, I did tighten the screw on the case & I have Bobbin Genie's inside the case but it's happening on several bobbins what I filled plus the bobbins are the same ones I've used for several years that were ordered from Tin Lizzie specific for this machine. Maybe the machines tired, the thread didn't start breaking till I was nearly finished with this quilt. Maybe it was telling me to just quit not quilt
. lol

Here's another answer

If your bobbin is spinning faster than you can stitch, remove the check (backlash) spring from the bobbin and pry the two fingers out a bit. Reinsert and do some stitching off-quilt to see if that helps. Bending the fingers out will prevent bird's-nests and breakage by stopping the bobbin when you stop stitching. You'll need to adjust your bobbin tension after this fix as it will be tighter.

I am wondering if the tech removed the antibacklash spring when servicing and forgot to put it back in? They pop out very easily but I don't know if normal servicing would mandate removal of the antibacklash spring from the bobbin case. Additionally I believe a magic genie bobbin washer would cover up the antibacklash spring and defeat the purpose of it. I don't think you are supposed to use both at the same time but I could be wrong. I do know you have to remove the antibacklash spring when using magnaglide bobbins. I have only had backlash on a few occasions and that was when using the cardboard prewounds, like the ones Superior sells. I rarely use them anymore.

I pretty much use magnaglide prewound bobbins exclusively and never have a problem with backlash and rarely have issues with tension. To me they are well worth the extra expense.

I have a Gammill and it has a "backlash spring". So if the problem is backlashing as Gay said, this could be the problem. Check to see if the backlash spring has broken or is inserted wrong and check your manual.

Sometimes the anti backlash spring needs replaced, too. It's also possible the tech took it out then wasn't careful reinserting it and bent it. You know how you have to carefully slide of of the "ears" into the slot then arc the spring so the ear on the opposite side can slide into it's slot? I always do it with a pair of bent tweezers, very carefully.

Ok, I don't know what you all are calling the backlash spring, is that the little coil on the front of the bobbin. & when the bobbin thread breaks & I take it out the bobbin has spun until it has several loose loops of thread around it. I don't always put my thread through the coil, should I be using it? It's not spinning because I've stopped stitching, the bobbin thread is breaking & I'm using polyester thread which should be stronger than cotton. Or maybe the check (backlash) spring is the one that wraps the case, it adjusts with the screw, & the thread goes under it. oh, I'm so confused.

The backlash spring is inside your bobbin case, I would think you'd know if it weren't there but possibly not. I know I dropped my bobbin case and the spring got damaged I wound up buying a new one but managed to fix the first one so now I have a reserve one. I hope you get this sorted it's so annoying when something happens after you've had it in the shop. I would call the manufacturer but I would start with the person who worked on the machine.