Bobbin Loading Issues

[Chelsie44]

Hello!

I am trying to figure out my Juki  machine and my bottom stitch just isn't panning out. I'm 99 percent sure it's operator error and was hoping I could get some tips!

I think it has something to do with my bobbin and how I am loading it 

 

Thank you! 

Edited August 2, 2017 by Chelsie44
Picture

[Uwe]

The picture doesn't really tell me much detail about how you're loading the bobbin. For remote debugging, you're going to have to give us little more to work with.

What model Juki your machine is and what do you mean by "isn't panning out". Do you have a user manual for the machine? What does the manual say about loading the bobbin? If you don't have a manual, have you looked for one online?

 

[Wizcrafts]

We'll need photos of the stitching on top and bottom of a representative piece of leather. Remove the bobbin temporarily and reinsert it so the thread feeds counterclockwise, against the slot in the case.This is the most reliable direction of feed in most instances. Make sure that the windings aren't overflowing the edges of the bobbin. 

Make sure you line up the tab on the case with the indent on the housing and make sure the bobbin case snaps in all the way.

[Chelsie44]

It is a DNU 241H. I have a manual but it is very basic, I have also watched numerous YouTube videos but what I am unsure of is what I need to with the thread tail that comes out of the casing after it has been loaded. I have pictures of the bottom side but will need to take some of the top. 

[Gregg From Keystone Sewing]

Make sure the feed dog carrier is set to the correct height.

I've checked the owners book and it does not cover this.  When you cycle the machine by hand, the bottom valley of the feed dog should be at the same level of the needle plate.  Hope that helps.

 

[Uwe]

The picture may indicate something else in the thread path going on. Your top thread path may not be right.

 

Your top thread may snag somewhere as it wraps around the hook and bobbin. Maybe the bobbin case opener doesn't work right. 

As for the tail of the bobbin thread after installing, you pull it up through the feed dog hole. Hold the top thread and make one manual turn.

Make sure the bobbin thread is under the tension spring of the bobbin case and that you have very light tension as you pull the thread (30-50g) 

This Juki DNU-241H manual (http://www.raichert.com/adobe/dnubook.pdf) has a little more than the basics.

Edited August 2, 2017 by Uwe
added pics

[Wizcrafts]

From the photos of the underside it seems that either there is too little top tension, or too much bobbin tension, or the needle is too small for the thickness of the thread.

First, make sure you are following the full thread path and that the bobbin tension is not too high. If the knots can't be pulled up inside the leather, try a larger needle.

There is a needle and thread chart on the Toledo Industrial Sewing Machines website. Find the size of thread you are trying to use and it will show the best needle size or sizes to use.

For instance, if the thread is #138 (the maximum your machine is rated for), and the needle in it is a #22, move up one number to a #23 needle (leather point). The largest needle your machine may take is a #24. It gets harder to punch through as the needles get bigger. Thicker thread forms much bigger knots than thinner thread and is harder to pull up.

If your thread is larger than #138, stop ruining your machine and buy some #138 thread, along with #22 and #23 leather point needles.

[Chelsie44]

I am using 138 thread with a #23 needle.

I have checked my threading for the top side  and bobbin loading against the picture Uwe posted. My thread guide is a little different though. 

It looks like it is skipping a stitch on the top as well. 

[Wizcrafts]

Tighten down the pressure spring and run that sewing test again. If the pressure spring isn't tight enough to hold the feet firmly on the leather, the leather can lift with the needle and you'll have skipped stitches.

[Uwe]

I'm still putting my money on the top thread snagging somewhere below the throat plate. You don't get big loops of top thread underneath like that unless more top thread is pulled from the spool at the wrong time, leaving the take-up lever without a chance to pull the knot tight.

I may sound like a broken record to some: Take the belt off the hand wheel and do a few very slow, hand-turned stitches and really look, feel, and listen for anything that is not how it should be. Knowing how things should be is often the hard part. "Smooth and without hang-ups" is a good starting point.

Edited August 3, 2017 by Uwe