I am trying to learn to FMQ on my Grand quilter and am having a problem with the top thread separating and the outside sliding back on the thread at the needle. What am I doing wrong-----have changed needle, rethreaded,----I am using dual duty machine quilting thread.....

Try a different brand of thread.

check needle and change again is your top tension too tight

Thanks, I will try all suggestions.

The machine may be threaded wrong. Take it out and do it again with different thread and test it. Hope this board can help you.

Are you referring to Coats & Clarks "Dual Duty" quilting thread? I've had the same problem with that thread. Other threads work fine.

sounds like you are using the wrong size /type of needle for your thread. if the needle eye is too small or shaped wrong for the thread you are using it will fray- break the thread.