I FMQ with a Designer I also. What size needle are you using? I have found a top stitch needle works well. I have also had success with a metallica needle. this is a needle designed for metallic thread and it has an extra large scarf. This protects the thread more and minimizes raveling. the thread actually goes thru the fabric several times before it's actually incorporated into a stitch, which is why fabric and batting can play a role in thread problems.