Uwe

Welcome to Leatherworker.net Stanislav! There are MANY possible reasons that top thread tension may not working properly. Please post some pictures of the back, hook area and underside of your machine - it may allow us to narrow down what model your machine is. It's not a standard Pfaff 545 - of that I'm quite certain. Your machine looks like a two-needle machine that was converted to single-needle. Your thread tension assembly is also a dual needle tension unit with parts removed. The thread tension unit on my single needle Pfaff 545 looks like this (also Pfaff 145 and Pfaff 1245): On the two-needle thread tension units the tiny pins inside the post that push the tension disks apart are NOT the same length. If the tiny pins get swapped or the wrong length is used, they will not work right (I just worked on a two-needle Pfaff 120 where exactly that was a problem.) Make sure your tension disks are not permanently pushed apart by a pin that is too long. The tension disks have to press against each other to put tension on the thread. Make sure the threading is correct and that all the thread tension parts actually work the way they are supposed to work. The top thread may get caught somewhere and cause it to get pulled and loose tension. Open the right slide cover and turn a few stitches by hand. Observe the thread getting wrapped around the hook - it should be smooth, not snapping. I made a video with a Pfaff 1295 post bed machine recently. The Pfaff 1295 post bed machine has a different bed than yours, but the top portion of the head and the hook are the same as the Pfaff 545. The threading, bobbin loading, and thread tension release (pushing the tension disks apart when lifting the presser feet) should also be the same as your Pfaff 545. Some tension release parts on the back of my Pfaff 1295 are customized, but the effect of pushing the tension disks apart and letting them close again is the same (see 7:58 mark in the video below.) Make sure your tension unit works the same way when you lift the presser feet - your tension disks may be stuck apart for some reason. Here's my Pfaff 1295 video - compare top and bobbin threading, thread tension release, and hook movement to your machine.

I'm not aware of any clones of the DA 269 design. The 269 series is still in production, so you can get original DA parts (the 269-20-00-10 throat plate should come in under $200 retail). College Sewing the U.K has a few 269 parts listed as well, including throat plates and feed dogs. Kwok Hing makes some aftermarket parts for the DA 269, including a standard feed dog and throat plate. KH parts are usually nice quality and considerably cheaper than OEM.

Nice machines! There's a topic discussing this machine That topic mentions a general price range of $2000-$3500, depending on condition. With machines that hefty, location also factors heavily, so to speak, since shipping will be an issue. Just like real estate, they are worth precisely whatever a buyer is ready, able and willing to pay at the time you put it up for sale.

Well, somebody got the Singer 97-10 for $743. Good for them! I have parts, if they need any.

Sounds like something I would say, too.

The are no new machines in that class and price range unless you live in southeast China. The cheapest new machine (short-arm 441 style machines) that covers your application range in the U.S. runs about $1,600 before shipping. You may be able to find a used one if you're extremely lucky. Without knowing where you live, it's hard to make more specific product suggestions.

The Adler 167/67 model brochure leaflets (Leaflets_Adler_Class_67_part2.pdf ) show this machine on pages 15/16. There are seven different sub-classes that belong to this group with slight variations in technical details. The big hook makes it one of the "167" models. The Adlers are generally very nice machines.

A simple inquiry to the Oracle on Mount Ebay (a.k.a. search for "Juki 241 feet") reveals listings that suggest that the Juki DNU-241 shares feet with: ARTISAN : 618-1, 4400RB BROTHER : B837 CONSEW : 206RB, 225, 226, 226R, 277 JUKI : DNU-241, DNU-1541, LU-562, LU-563, LU-1114, LU1508, LU-1510, LU-1560 MITSUBISHI : DU-100, DU-105, LU2-400, LU2-401 SINGER : 111G, 111W, 153K101, 153W101, 153W103, 168W, 211G, 211U, 211W TACSEW : T111-155 YAKUMO : 260L

Probably not. The flat-top plate and the standard curved throat plate have the same thickness in the middle.

If you're worried about pitfalls and condition of used machines, get a brand new Consew 206RB5 with a servo motor from Miami Sewing. It should be very close to your price target (you can get one shipped from California for $1350 on Ebay so local pickup hopefully will be a cheaper.) The Consew 206RB5 is a very good, capable design and a great starter machine. Having a dealer and service option within driving distance is a big deal. Go local if you can.

I'm not sure. Some of the Ferdinand Bull machines are modified original Juki TSC-441 machines which may accept this plate, but other Ferdinand machines are not compatible.

That Durkopp Adler 272 is a fine machine for its intended purpose, but being a good starter machine for sewing leather is not its intended purpose. The 3-phase power requirement alone rules it out for nearly all domestic settings. This Juki LU-563 is an example of what many people here on LW want to own and work with: https://miami.craigslist.org/pbc/hvo/6013897271.html These machines are very capable and well made, cheap parts are readily available and the servo motor provides good low speed control.

I finally found some screws (Juki part number SS-6121050-SP) to install this throat plate on 441 class machines without requiring washers:

Now I'm curious how you defied gravity on your machine! Would you mind starting a new show-and-tell topic in the leather sewing machine forum telling us what you did?

