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.

[Wizcrafts]

If a #20 needle breaks and she isn't pulling hard on the material, then needle deflection caused by thread tension is a possible cause. Reducing both top and bobbin tensions, rebalancing the position of the knots, should help alleviate this deflection. Also, check the feed dog and make sure it is not moving at a different rate than the needle. The Juki may be equipped with an adjustable rate feed dog control, used to ruffle curtains. This would be a bad setting for flat work.

If she is trying to force the work around the turns, the needle may be deflected into the feed dog surface.

If she has to move up to a bigger needle,she may have do the same with the thread. Otherwise there will be huge holes with tiny thread. The normal needle-thread combinations for upholstery grade walking foot machines are as follows.

• #69 thread: #18/110 needle
• #92 thread: #20/125 needle
• #138 thread: #23/160 needle

Edited September 22, 2015 by Wizcrafts

[Art]

A lot of times, breaking a needle is a result of crashing it into a feed dog or needle plate. Like Wiz says, easy to do when sewing a rounded corner. When you break a needle, you should recover ALL if it. There is some chance it can get down into the bobbin and/or hook and score-up the race. Get a little magnet (all sorts of that stuff from Harbor Freight) pen or pointer thingy, might be called a part retriever. Also, when sewing-in welts around a corner, make sure the welt foot has the back cut out to the left (or whatever way you are sewing) or the cord will make it want to go straight (and possibly push the needle into the dog). On tiny cords it is not much of a problem, but on the big stuff, if the back of the foot is not cut, it's like riding the monorail at Disney World. Also, if you are going to be doing boating canvaswork (not much canvas anymore, sunbrella now), Use Tenara thread or something else you can get in clear, that way you don't have to stock a bunch of colors; and yes Tenara is THAT expensive, so learn to sew and use your machine first.

Art

[KelseyR89]

If a #20 needle breaks and she isn't pulling hard on the material, then needle deflection caused by thread tension is a possible cause. Reducing both top and bobbin tensions, rebalancing the position of the knots, should help alleviate this deflection. Also, check the feed dog and make sure it is not moving at a different rate than the needle. The Juki may be equipped with an adjustable rate feed dog control, used to ruffle curtains. This would be a bad setting for flat work.

If she is trying to force the work around the turns, the needle may be deflected into the feed dog surface.

If she has to move up to a bigger needle,she may have do the same with the thread. Otherwise there will be huge holes with tiny thread. The normal needle-thread combinations for upholstery grade walking foot machines are as follows.

• #69 thread: #18/110 needle
• #92 thread: #20/125 needle
• #138 thread: #23/160 needle

Hey Wizcrafts!

Was wondering if you'd be able to help me with something that I haven't been able to find an answer for. On my searches you replied to many people with very helpful answers so I'm hoping you could help me out too I recently bought my first sewing machine, a Seiko STH-8BLD-3 and after much work have finally got the tension right. However, I've noticed all along that the beginning and ending stitches aren't super tight and I can somewhat lightly pull on the thread after cutting it and the stitches will pop right out! I'm not sure if this is related to the tension (I have the tension the best it's been yet and the stitches are still popping out) or if I'm doing something wrong.

I've been doing 2 back stitches starting and beginning, but even then it doesn't matter because as soon as you pull the thread it pops out. If there's any advice you could give I'd appreciate it! I am so ready to start using this for my products

Thank you!

[Wizcrafts]

Kelsey;

Try backstitching three stitches and hold both threads taut as you do so, until you pass the starting stitch. Make sure that the knots are as centered inside the material as is possible. Finally, use a smaller needle if all your stitches are loose (experiment).

The travel of the check spring has an influence on the stitch tightness. Longer travel makes for tighter stitches all around. But, too much travel can dissolve the loops before the hook picks them off.

[stickandtin]

Wizcrafts-

Took your advice about checking top and bottom tensions on the 1541S. Backed off both, then started tightening both a little at a time. After each tightening, I would run about 3 inches of test stitches on two layers of scrap marine vinyl. I could see improvement in the tightness of the stitches after each adjustment and test run. After the 12 test run, I felt the stitches looked like they were where they should be. I then doubled the marine vinyl over again so there were four layers. Ran it through the machine and stitches looked great top and bottom. Wife then started sewing seat covers out of the marine vinyl for chrome dinette chairs. After about ten minutes of sewing I checked stitches. Now there is intermittent tiny balloons on the bottom. Machine will stitch tight, then she'll get about an inch or more of tiny balloons on bottom, then tight stitches again. Doesn't matter if it is around a corner or on straight run. Do you have any idea why the machine is doing this? Thanks.

