Backlash issue with Juki 1541 & bonded thread

[aslfkjaslfkjasflkj]

I am using V69 Bonded Polyester thread in my Juki 1541 and I'm having backlash issues.

I'm using steel bobbing and I have tried tightening the bobbin tension to no avail. I have tried using a backlash spring (pictured) however this causes inconsistencies in the stitch and I still sometimes get backlash. I have tested with the spring in a tension guage and the tension goes up and down. Without the spring it is consistent. I have also tried multiple springs.

I sew at 100spm and at this point I'm at my wits end. 

Is there anything I'm missing?

Kind Regards 

Edited December 11, 2021 by aslfkjaslfkjasflkj

[Wizcrafts]

Always insert the bobbin so it feeds against the direction of the hook. If the hook turns clockwise, insert the bobbin counterclockwise. This may cause the bobbin thread to me a sharp turn into the slot that feed under the tension spring. I find this to be more controllable unless the thread is particularly sticky.

[aslfkjaslfkjasflkj]

20 minutes ago, Wizcrafts said:

Always insert the bobbin so it feeds against the direction of the hook. If the hook turns clockwise, insert the bobbin counterclockwise. This may cause the bobbin thread to me a sharp turn into the slot that feed under the tension spring. I find this to be more controllable unless the thread is particularly sticky.

I think I have tried this in the past however I will try again.

Just to be clear, when you refer to the rotation of the hook. If I load the bobbin from the side and look at the hook from this angle, in my case the left side of the machine. The hook spins counter clockwise. So I should insert the bobbin so that it spins counter clockwise as when inserted this will spin opposite the machine. Hopefully I got that right.

Also should I bother with the backlash spring? As the inconsistency in tension leaves a poor stitch which in my opinion is worse than the backlash as most of my sewing consists of straight lines and not having to stop.

Thanks

[Wizcrafts]

33 minutes ago, aslfkjaslfkjasflkj said:

Also should I bother with the backlash spring? As the inconsistency in tension leaves a poor stitch which in my opinion is worse than the backlash as most of my sewing consists of straight lines and not having to stop.

If the spring interferes, leave it out. Load the bobbin so it feeds against the rotation of the hook and make sure you feed the thread under the tension spring and that there are no thread stubs stuck in the slot or spring. Then adjust the bobbin tension for a smooth, steady pull. If you use the proper needle size for the thread combination, the top tension should bring the knots into the center of the work, consistently. Watch the thread spool as it unwinds to see if it is forming kinks. Some machines have a top post with multiple holes that allow you to loop the top thread around upper and lower guide holes in the opposite direction of the twist of the thread. This can counteract excessively twisty thread.

[aslfkjaslfkjasflkj]

59 minutes ago, Wizcrafts said:

If the spring interferes, leave it out. Load the bobbin so it feeds against the rotation of the hook and make sure you feed the thread under the tension spring and that there are no thread stubs stuck in the slot or spring. Then adjust the bobbin tension for a smooth, steady pull. If you use the proper needle size for the thread combination, the top tension should bring the knots into the center of the work, consistently. Watch the thread spool as it unwinds to see if it is forming kinks. Some machines have a top post with multiple holes that allow you to loop the top thread around upper and lower guide holes in the opposite direction of the twist of the thread. This can counteract excessively twisty thread.

Thank you for the help thus far.

I am using a thread guide pin/top post and threading it counterclockwise opposite of the direction coming off the spool.

The needle size is something I'm a bit unsure of. I was originally using size 18 serv7 needles. Which seemed fine for a few layers of 1000d and lining however I'm now sewing bag pieces together where I have a minimum of 7 layers and up to 14 in some parts of the same stitch. I then sized up to a size 19 needle.

Would this be too large? My thought was that the thread seemed to be having a hard time going through thicker seams so I sized up.

