Loose bottom stitch on brother se 350

Have you tried adjusting the bobbin tension? There's a small screw on the bobbin case so the bobbin can be adjusted. only turn the screw a little at a time. Also be sure your top tension isok. However if you still need help these days you can buy a new bobbin case and a new top tension, both will be adjusted already to use from the factory. don't let it drive you crazy they sell the preadjusted parts for us few that just want to sew not be a tech to just sew a blouse etc. I hope this helps. good luck
Lynn

Remove the thread from the machine. ALWAYS RAISE the presser foot and rethread the machine from the beginning. Verify the path is correct. The standard tension setting is the midway point although you will most likely need to tweak this for your particular machine.

If you are still having problems, you may need to readjust the bobbin tension.


Understanding Thread Tension Threads

1 - Make 100% sure you are threading the top thread correctly.
2 - Make sure your top tension is set at 5.
3 - Look in your book and make sure you have the black plastic bobbin case inserted 100% correctly.
4 - Remove the black plastic bobbin case and inspect it for burrs or needle damage, if so it needs to be replaced.

Clean the machine, especially the bobbin and bobbin case area and around the feed dogs. Take all the thread off the top of the machine, including thread off the spool pin. Raise the presser foot. Rethread the top with the presser foot UP, which lets the thread get between the two tension disks. Put the foot down to sew, and hold the ends of the bobbin and top threads together behind the presser foot for the first 2-3 stitches in each seam.

See also: http://www.picturetrail.com/sfx/album/view/22521551 I'm betting you're seeing something like the last two pairs of photos.

have you tried to tighten the bobbin tension spring??

Looping or bunching on on the bottom is a result of problems with the TOP TENSION.
Rethread the upper thread and adjust tension. Try again.

try to rethread the machine all the way back to the spool of thread and check the top and bottom tensions on scrap of same fabric

the tension is wronge has the lower bobbin case been unwound and refilled)(check that this is threaded right as well)

You don't want to adjust the bobbin tension, you'll want to try adjusting your stitch length, as well as the regulator tension.

I just posted this under another Brother machine...mine is a se 350 but, might be the same problem!! Hi....I also kept getting the check and rethread upper thread message, I'd sew about 15 stitches and it'd stop. Here's what I did. On the left of the machine, in the back there is a screw....loosen that screw, take cover off, then lift straigt up and out on the cover that has the 3 on it in your threading seqence. Next, I started inspecting and cleaning the thread route from top to bottom. Lo and behold....I get to the place where you come down the front of the machine and turn to go back up and I spot a little slice/cut in the plastic piece so, when I was threading the machine I guess I was pulling it to far to the left causing it to wear a little slice/cut in that piece....so, I finished cutting it off with a utility knife, used an emery board to smooth it down, put the covers back on and it works GREAT!!!! Who would've ever thought that it'd be so easy and save me a bunch of money!!! I sure hope this helps someone.