Backlash issue with Juki 1541 & bonded thread

[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!