[kgg]

3 hours ago, aslfkjaslfkjasflkj said:

I'm using steel bobbing

I assume you mean bobbin. My Juki 1541S can be cranky with bobbins if I mistakenly use an after market bobbin while the Juki bobbins never give me a problem. That said if you are having problems with a backlash spring don't use it. Also I find if I use a bobbin that has been wound with thread for more then a couple of days before use it I may have problems as the thread will develop a coil spring memory and cause problems. I also found that using 8 oz spools of thread created problems both with the top thread and bobbin thread with black thread being worst. I would do as Wiz suggested and also change the spool of thread to a brand name preferably in a 16 oz spool size.

Can I ask why you are using V69 thread and what you are trying to sew. If the material is to thin it may not be a backlash problem my Juki hates thin stuff. You may have better luck using V92 as a top thread and bobbin thread. A couple of photo's of your thread path would also help.

kgg

[aslfkjaslfkjasflkj]

49 minutes ago, kgg said:

I assume you mean bobbin. My Juki 1541S can be cranky with bobbins if I mistakenly use an after market bobbin while the Juki bobbins never give me a problem. That said if you are having problems with a backlash spring don't use it. Also I find if I use a bobbin that has been wound with thread for more then a couple of days before use it I may have problems as the thread will develop a coil spring memory and cause problems. I also found that using 8 oz spools of thread created problems both with the top thread and bobbin thread with black thread being worst. I would do as Wiz suggested and also change the spool of thread to a brand name preferably in a 16 oz spool size.

Can I ask why you are using V69 thread and what you are trying to sew. If the material is to thin it may not be a backlash problem my Juki hates thin stuff. You may have better luck using V92 as a top thread and bobbin thread. A couple of photo's of your thread path would also help.

kgg

Yes I meant bobbin. I am using aftermarket bobbins so I might look into some genuine ones if I can't get this resolved. I've also read that aluminum bobbins are supposed to be better for backlash. Any input of this?

I will update this thread on monday with my thread path. I am using A&E Sunstop 3000m v69 grey thread.

I am sewing a sling bag. I'm using 1000d PU Nylon and ripstop lining. I am now sewing all the pieces together, which as mentioned previously I have a minimum seam of 7 layers up to 14 in some parts.

I've had issues with consistent stitches but I put this down to a number of things. This machine is second hand and didn't come with all the thread guides etc. I recently purchased all the missing parts. But I still have issues with the backlash. I've always placed the bobbin into the case as shown in the manual. I will try it the other way as wiz suggested.

 

[Wizcrafts]

1 hour ago, aslfkjaslfkjasflkj said:

I am sewing a sling bag. I'm using 1000d PU Nylon and ripstop lining. I am now sewing all the pieces together, which as mentioned previously I have a minimum seam of 7 layers up to 14 in some parts.

I would seriously think about moving up to #92 (T90) thread for this thickness and a #20 needle. Normally, I use a #19 needle with #92 thread. But, sometimes the little extra diameter of a #20 needle makes it easier to balance the knots. You are sewing tough material. Number 69 thread has under 11 pounds test. Number 92 is rated at 15 pounds and is less likely to rip apart under stress from so many layers In fact, you might even be able to get away with #138 thread, rated at 22 pounds test, using a #22 needle. Experiment!

I sew a lot of patches onto leather vests. I find #69 thread to be barely acceptable for low stress patches, or for soft leather, or denim. But, if I am sewing through a thick vest and the patches are substantial, I move up to #92 thread and a #19 needle.

[kgg]

1 hour ago, aslfkjaslfkjasflkj said:

I've also read that aluminum bobbins are supposed to be better for backlash. Any input of this?

I have some of those as they came with my Kobe LS 1341 and I will not use them. The tolerances and balance can be all over the place so I don't think they would be of any benefit.

1 hour ago, aslfkjaslfkjasflkj said:

I am sewing a sling bag. I'm using 1000d PU Nylon and ripstop lining. I am now sewing all the pieces together, which as mentioned previously I have a minimum seam of 7 layers up to 14 in some parts.

