Brother pe770 bobbin thread is showing on top of fabric.

Yes Adjust to more tight see what it'll do.
Bottom bobby is too tight or upper thread control is too lose.

Good luck

Mai

Am having a difficult time picturing this. Sounds like the upper thread is creating loops under the fabric and the bobbin thread is showing on the top of the fabric.

Make sure to use a brand new needle.

Remove the thread from the machine
ALWAYS raise the presser foot and rethread the upper thread.
Make sure the thread path is correct.

Check that the bobbin is turning the correct direction in the bobbin case and the bobbin thread is threaded through the bobbin tension correctly.

Set the upper tension to the midway point (factory standard), however, this setting may need to be tweaked for your particular machine.

Bring the bobbin to the top of the project Before beginning to stitch.
How and Why to Bring up the Bobbin Thread

Retest--begin sewing slowly.

If the upper thread is still showing on the other side of the fabric, the tension is too loose. If it is pulling the bobbin thread up to the top of the fabric, the upper tension is too tight

OR the bobbin thread tension is too loose. (CAUTION: make only small adjustments to bobbin tension--1/8 of a turn at a time!!! It also helps to mark the screw groove location with magic marker on the bobbin case BEFORE making any changes so you can back it out and return to the original setting.)

Bobbin Tension How and Why Tension is Adjusted

Understanding Bobbin Tension

Understanding Thread Tension Threads

Sewing Lesson 10 How to Fix Tension on Your Sewing Machine

...

Usually, if there are loose threads under the fabric, it is the top thread that is too loose. Check your sewing sample closely--you can even test with two different color threads to help distinguish which thread is which. Loose top thread will generally be pulled DOWN and show under the fabric. Loose bobbin thread will be pulled UP and show on the top of the fabric. The ideal tension is when both threads MEET in the middle of the fabric.

First, remove the thread from the machine. Install a brand new needle. Always Raise the Presser Foot and thread the upper thread, making certain the thread path is correct.

Check that the bobbin thread is threaded correctly and turning the proper direction in the bobbin case.

Set the upper tension to the midway point and sew a retest. A tweaking of upper tension may be necessary to get it where it should be. Generally, upper tension should make the majority of adjustments needed for tension correction. Bobbin tension is one of the last tension adjustments to make as it is very sensitive and can go awry very quickly.

If, in fact, the bobbin tension is off, the tension skrew on the bobbin case is where the adjustment is made. Before making any bobbin tension adjustments, mark where the skrew slot is located on the bobbin case with a permanent marker. This will allow you to reverse your changes if necessary. Be CAREFUL as TINY changes make HUGE differences in tension. Make only 1/8th turn adjustment, then retest before making another adjustment.

Remember that tension testing and readjustment are a necessity when sewing. The same tension that will work with light weight thread and fine fabric will most likely not work when using heavy thread on drapery fabric. Get comfortable with making tension adjustments to get the ideal tension for each project.

Understanding Thread Tension Threads

Oh You Crafty Gal Sewing Lesson 10 How to Fix Tension on Your Sewing...

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=14&ved=0ahUKEwilg-3t2vHMAhVJDlIKHXnsBWYQFgheMA0&url=http%3A%2F%2Fwww.ca.uky.edu%2FHES%2Ffcs%2FFACTSHTS%2FCT-MMB-213.pdf&usg=AFQjCNE4QlGk1Fvt8K2UGCRCfzMpGS-A2Q&cad=rja

How to Adjust the Tension on Sewing Machine

...

if your saying that your bobbin thread is balling up under the platen plate , this is a sure sign that your top thread tension is not correct and there isn't enough tension to pull the bobbin thread up from below

Factory standard tension for upper thread is the midway point between the high and low number. However, that tension dial is meant to be used for tweaking tension. Generally, tweaking is required whenever the type of fabric, needle, or thread are changed, ie thicker fabric like denim should have a different upper tension setting than fine chiffon. To be successful with tension settings, one must become comfortable adjusting the upper tension.

NOTE: Accurate tension is achieved when the upper thread and bobbin thread meet in the middle of the fabric.
.
Understanding Bobbin Tension


...

Try loosening the tension for that bobbin

bottom thread is loose, tighten the tensioner in the bobbin, (you might have to loosen the top to balance.) make sure thread was properly routed.


threading of bobbin sewing machine pictures Google Search

Shelia,

when sewing these parts of the design, (small stitches? ) load your bobbin with the same top thread. Just match the top thread color, and done! No more white bobbin thread in the topside of your designs.

Cheers,
Kelly
Embroidery Services
San Diego, CA

Loops appear on the surface (top side) of the fabric?
Reduce the tension by turning the upper tension control dial to a lower number. If the loops still appear on the surface of the fabric after you adjust the upper tension, the bobbin thread may be too loose. In this case, turn the screw clockwise, being careful not to over-tighten the screw, approximately 30-45 degrees to increase bobbin tension. After you adjust the bobbin thread, adjust the upper thread to match the bobbin thread.
Make sure you reset before your next project.

loosen your top tension.