Hi there, I recently started using clear monofilament and trilobal polyester threads for some of my projects. Right now I'm trying to free motion quilt with invisible thread on top and poly on the bottom. Every few inches I seem to get a loop of the invisible thread pulled under to the bottom, causing my motion to sort of "stick". If I press the fabric to keep going I end up breaking a needle or at the least the monofilament thread. I slowed it down to see exactly what is happening, and it seems a loop of clear thread is pulled down into the bobbin area and catching (I have a drop in bobbin). I have lowered the tension to around a 4 and am using a size 14 needle. I tried using the invisible thread with regular 50 weight cotton on the bottom but have the same problem. I have a similar issue when I use poly on the top and bottom together, but if I use poly on TOP and invisible on the BOTTOM I don't have the problem anymore! Lol* I don't seem to have any issues when using 50 wt. cotton on both the top and bottom either. I have changed the needle several times and adjusted my tension all over the place and still am having issues.

Does this sound like a timing issue? Tension? Any idea what I'm doing wrong? I have a back up sewing machine and was going to test out the thread combination on that one but cannot find my powercord and foot petal! Lol*

You need to be very careful with how Monfilament thread comes off the spool. It'll twist into a knot and cause the situation you are encountering. You may need to use a side mounted thread holder.

You can also get thread socks. They go over the spool and help keep the thread from tangling when it comes off the spool. You can also get a pair of knee hi's and cut one just big enough to put over the spool and it does just as well. It didn't take care of the problem completely, but did cut down on the number of times it happened to me. Hope this helps.

mytwopals - thank you for your quick reply...maybe that is the problem, I will test it out. I haven't seen a knot just looping under the quilt...unless that's what's causing the looping. I sort of thought it might be tension...as if the bottom tension is pulling the top thread to the bottom excessively...but it doesn't do it with every stitch, maybe every 3-4 inches.

Oh, now I know. I thought you were suppose to have the invisible thread in the bobbin as well as on top.

Can you not use them seperately?

That is an idea, thank you so much for the suggestion!

that thread requires less tension, a net over the spool &
spool off the machine and to back right

Ok, I went back and am watching very carefully - it's not knotting up at the top it's down below underneath the fabric. Just one loop. Sometimes that loop gets pulled down into the boobin area and gets stuck around the bobbin tension.

I hate invisible thread and it obviously hates me. It is just a lesson in futility for me and I stay away from it. Good Luck! I've never had any luck machine quilting with it.