I don't think you are having as much a backlash problem rather a problem with the material. I find that to sew thin stuff particularly with ripstop it can become a real balancing act in getting the bobbin thread to properly set. I put the problem down being caused by the makeup of the ripstop. I find some things that are less then 4 to 5mm in thickness a bit of a chore with the 1541S so for those items I use the less capable 1181n. A good reference to show how the 1541 reacts with light, medium and heavy fabric take a look at youtube.com/watch?v=4JES-2I7h3o versus the less capable 1181N with the same material youtube.com/watch?v=IKJuKTrjsbw&t=300s

kgg

[aslfkjaslfkjasflkj]

1 hour ago, kgg said:

I have some of those as they came with my Kobe LS 1341 and I will not use them. The tolerances and balance can be all over the place so I don't think they would be of any benefit.

I don't think you are having as much a backlash problem rather a problem with the material. I find that to sew thin stuff particularly with ripstop it can become a real balancing act in getting the bobbin thread to properly set. I put the problem down being caused by the makeup of the ripstop. I find some things that are less then 4 to 5mm in thickness a bit of a chore with the 1541S so for those items I use the less capable 1181n. A good reference to show how the 1541 reacts with light, medium and heavy fabric take a look at youtube.com/watch?v=4JES-2I7h3o versus the less capable 1181N with the same material youtube.com/watch?v=IKJuKTrjsbw&t=300s

kgg

I will checkout the links you posted.

I am 99% sure this is a backlash issue. I didn't mention this previously, my bad. When I am sewing constantly I have little to no issues. My problem is when I stop sewing. The stitch will be fine until I stop, when I begin sewing again the first stitch or first few stitches will pull the bobbin thread to the top. As far as I'm aware this is thread backlash. Maybe I am wrong. I hope this clears things up a bit.

I will post in this thread on Monday more details with my current setup including thread guide path.

Kind Regards

[Dream4est]

Backlash is the loosening of the bobbin thread inside the case. It usually is an issue on automatic machines that cut the thread. If you are experiencing stitch errors starting a seam on 1541 its user error imo check your technique.  Holding tails, top dead center start etc. 

That machine doesnt do v69 thread without adjustment it likes v92 with a 20 or 21 needle imo. I have the 1181 in direct drive auto clone model and it doesnt like 18 needles and v69 that much either on similar material. I sew that stuff with v92 and a 21 and holes are acceptable but not with a 22 and v138 on top hole too big with thin assemblies i.e. 4 layers outdoor material and 2 layers ripstop liner. 

edit- I run away from any poly thread like super fast - only bonded nylon in these walking foot machines IMO. 

Edited December 12, 2021 by Dream4est

[kgg]

17 hours ago, aslfkjaslfkjasflkj said:

When I am sewing constantly I have little to no issues. My problem is when I stop sewing. The stitch will be fine until I stop, when I begin sewing again the first stitch or first few stitches will pull the bobbin thread to the top.

When you stop are you keeping the needle buried in the material like if you were making a 90 degree turn or is the needle above the material with little pressor foot pressure being applied?

44 minutes ago, Dream4est said:

That machine doesnt do v69 thread

I agree the machine needs to be dumbed down to handle V69 but preforms much better with V138 even my 1181n prefers V92.

 

48 minutes ago, Dream4est said:

I run away from any poly thread like super fast - only bonded nylon in these walking foot machines IMO

I do use polyester thread for items being regularly exposed to the outdoors UV or for items that are being exposed to a lot of bleaching as it stands up considerably better then bonded nylon. That is why I use brand name thread like A&E or Coates thread as they have a wide selection depending on what someone is planning on sewing. Yes it is more expensive but they seem to have put a bit of engineering into their products rather the one size fits all, sort of like panty hose, offered by the less expensive off shore stuff.

kgg

[aslfkjaslfkjasflkj]

59 minutes ago, Dream4est said:

Backlash is the loosening of the bobbin thread inside the case. It usually is an issue on automatic machines that cut the thread. If you are experiencing stitch errors starting a seam on 1541 its user error imo check your technique.  Holding tails, top dead center start etc. 

