Juki thread jamming
 

I'm hoping to get some feedback and help, because I'm ready to pull my hair out. I purchased a new Juki HZL-NX7 (Kirei). I love the machine and features, but am encountering a really strange issue that I can't resolve.

My main sewing is quilting (cotton). The machine is constantly snagging and birds-nesting. I've narrowed it down to if I'm doing single thickness, all goes smoothly for the most part. But if the machine "perceives" a shift in thickness it suddenly makes a horrific knocking noise in the bobbin area, and the thread snags. When you pull it out, the back of the fabric is loops of snagged thread.

I've tried everything - replacing the thread, replacing the bobbin thread, thread tension, pressure foot pressure, different needle. Nothing works. On a straight path with a piece of fabric that is one width, it's fine. The minute there is any "change", the machine goes bonkers. Just as an example, I'm doing a cathedral window quilt. I'm stitching the points of each envelope. It starts out ok, then gets to the end of the point and the minute it gets to that little bit of bulk from the point, it grinds and bird-nests.

The machine is brand new (just a few days old). I don't have a dealer nearby, and unfortunately can't drive due to epilepsy. The company I purchased from has an excellent return policy. But I do like the features of the machine, so I'd really rather not return it if I don't have to. I'm hoping somebody can offer some suggestions, as it very well could be "operator error" (I'm not ruling that out, this machine is very new to me). I just find it strange that a machine of this cost wouldn't be able to sew smoothly over various thickness material (within reason) without doing this.

Thanks in advance for any suggestions!!

You are correct, this machine should be able to sew just about anything with no problems. This does not sound like operator error to me, sounds like it wasn't timed properly before being sent out the door, or something slipped during shipping.

Or there could be a manufacturing defect that wasn't caught. Many places do almost no quality control, they leave that to the buyer. I'd send it back and get a new one.

I've emailed the store/seller to see what they say. I have pretty much tried every "trick" I could find online with no luck. No matter what I do, it happens. The minute the machine encounters a slightly thicker fabric, it goes bonkers https://cdn.quiltingboard.com/images/smilies/mad.png

I agree with the quilters above. Your new machine should not be doing this especially since it is brand new. I would take it back into your dealer and have it checked over. Sounds like a timing issue to me.

Try increasing the presser foot tension. Not sure how to do it on that particular machine, but it might help.

Also, remove the bobbin basket and see if there's damage. Sometimes the needle will go right through it, or rough it up. You can smooth it out with a very fine sandpaper -- about 400 to 600 grit. It only takes a few swipes with the sandpaper -- be gentle.

Sometimes, the "finger" that holds the bobbin basket in place needs to be adjusted. There should be a very small space between the finger and the bobbin basket, so it has some wiggle room. If it's too tight, it's a problem. If it's too loose it's a problem.

Sometimes the bobbin basket jumps past the stop spring in front of the bobbin basket.

I know people get upset with me when I say it, but I see this problem with the plastic drop-in bobbins jamming when trying to sew over uneven or heavy fabrics, all the time!

I have had a Juki and have not encountered that problem before.

I would read the manual very carefully.

To lessen or tighten the pressure on the foot - it is the knob directly up from the needle. Make sure the race is oiled. My Juki needs to be oiled.

I would contact the seller and tell that you need a "return" label because you're shipping the machine back and for them to send you another machine, and make sure that it works properly. This is why I don't buy machines online, if you buy from a dealer, you should get lessons with and for the machine you purchase.

Since this is a new machine, don't try to "fix" the problem or work around it. It sounds like it could be a timing issue, as Cathy said. The dealer may be able to help you.

I read the entire manual, even the corrections that were included. It isn't very in-depth and really only covers what each button means, how to adjust things, etc.

I tried both lessening and tightening the presser foot, with no luck. I've also narrowed down that it happens without fail the minute you switch to a stitch that isn't a straight stitch. With the straight stitch it will work pretty well for a while, then the minute you get to a thicker portion of material, it jams. If you switch to a zig zag stitch, it happens almost immediately, no matter the fabric.

I guess where I'm confused is if I have to tweak settings, I understand, but if material isn't one thickness (say a quilt sandwich) how would that work? I have to stop and adjust before a hump? (just trying to explain what is happening)