friquant

Sounds frustrating. Here are some things to try: Does the machine turn over freely when bobbin and bobbin case cap are removed? (Can turn handwheel a couple revolutions to check no binding) With bobbin case cap in your hand, and the bobbin loaded into it, does pulling on the thread show smooth, even tension? With bobbin case and bobbin installed in machine, but no fabric under presser foot, does pulling on the bobbin thread show smooth, even tension?

Appreciate you chiming in to confirm. 😀 The edge of this shoulder is sharp, so it makes that we want the thread nestled inside the shoulder groove instead of dragging across its sharp edge. Originally (when I took the photos for the beginning of this thread), the feed dog movement was nicely centered in the opening front to back. Shifting it to the rear (away from the user) seems to make it so the thread almost always rides inside the shoulder groove. It's still very clunky though stitching in reverse at 4mm or longer stitch lengths. I'll do my best.. (Hats off to the videographers of the world that make it look easy!) Hopefully this will help to debug. I do love the sound and feel of a machine when it sews smoothly, and it seems I'll never get back to stitching until I unravel this mystery. hook-1-overall-export__small.mp4

In my original post, I reported that after setting the hook-to-needle distance to factory spec it was stitching fine in reverse. Well it's true that the hook is no longer bisecting thread. But it is quite clunky-sounding in reverse with long stitches. Here is a video that shows where it's still hanging up. 😢 This is stitching in reverse at max stitch length. 19-options-36.mp4

@MML Glad to hear the needle positioner is working for others too! I added a reply to the manual that shows how to access the hidden menus. The most useful piece so far is being able to set the upper bound on max speed. 🐎😀

Hidden / Admin Menus After making the original post, I found a video on how to access the hidden/admin menus. To view/edit the hidden menus: 1. Hold P while press "-" 2. Enter number "2013" by pressing "+" "+" "P" "P" "+" "P" "+" "+" "+" 3. Save by pressing "S" 4. Now you are in programming mode with hidden menus enabled Thank you to youtube's @kuchkosol126 who made this youtube video for showing us the hidden menus: https://www.youtube.com/watch?v=Ksw97IGThsg (admin) P-01 (Upper bound on Maximum Speed) This limits how high the user can set their maximum speed Useful!! (admin) P-07 (unknown) default: 1100 range: 800-2000 (admin) P-08 (unknown) default: 0 range: 0-1 (admin) P-09 (uknown) default: 0 range: 0-1 (admin) P-13 (Strange things) When I enabled P-13 the motor would rotate in reverse direction for a quarter stitch, then quickly go forward again. default: 0 range: 0-1 (admin) P-14 (max current) default: 0300 range: 050 - 1000 (I suspect this is non-functional I tried setting this to 050 but my the pulley still slips for me instead of the motor limiting the torque) ### (admin) P-17 (unknown) default: 1 range: 1-3 (admin) P-18 (Set Admin Password) This allows you to change the admin password default: 2013 Thank you to youtube's @kuchkosol126 who made this youtube video for showing us how to set the admin password https://www.youtube.com/watch?v=hrwzXAHG6qc

When a hook has a shoulder, does the thread need to ride in it? The hook on my JiangLong 341 (clone of Juki 341N) has a shoulder to it. When stitching forward, the thread rides in this shoulder. (See the first two photos) When doing long stitches in reverse, the shoulder did not catch the thread so the thread is lagging behind the shoulder. (See last two photos) The reason I am investigating this is to understand how the machine is so noisy when stitching long stitches in reverse. I have set the hook-to-needle timing and the hook-to-needle distance according to the juki manual. I have tried different positions of the latch opener. The latch opens the gate, but the thread does not go through it while it has the chance. Later, the thread gets yanked past the gate....yeek!

By the way, I went looking for a manual for this machine, and I found this one which unfortunately is in several languages: https://www.juki.co.jp/industrial_j/download_j/manual_j/du1181n/menu/pdf/instruction_7K.pdf#page=1 Page 36 begins the section on ratio of movement between the two walking feet

I'm attaching a photo of my machine that has adjustment screws "A" and "B" labeled. "A" adjusts the amount of overall lift (to be shared between the two pressers). "B" adjusts the needle-to-inner-toe timing, and at the same time is what you adjust to achieve equal (or unequal) lifting heights between the two pressers. I'm assuming you loosened "A", raised the arm in the slot, then tightened back up. This is what you would do to be able to walk over bigger humps. (Sometimes I need this set to max to be able step down off of a hump too, or else the back of the outer toe hangs up.) To see how to adjust "B" for equal walking heights, see Uwe's video. In his video he sets it for equal lift height. If you set the lift height slightly UNequal, your needle will land just before or just after the inner toe. You can experiment.

Unread notifications show up under the bell icon in a different color, this is good! But as soon as I click one of those unread notifications, ALL of the unreads change to the color meaning "already read". It would be great if clicking a single notification only marked that item as read, instead of marking them all as read. Don't know how much of a lift that is on the backend..

This thread has been quite the fun read, with good pics

Dahlicious! Especially like the framing of one material (rattlesnake?) within another.