That machine doesnt do v69 thread without adjustment it likes v92 with a 20 or 21 needle imo. I have the 1181 in direct drive auto clone model and it doesnt like 18 needles and v69 that much either on similar material. I sew that stuff with v92 and a 21 and holes are acceptable but not with a 22 and v138 on top hole too big with thin assemblies i.e. 4 layers outdoor material and 2 layers ripstop liner. 

edit- I run away from any poly thread like super fast - only bonded nylon in these walking foot machines IMO. 

My issue isn't starting a seam. I started a seam by holding the tails tight and sewing back and forth securing the stitch.

My issue is when I stop mid stitch. When I stop the bobbin continues to spin thus loosening the bobbin thread. When I begin to sew again the bobbin thread gets pulled up to the top side of the material. After a few stitches the bobbin thread goes back under tension and I don't have another issue until i stop. Then the problem repeats.

Can I ask why you dislike bonded poly? What are the differences compared to bonded nylon?

[aslfkjaslfkjasflkj]

1 minute ago, kgg said:

When you stop are you keeping the needle buried in the material like if you were making a 90 degree turn or is the needle above the material with little pressor foot pressure being applied?

Yes, I have needle positioning so when I stop the needle stays in the fabric at the same point each time. Presser foot also is applying pressure and I have increased the pressure substantially but no change.

 

3 minutes ago, kgg said:

I agree the machine needs to be dumbed down to handle V69

What do you mean by this? How does one "dumb down" the machine?

Also if I size up to v92 how exactly would this solve the backlash issue? Being in the UK there isn't that much choice when it comes to bonded threads.

[Dream4est]

8 minutes ago, aslfkjaslfkjasflkj said:

My issue isn't starting a seam. I started a seam by holding the tails tight and sewing back and forth securing the stitch.

My issue is when I stop mid stitch. When I stop the bobbin continues to spin thus loosening the bobbin thread. When I begin to sew again the bobbin thread gets pulled up to the top side of the material. After a few stitches the bobbin thread goes back under tension and I don't have another issue until i stop. Then the problem repeats.

Can I ask why you dislike bonded poly? What are the differences compared to bonded nylon?

Maybe you could try a piece of cloth or material as your backlash spring as a test if you really feel its backlash and not a layer of ripstop top or bottom doing it (ripstop sewing is hard to keep knots all dialed tight in thin assemblies). I have about 2 layers of outdoor material superglued in a juki 1181 case I use as a backup to my case for my auto clone to stop backlash as the 3 spring setup I use in the stock case wont sit in the Juki case.

I mentioned nylon as IMO the poly sews like crap. Always fraying ends and such seems to unravel etc. Thats just my .02. It could even be why you get these issues. In my bar tack machine the v69 poly is easily frayed on the cut to the point of a near miss tack. 

[kgg]

14 minutes ago, aslfkjaslfkjasflkj said:

What do you mean by this? How does one "dumb down" the machine?

I have had to changed the height of the feed dog so it isn't as aggressive, severely reduced the pressor foot tension so the material isn't being forced down into the feed dog opening, run a layer of tear away paper between the feed dog and the material so the material doesn't ruffle / bunch up / curl.

If the bobbin is spinning once the bobbin holder has stopped rotating my thought would be to install the bobbin in reverse so the thread is being removed from the bobbin against the direction of the bobbin case rotation. Also this could be probably caused by bobbins with the centers being out of spec like some aftermarkets ones have been known to be.

kgg

[Dream4est]

One trick I use in these instances that has worked every time for me is to install a pre wound bobbin. They cant backlash the thread is super tight and almost bound together. I keep some G size v92 black pre wounds handy as backups just because the 1181 auto clone has occasional backlash issues with aluminum bobbins and springs etc. The G work in M cases really well just not full size. 

edit- If I was trying v69 on any of my triple feed machines I would have to consider that the check spring in the upper tension assembly is way too aggressive at stock setting. I tried the same experiment on a Singer 168g101 this week and with a stock check spring setting (from 138/92) I was not able to just change the upper and lower tension and sew a corner with 18 or 19 needle. Sometimes the lockstitch would even not form in sewing a straight line. Sometimes it would sew straight well but never did a top corner come out it was always pulled out. I quit before major adjustments were to begin and put 138/92 and 22 needle back in.

