HELP with sewing machine messing up!
 

I was sewing right along and noticed my top (upper) stitch was fine but the lower had almost a loopy design to it almost like a rounded zig-zag pattern. I did not touch any of the tensions. The only thing was re-loading the bobbin. I noticed that the thread may jump out of the tension adjusting spring. I have a Brother XL 3500 i. This is what I hate about sewing!!!
Any suggestions? Thanks!

Turn the machine off then back on ... and rethread all of the threads including the bobbin. Check your tension settings the upper is typically set between 3 or 4 .

Try changing the bobbin. This happened recently to me. As soon as I put a different new bobbin it worked fine.

I was always told, when anything messes up, first, re-thread, that takes care of most problems. Especially if it was fine before.

I was wondering if the type of thread is part of the problem, its a new spool of Coats topstitching. I was doing fine until the bobbin ran out and I put the new on.

Don't you hate when that happens?? Ughhhhhh

Clean the bobbin area, rethread top and bottom, try a new needle (my Brother always played up when the needle needed changing) also make sure that your feeddogs are up and your presser foot is down. Hope it starts to behave itself, very frustrating when your machine is being naughty.

1. Rethread the machine.
2. Take out the bobbin and put it back in.
3. Change the bobbin.
4. Change the needle.
Most of the time one of these will fix just about any problem.

You had the topstitching thread in the bobbin? That is usually for heavy weight fabrics. That thread is too thick to have in the bobbin for regular sewing. With it being on the top you need a very thin thread in the bobbin at least a 50wt 2 ply.

BellaBoo, that was my first thought, too. The thread is probably too thick for the bobbin tension spring.