Juki 1541S Lose Stitches

[stickandtin]

Hi all-

After much guidance from this site, bought a new Juki 1541S back in January of this year. My wife is trying to get started sewing upholstery for vintage travel trailers, etc. Started having some issues with the machine. Since both of us are total newbies when it comes to industrial machines, we have no clue how to fix the problems. The Juki manual that came with the machine is one of the poorest written user manuals I have ever seen. Plus, it is impossible to understand for two people with no experience with such a

machine. First issue is loose stitches. My wife right now is sewing marine vinyl covers for vintage chrome dinette chairs. The stitches look tight on top, but when you turn the material over, there are tiny little loops not pulled tight......some are bigger than others. The juki manual says tighten the bobbin tension screw and/or tighten the thread tensioner. I tightened the bobbin tension screw a tiny bit, didn't seem to help much. When I tightened the thread tensioner a tiny bit, the machine would sew for a bit, then break the thread. Backed off the tiny bit of tension and thread quit breaking.

Second issue.....at random, the thread will get pulled all the way to the middle between the thread tensioner discs and breaks. And/or, it jumps behind the takeup spring adjusting plate and breaks. Have no idea why it does this. Any advice/help in correcting these two issues would be greatly appreciated. Wife is sewing this marine vinyl with 69 lb thread.

Thanks, Ron

[25b]

Wife is sewing this marine vinyl with 69 lb thread.

69 pound thread? Do you possibly mean V69 SIZE thread? Because if you are, the "69" does not mean 69 pound tensile strength. V69 polyester thread has a tensile strength of 11 pounds...not 69. I know it may sound like I'm being pedantic, but tensile strength is very important in some applications, so I want to be clear about that in case someone read what you posted and wrongly concluded that v69 thread has a tensile strength of 69 pounds. It is an important distinction to make and it's important to speak precisely about things like this for the sake of accurate information.

On your other issues, if you have loops on the bottom, you need more TOP tension...not bottom (bobbin) tension.

Check that your threading is correct, including the direction the thread goes through the needle. Make sure your needle is installed correctly with the scarf facing the correct direction. Make sure your bobbin is inserted so that it comes out correctly, per the manual.

Finally, I would very highly recommend both of you take a beginning sewing class so you can learn the basics of sewing. It will help a lot to master the basics before taking on larger projects like what you're trying to do now. At the very least, sit down and watch a bunch of youtube videos on various sewing techniques. Sailrite has some decent instructional videos on youtube, for instance.

Edited September 19, 2015 by 25b

[CowboyBob]

On any machne when it is looping on the bottom either your thread isn't threaded correctly OR the upper thread tension is too loose.

It sounds like maybe it's too tight right now because you say when it goes all the way in the tension it breaks.That is where it IS supposed to be all the way in it.So maybe loosen it one turn,pull it all the way in & see what happens.

See attached threading chart.

[stickandtin]

CowboyBob-

You hit the nail on the head. Thread tensioner was too tight. Backed it off and ran several test stitches and examined the tightness of the stitches after each run. Adjusted the tensioner between each pass until the stitches looked good and tight. Thanks for the help and advice. 25b, my bad....thread is size 69 on a 1/2 lb spool. Actually my wife started learning to sew when she was 4, she is now 50. The problem isn't her not knowing how to sew, it's learning the ins and outs of this industrial machine. She has never used a machine like this. Thanks for the help!!

[Wizcrafts]

CowboyBob-

You hit the nail on the head. Thread tensioner was too tight. Backed it off and ran several test stitches and examined the tightness of the stitches after each run. Adjusted the tensioner between each pass until the stitches looked good and tight. Thanks for the help and advice. 25b, my bad....thread is size 69 on a 1/2 lb spool. Actually my wife started learning to sew when she was 4, she is now 50. The problem isn't her not knowing how to sew, it's learning the ins and outs of this industrial machine. She has never used a machine like this. Thanks for the help!!

If she finds that the thread is too tight and is warping the vinyl, back off both top and bottom tensions, balancing the position of the knots. The goal is to set the best laying stitch, at any given stitch length. If it is difficult to get a totally flat stitch into certain thin materials, shorten the stitch length.

[stickandtin]

Thanks Wizcrafts, when you say bottom tension are you referring to the bobbin tension? As a follow up question, wife was sewing some chipboard with a marine vinyl cover. When she started around the rounded corner, the needle broke. This was before we adjusted the thread tensioner. She hasn't tried sewing the corner since the adjustment. She's afraid she'll break another needle. Do you think too much thread tension caused needle to break? Should she switch to a heavier needle for this application? Thanks

[Wizcrafts]

Thanks Wizcrafts, when you say bottom tension are you referring to the bobbin tension? As a follow up question, wife was sewing some chipboard with a marine vinyl cover. When she started around the rounded corner, the needle broke. This was before we adjusted the thread tensioner. She hasn't tried sewing the corner since the adjustment. She's afraid she'll break another needle. Do you think too much thread tension caused needle to break? Should she switch to a heavier needle for this application? Thanks

Yes, bottom tension == bobbin tension spring

What size needle was she using when it broke on the corner? If it was under #20, tell her to try using #20 on the remainder of the project. Moving up to #92 thread is recommended as well (with the #20 needle).

Heavy thread tension usually bends the bottom of the needle to the left. Couple this with turning around a corner in chipboard and a #18 needle doesn't stand a chance

[stickandtin]

Whizcraft, thanks again. I looked at the package of needles that Bob at toledo industrial sent with the machine. It says 10 Nm 125/20. Not sure what all that means. Some other numbers on package are 135 X 17 and DP X 17. Needle brand is Groz-Beckert. Where can I get the # 92 thread. Last time I ordered thread from Bob he said he doesn't carry a big line of thread. Can you recommend a supplier that carries needles and thread. Boy.....we have a lot to learn.

[Wizcrafts]

Whizcraft, thanks again. I looked at the package of needles that Bob at toledo industrial sent with the machine. It says 10 Nm 125/20. Not sure what all that means. Some other numbers on package are 135 X 17 and DP X 17. Needle brand is Groz-Beckert. Where can I get the # 92 thread. Last time I ordered thread from Bob he said he doesn't carry a big line of thread. Can you recommend a supplier that carries needles and thread. Boy.....we have a lot to learn.

Apparently, you already have a large enough needle. The 125/20 is the "size" designation or width indicator. The 125 is the European size and the 20 is the American/Singer equivalent size. The 135x17 or DPx17 are the needle "system," with the x16 being leather point and the x17 round point.

I get most of my thread from Bob Kovar (Toledo Industrial Sewing Machines), including #92. I only buy elsewhere if he doesn't have a color I am looking for in a particular size. Most of his bonded thread is the Cowboy brand and it matches colors across multiple sizes. So, if you buy an 8 ounce spool of a certain color code in #92 and 16 ounce spool of the same code in size 277, the colors will match. You can see the colors and codes of the Cowboy thread here

The color codes are listed in the right sidebar on the Thread page.

[stickandtin]

I should clarify my previous comment. Bob said he didn't carry a big assortment of colors of thread. I'll give him a call and order some #92. Thanks for explaining needle sizes. After reading your post, she broke a #20 needle. Since adjusting the tension, I'll have her try sewing the chipboard again. If the needle does break again, should she get a bigger needle? Just for information purposes, how big a needle can this 1541S take? Thanks for the help Whizcrafts.