Edited December 12, 2021 by Dream4est

[Wizcrafts]

1 hour ago, Dream4est said:

If I was trying v69 on any of my triple feed machines I would have to consider that the check spring in the upper tension assembly is way too aggressive at stock setting.

It is a simple matter to loosen the set screw in the hosing for the check spring, then use a screwdriver to rotate the split shaft one way or the other until there is just enough pull to bring the spring all the way down against the bottom stopper bracket. That bracket can be moved up and down to control how long the spring keeps tension on the top thread. By carefully balancing the travel and force, you can get a decent check spring adjustment. All that remains is the position of the screw inside the curved slot. Normally, rotating the assembly all the way clockwise tightens the slack and the other way loosens the slack thread. Standard position is dead center in thee slot. I only turn it fully ccw if I need more slack thread on top. This might be if I hear the thread snap as it goes around the bobbin case/shuttle.

[Dream4est]

Ok Wiz I tried it and I guess the stock spring can be set soft enough for some reason I thought it couldnt and was too stiff but you are right there is a decent range I would say even more than decent. I adjusted a little more than slight turn of the post I went to slack and then came back some.  Thanks. I sewed v69 in 4 layers ripstop and 1 layer cordura1000 with a #18 needle and corners are money!

[Wizcrafts]

48 minutes ago, Dream4est said:

Thanks. I sewed v69 in 4 layers ripstop and 1 layer cordura1000 with a #18 needle and corners are money!

That's what I'm talking about! That's how you do it!

[aslfkjaslfkjasflkj]

On 12/12/2021 at 5:22 PM, Dream4est said:

20 hours ago, Wizcrafts said:

On 12/12/2021 at 5:16 PM, kgg said:

 

 

 

This is going to be a long post so brace yourself.

Bobbin Winding

This is the thread path for the bobbin winder.

This is my bobbin case which I made sure to clean out before any testing. There wasn't any lint anyway.

When the bobbin is winding it appears to "wobble" not sure if that's normal. Here is the video of this: https://imgur.com/0sp0eqQ

Thread Path

Testing Info

I insert the bobbin so that it spins the opposite way to which the hook spins.

The following images of testing you will see a white line next to some stitches. This white line indicates when I stopped sewing. So you can see where the bobbin thread gets pulled up to the top. Grey on grey isn't the easiest to see but hopefully I have shown it well.

Size 19 Needle Testing

I started off by using a new size 19 needle with a bobbin tension of ~40gf. I tested the tension in a towa bobbin gauge and the bobbin tension was consistent.

To save space here is the rest of the images for size 19 testing: https://imgur.com/a/iWuB4NK

Size 18 Needle Testing

I then switched to a new size 18 needle and I believe I increased the bobbin tension too.

I continued testing and now it got to a point where I wasn't experiencing backlash all the time however it would still occur. At this point my top tension was very tight to the point where it couldn't be adjusted much more. The bobbin tension was also very tight around 75gf. So this wasn't a valid solution.

Rest of size 18 needle testing: https://imgur.com/a/HWBzMsU

I also tested on 1000D Cordura 4 Layers with a size 19 needle. As many have said the 19 needle is too large for this. However when I use the same needle on the 1000D with ripstop lining its as if the ripstop creates a lot of friction and I have to increase my top tension significantly to account for this. Is this something anyone else has experienced?

Backlash Spring Testing

I now decreased my bobbin tension to ~40gf and inserted a brand new backlash spring. However I have a problem. I have seen bobbin cases like this:

This case has a slot for the backlash spring to sit in however mine do not so I insert the spring as follows:

I am unsure as to if I should put it above or under this little piece:

I put it in the tension gauge and as usual the bobbin didn't have consistent bobbin tension. As a matter of fact, this time the tension WITH the backlash spring, the bobbin tension decreased to ~34gf from 40gf which I have never experienced before. It has always increased the tension in the past.

