Tension Trouble Only in Certain Directions -- What Should I Tweak?

[Rebecca Grace]

I know that a long arm machine is never going to stitch identically in all directions, but I've been seeing drastically different stitching in a ruler work border that I was stitching yesterday and it's making me nuts.  What can I tweak to improve this?

This is quilt shop fabric top and bottom (both from Free Spirit Fabrics), Quilter's Dream Cotton Select batting, new 3.5 needle, So Fine #50 in the needle and Bottom Line in the bobbin.  Bobbin case tension was adjusted to Superior's recommendation for Bottom Line using a TOWA gauge, then adjusted top tension per Jamie Wallen's method (so you see the bobbin thread pulled to the top, and then back off slightly until the bobbin is just barely visible through the needle holes so you know it's going to settle inside the quilt sandwich).  I'm doing ruler work so I'm running the machine fairly slowly, and have tried slowing down even more (in case this is a needle flex issue) but it doesn't seem to make a difference.  The stitches look great in both directions on the back of the quilt but if I try to solve the flat line stitching by lowering my top tension, then the opposite line of stitching gets messed up.  I have also tried loosening my quilt on the frame.  

I know I've heard mention on this board of inserting the needle turned slightly to the left or right rather than dead centered.  Would that help with this issue, and if so, which way should I tweak my needle -- to the right or to the left?  What else might help?  

[Cagey]

Cheeky,

Turning your needle could not cause any harm.  Are your flat lines when you quilt from the bottom left of the picture to the top right?

If so, could it be that you are placing slightly different pressure on your ruler/ruler base that could be causing the needle to be pulled slightly away from the hook?

Nigel had suggested in an earlier post to this same type of question to set up a camera to capture your thread path and quilt sandwich to help find the cause of your tension issue.  This too would not hurt to help find a solution.

As the tension is fairly constant the entire line stitch, once you find the problem it should be fairly easy to correct.  

Cagey

[Frangipani]

I just had a similar issue using Glide 60 wt on top and in prewound magna-glide bobbins. Lucey skipped stitches and shredded the thread but only when going away from me, especially lower right to upper left. APQS helped me troubleshoot and it did get better, although not perfect. They had me change my thread path through the three-hole tensioners slightly. Here is a photo showing the thread path through them...hopefully you can zoom in. I also rotated my needle slightly to the left (at about 6:35 on the clock). I did some reading in the forum and saw that sewers aid lubricant was suggested to help this. I purchased some and dripped it onto the top edges of the thread cone to lubricate the thread, which seemed to really help. Let us know what you find! 

[jimerickson]

Turning you needle will help with skipped stitches, but not with tension issues.  If you're using equal ruler tension in all directions, then I think it's a matter of tension adjustment.  The direction you are sewing affects stitch tension by drag on the  top thread. e.g. more tension in some directions, less tension in others.  With very light tension the direction tension variables become magnified.  My suggestion:  Tighten your bobbin tension to 200 on you TOWA, then tighten your top tension enough to balance your stitches.  With this tighter stitch, the direction tension differences will be a much smaller percent of total tension, and stitch balance will be easier to achieve.  Jim   

[Cagey]

Jim,

You explanation on the tension magnification makes perfect sense.  Thank you for sharing.  

Cagey

[Rebecca Grace]

Oh my gosh, Jim, thank you SO MUCH!  I am sending you a great, big bear hug over the Internet.  That was my problem -- I'd watched Jamie Wallen's tension video on YouTube where he recommends a really loose tension, and I had my tension balanced with my bobbin set at about 160.  I reset my bobbin to 200 per your suggestion and increased upper tension to rebalance my stitch, and the problem disappeared instantly.  I can't tell you how much I appreciate your help.

Two related questions: 

1. I have been using my TOWA gauge on a stable table surface when I take my readings, but I recently read where another long arm quilter was recommending holding the gauge vertically against a wall to take a "correct" reading.  I can see how that better mimics the way the bobbin case is oriented in our machines and the impact of gravity, etc., but it results in a very different tension reading (by about 50) versus taking the reading with the TOWA laid flat on a table.  My suspicion is that, when I'm consulting a bobbin tension guide from Superior Threads or getting TOWA tension recommendations here in the forum, those are based on readings with the TOWA set on a flat surface.  Is that correct, or am I the only person on the planet who hasn't been holding her TOWA gauge up against the wall?

2. I have the M hook on my Millie, which has a little pigtail guide that APQS recommends "in most situations," per the user manual.  But I'm finding that, if I thread that little pigtail, it puts significant additional tension on my bobbin thread and limits my ability to fine-tune the bobbin case tension.  Should I just ignore that little pigtail altogether or am I missing something about how to use it properly?  I think I remember reading that the pigtail guide is meant to ensure that the bobbin thread is aligned correctly when the hook comes around, to prevent skipped stitches, but I have never had any skipped stitches on my Millie, regardless of whether that little pigtail guide is threaded or not.

Thanks again for the help -- this forum is such a wonderful resource!

Rebecca Grace

[jimerickson]

I use my TOWA on the table top.

I don't have a pig tail on my bobbin cases, and don't really see a need for it.  My Happy commercial embroidery machine has a pig tail on it's bobbin case which I'm sure helps with sudden direction changes, but those kinds of direction changes are much less frequent with long arm quilting.  If you find tension adjustments easier without the using the tail, then don't use it.  You could go further and buy a replacement bobbin case without the pig tail.  I think the model you need is BC-DBM(1)NBL3.  You can find them online.  I've bought mine off e-bay.  If you shop online, look for bobbin cases made in Japan, not China.  The quality control on the Chinese ones are kind of hit and miss.  You might get a good one, then again, you might not.  I like TOWA, but Koban or Hirise are good.  Jim