The single thumb screw sounds great! My plexiglass table I still need to do some filing on to get it to sit completely flush. But now I know what to do if I file too far...Steel Stik 😺

I did find discussion about that later in a different post. Guess I'll start practicing my "That's Cool! "

Would like to be able to react to forum posts (and replies) that I read with an emoji. I could add a message to the thread, but I don't want to clutter the thread if only to say "This is cool"

Lift Which piece did you adjust to achieve greater center toe lift? I typically raise the lift of both pressers together, meaning if I have lots of humps to jump I put the lift at its max (with equal lift per presser). Tension In my experience, thicker fabric requires more top tension. So to have no loops, you would need enough tension to match the thickest section of your seam. It's odd that yours is mostly looping only on the transition from thin to thick. If I'm counting your folds correctly, your thickest section is nine layers of denim. I would set up a test piece so you can do an entire seam through nine layers, and use that test piece to sort out needle size and top tension. Give just enough tension to hide the bottom knots on the thick test piece, then go back and see how those same settings do on your standard piece with the thick / thin transitions.

I have not used that needle system, but for my machine there are at least two names for the needle system. So if the needle packaging includes the needle system you're after, I would tend to believe it. Also I found this old post that has a little bit of info on 7x3: https://leatherworker.net/forum/topic/1830-needle-help/ If you do end up going with an alternate needle system in order to get the size/point you are after, at least it's only the needle bar height that needs to change. (Much easier to adjust than hook timing on my machines at least)

Original question, continued... I spent some time moving the hook saddle over to reduce the hook to needle distance. The Juki 341 manual says to make the adjustment with the stitch length set to 3mm, but the Juki 341 has a maximum stitch length of 6mm. One could interpret this at least two different ways: A. Set stitch length to 3mm, or B. Set stitch length to half of the maximum. (The Jianglong 341 that I'm actually working on can make 8mm stitches) Here are photos after my hook to needle adjustment, with stitch length and forward/reverse shown in red text. You will notice that long stitches in reverse prove to give the largest hook-to-needle distance, and I conjecture it was this large hook-to-needle distance that previously had the hook only catching one or two strands of the UNbonded thread. Since the adjustment, it seems to be doing fine with long stitches in reverse. (Not bisecting the thread anymore.) It makes sense that if you must optimize for either forward or reverse, one would almost always optimize for forward stitching. But here's another avenue I have not used but am considering: "Set the hook-to-needle distance to zero for long stitches in reverse, and use the hook needle guard to keep the hook from clobbering the needle in all other scenarios." This might get us down to zero hook-to-needle distance in all scenarios. But we'd also be deflecting the needle (elastic deformation) a little bit on all but the long reverse stitches. I'd be curious to hear how others have achieved a satisfactory hook-to-needle-distance compromise on machines that can make long stitches in reverse.

How to always have the hook to needle distance be next to nothing? At first I thought the thread was shredding when I stitched in reverse with long stitch lengths. (Thread is Selric brand TEX 135 UNbonded polyester) (Machine is Jianglong 341 (clone of Juki 341 but with even longer stitch lengths)) On closer inspection, the thread wasn't being torn actually, but in reverse with long stitch lengths (about 8mm) the hook was not catching all three strands of the thread. It might catch one or two. Here are some photos (recreated) of what it can look like when the hook tries to bisect the thread. Then I will continue my question in the next message..

Perhaps you could post a video of the walking foot in action so we can diagnose

I had the same problem on my pfaff. But spurred on by your question, I searched ebay for industrial sewing rubber mount These look like a potential match. Not sure if they match the carved-out spot in your table or not: https://www.ebay.com/itm/143924157971 https://www.ebay.com/itm/303681096346

Here are some additional photos and measurements that may show what's going on. Before taking these photos, I verified that the the top feed cam timing was correct based on pp 15 of the Juki 1341 engineer's manual. Then I set the needle even with the throat plate, and took these pictures first with the hinge bolt at the bottom of the banana slide, and then with the hinge bolt at to top of the banana slide. I conjecture that the design length of the top feed cam rod, combined with the radius of the arc in the banana slide are supposed to be such that sliding the hinge bolt from one end of the banana slide to the other does not actually move the upper feed driving shaft. (Assuming correct top feed cam timing, and assuming both presser feet are against the throat plate.) But on this machine, it DOES move the upper feed driving shaft. That is, starting at the first photo (both presser feet against the throat plate, and needle at the throat plate, and verified balanced lift height) then sliding the hinge bolt to where is shown in the second photo, the upper feed driving shaft moves away from the main shaft, lifting the vibrating presser off of the throat plate by 5mm. BTW this is a Jiang Long 341, which is a clone of Juki 341N.

Thanks for replying. Sorry I should have given more background. The engineer's manual for the Juki 341N (attaching photo of page 12) shows two separate adjustments: 1. Overall lift height 2. Balancing the lift between the two pressers The manual does not explicitly say If you adjust #1 then you will afterward need to adjust #2, otherwise your feed timing will be off and your lift heights will be unbalanced. But I wonder if maybe that is what is required... The first few times that I adjusted the overall height (1) based on the manual I was baffled that lift height was unbalanced afterwards, or that feed timing was off afterwards. Eventually I tried doing (1) then (2) in succession, and that seemed to give a good effect. But it also got me wondering if it's typical to require (1) then (2) in succession, or if there's something else out of adjustment just on my machine that makes it require this two-part adjustment.

When I adjust the overall lift height using the banana slide (A), do I also need to set the needle point flush with the throat plate and then momentarily loosen the bolt (B) in order to restore equal lift between the walking foot vs the presser foot? Somehow I assumed the banana slide (A) was all that was required to increase/decrease overall lift, but if I only adjust at the banana slide then afterward one foot lifts much higher than the other. This is on a clone of a Juki 341.

@FDC Will you post a photo of the motor pulley you're using?

Can we see a photo of the connector that plugs into the controller? You can slide the rubber shield back so we can see the individual wires. Want to make sure none of the wires broke.