I continued testing using this current setup and sometimes it worked but not all of the time as you can see in the final images in "Size 19 Needle" imgur link.

Here is a video as to what it looks like when sewing: https://i.imgur.com/OwNAM91.mp4

Final Thoughts

I am unsure as to what else I can do with my current setup. All I can think of is to buy a bobbin case with the slots for the backlash spring as pictured above and some genuine bobbins.

Thank you for taking the time to read this wall of text.

 

 

[kgg]

5 hours ago, aslfkjaslfkjasflkj said:

Bobbin Winding

This is the thread path for the bobbin winder.

I use only one location for my top and bobbin thread pins, the location you are using for your bobbin thread guide pin, but I use the metal thread guide for the top thread and the PLA guide for the bobbin thread. This allows me to wind a bobbin at will without having to undo the top thread. Since you are using the standard thread spool stand you need to get the spools as close to the table as possible and the spool stand arm 2 to 2 1/2 times the height above the thread spool bases or you don't allow the thread to properly untwist. My particular setup has the thread going into the top and bobbin thread pin on top of the machine much closer to horizontal then yours to reduce angle thread tension. 

When I wind a bobbin I thread my bobbin thread through one of the outside holes in the bobbin and it then goes to a swing away thread attachment that holes the end of the thread and automatically cuts the thread flush with the side of the bobbin. I hated the end of the bobbin thread floppy around as I sewed or having to un-thread the needle and hold the end of the thread.

6 hours ago, aslfkjaslfkjasflkj said:

Here is the video of this: https://imgur.com/0sp0eqQ

Thread Path

I would use the thread guide pin location that you use for your bobbin thread and replace the flat horizontal top thread guide on the top cover of your machine as it has some severe thread cuts in it which may nick your thread and cause fraying and come out of the last hole rather then second last hole.

I changed the angle of the next guide to the 2 o'clock position rather then the 3 o'clock position yours is in which did change the entry angle into the top tensioner slightly. The guide just before the takeup arm I changed the position to about the 1:30 position as this helped keep the thread from floppy to much to the left and crossing over to the other side and possible intermingling with the downside of the top thread from the takeup arm. Where the top thread enters the flat spring loaded bar just before the top of the needle should be 1) on the right side of the screw however I haven't found that to makes much difference 2) the flat bar tensioner needs to have the screw tightened in so the thread stays basically in one location with a constant tension so the thread doesn't slide or flop about.

See if that helps.

kgg

 

[DrmCa]

You are wasting so much filament. Much of what you are 3D printing only really needs about 1/2 of its present strength. I know: it is tough. I usually overdo it with my designs and have to push myself to scale thicknesses down.

[Wizcrafts]

49 minutes ago, DrmCa said:

You are wasting so much filament. Much of what you are 3D printing only really needs about 1/2 of its present strength. I know: it is tough. I usually overdo it with my designs and have to push myself to scale thicknesses down.

@DrmCa I think you posted this reply in the wrong topic, or sub-forum. Would you like me to move it to the correct location? Let me know where that is.

[kgg]

10 minutes ago, DrmCa said:

You are wasting so much filament.

I know I usually design the old school way, well over expected load and filament is such a inexpensive medium for prototyping. A lot also depended on that they were designed around my golden rule. No additional holes to be drilled or tap into the machine or table top. The bobbin thread swing-away and the supports has to be able to withstand the breaking strength of V138 thread which is about 22 lb (10 kgs) and any additional bending moment loads where as the snips / needle / bobbin holder on the top front of the machine they all swivel horizontally and vertically so they have to withstand my constant grabbing / banging. All my initial designs for my machines have gone through some form redesign and each machine has it own unique set of attachments to speed up or make things a little easier or be able to repurpose attachments made for a flatbed so they can be used on a cylinder bed. 

kgg