[stickandtin]

I should add that she is sewing piping using the correct size piping foot into these chair covers. She made the piping using plastic welt cord and covering it with marine vinyl. So in essence she is sewing through 4 layers of marine vinyl. She is using a #20 needle and #69 thread.

[Wizcrafts]

The intermittent "tiny balloons" on the bottom would be thread knots or even top thread loops on the bottom. There would be two things that would account for this.

1. The top thread is twisting up in the upper tension disks, out of the primary pressure zone, causing it to lose tension
2. The bobbin was wound incorrectly, or is warped and is binding intermittently

Check the spool of thread to see if it comes off the spool like a coil spring. If so, place a funnel on top of the spool and feed the thread through the spout, up to the thread guise on the stand. Then, when it gets to the three hole thread guide near the top tensioner, go through all three using a wrap around technique. This may counteract the twisty thread.

The opposite can happen if the bonding on the thread is sticky in some areas and loose in others. Examine the cone and see if the thread sticks too much intermittently.

Wind a fresh bobbin load, using a fairly strong amount of tension on the disks on the far end of the winder assembly. You want the bobbins to be loaded tightly and evenly all the way across. As the bobbin is loading, check it for out of roundness. If the sides are bent the booin may bind inside the bobbin case.

Check the bobbin case tension spring and slot for thread pollution. A ratted piece of thread can cause intermittent tension changes. You don't need a lot of bobbin tension. Use just enough to get a decent lay on the bottom, with the knots buried between the layers. Then you won't need as much top tension either.

Finally, make sure that the top thread is feeding through the check spring and adjust its travel to see if it makes any improvement, or worsens the issue. The adjustment should be set bey a little screw in a curved slot on the disk facing forward, over the check spring. One direction lengthens the travel and vice-versa.

[stickandtin]

Thanks wizcrafts. Boy this machine sure is sensitive. But when it's on, it is incredible. Do you think the #69 thread is too light for 4 layers of marine vinyl? Should she go up to #92?

[Wizcrafts]

Thanks wizcrafts. Boy this machine sure is sensitive. But when it's on, it is incredible. Do you think the #69 thread is too light for 4 layers of marine vinyl? Should she go up to #92?

Sure. #92 thread has 15 pounds test, as opposed to only 11 for #69 thread. If you do that, use #20 round point needles.

[stickandtin]

Ok, she'll give it a try see how it works. Thanks for all the tips.

[Wizcrafts]

Bigger diameter needles are deflected less than thin needles, for any given length. The longer the needle system, they greater the deflection.

Needles get deflected by the thread pulling on the way down, as well as by the last stitch on the upstroke. The more tension you have on the thread, the greater this effect will be.

As I said before, when sewing Naugahyde, you should back off top and bobbin tensions. It shouldn't take much tension to bring the knots up between the two or four layers. Move up one needle size if necessary.

[Paulmin]

I've been reading some threads here with anticipation of seeing my issue. I will inject that I have a Consew 1541 like the juki namesake. The problem I have with loopy stitching is right after a corner turn. The lower thread gets all loopy. When sewing vinyl it become much more noticable of an issue. I have another machine a 205RB and it sews the vinyls fine. The 1541 sews well except on corners and worse on corners with vinyl. All this is when using 5/32 welt cord and a 1/4" welt foot. Have tried a few welt feet. I'm going to see if the needle is being deflected when turning corners. I us a 140 needle and 69 polyester thread.

  Interesting threads here I must say.

 

[brmax]

Do you use the same needle size in the other machine. Possibly with bigger thread, just curious why the 140 vs a 110 maybe. 

Not that this would have a big effect here, but i do like to ask. 

 

Have a good day

Floyd

[dikman]

140 needle is a bit big for #69 thread.

[Paulmin]

Same size needle 140s in both machines. I use 110 or 120s when sewing thinner material but it misses on thick stuff like vinyl and other thicker fabrics so I go to 140s.