Nice work 1CJK, looks very solid! One drawback with having the lever point down when the feet are up is that you can't lower the feet again using the foot pedal (while holding the material in position with both hands), because the lever won't "fall" back up to the normal position. But that matters only if you're even using the foot pedal release method. There are many options, you just have to pick one that works for you. Thanks for sharing your solution!

I made a small batch of the extension lever that replaces the original manual foot lift lever on the Juki TSC-441 class of machines, which include Cobra Class 4, Cowboy CB4500, Techsew 5100, and many others in that same class. The main advantage is that you can use it along with a swing-down edge guide like a KG-967 or KG-867. The original lever gets in the way. I call it UX441 and I'm selling it to the general public on Ebay for $59 (http://r.ebay.com/sVhPDU) LW members get $10 off, just send me a question through the Ebay listing and tell me your LW member name. You can also contact me via personal message (PM) right here on LW to avoid Ebay. For folks outside the U.S., shipping really is cheaper if you go through Ebay. Of course you can make one of these yourself if you're handy and motivated. Here's a picture of my UX441 version with fancy packaging and a cute red dot. Here's the promo video I made for the extension lever:

It's unlikely that thread tension is the culprit. Normal polyester or nylon thread doesn't usually break the thread guides. Some specialty threads like Kevlar on the other hand will saw right through metal guides and take-up levers over time. Sometimes the needle bar height is set too low and it may touch the presser foot when the foot is raised. I've worked on several machines where the needle bar was set too low. It happens if hook timing is a little late and the needle bar is lowered to compensate. Most machines have a sweet spot where hook timing is spot-on and the needle bar clears the raised foot by a fraction of a millimeter. Using the wrong or a poorly made foot may also cause the needle bar to touch the raised foot even if the needle bar height is set correctly. If the needle bar touches the raised foot, running the machine at thigh speed with the presser foot raised up (e.g. to wind a bobbin) will slam the bottom of the needle bar against the presser foot repeatedly. That can cause the thread guide, which often extends a tiny bit below the bottom end of the needle bar to get fractured and break over time. Make sure your needle bar does not touch the raised presser foot before you install the new thread guide.

I really do think the fix was a normal adjustment and I don't see any indication of some major flaw that needs to be worried about.

I vote for letting the man enjoy his stutter-free machine.

I think the vertical plate adjustment is just a normal adjustment for this machine's design and does not indicate a loose bushing or some other defect. The bearing wheel presses against the vertical surface as it rolls up and down. That vertical surface needs to be in the right plane to keep things aligned properly and provide a leverage surface for the bearing wheel. If the vertical surface is too far away the linkages put horizontal pressure on the presser foot bar and deflect it or press it sideways against the upper and lower bushing walls, rather than guide it straight up and down without sideways deflection or pressure.

As a follow-up, I actually caused a similar problem on my Adler 205 once, where the foot lift linkage started making odd clicking noises. I took me a while to realise where the noise came from and that I myself had caused the machine to make these noises after adjusting the manual foot lift height. A very subtle tweak to lower the manual foot lift height a small amount brought the machine back to silky smoothness and banished the clicking noise. In my case the clicking noise was caused by an internal sliding block that was stuttering as it moved on the shaft. The Adler's mechanism is different enough from your 441 class machine to not be of help in debugging your case. I'm just mentioning it to illustrate that small adjustments can have unintended side-effects, and that some issues only manifest themselves at very slow speeds and could easily be missed during initial setup. The clicking noise actually went away when speeding up the machine. No off-center holes or lemon castings, just plain old user error was the root cause in my case. Here's a video snippet of my Adler 205 making the clicking sound:

I'd take the faceplate off and carefully observe how everything moves as you slowly turn the hand wheel. Give it a good oiling while you're at it. You might be able to tell where it catches and causes a stutter. Sometimes the foot lift linkage needs to be adjusted a little to line things up just so for smooth movements. Also check if a screw may have worked itself loose during the break-in period, which happens on occasion with new machines no matter how careful the technician is. The vendor's tech support is your first line of problem solving, be sure to keep trying to give him a shot a fixing your problem. The dealers keep saying that it's their setup work, initial adjustments, and after-sale support that makes the difference between all these virtually identical clone machines. If you're going to end up doing the work yourself, you might as well order a machine on alibaba.com and save a chunk of money up front. At the same time, even the best vendor has absolutely no control over which screws the user turns, which may cause issues. It's not yet time to lose sleep over potential off-center holes and lemonade. But it is time to break out the camera phone, dust off your youtube account (or get one) and post a video snippet of the problem. The only thing that's certain is that this won't be the last time words alone will not sufficiently describe a problem.

A variety of factors may affect stitch length as material thickness changes.The pendulum effect by itself accounts for less than 0.5mm of the 2mm you're losing. Sometimes the feed dog movement isn't quite right and it only manifests itself with thick material. If the feed dog descends too early or rises too late, it may affect stitch length. With thin material it may be less noticeable since the material gets pressed into the throat plate opening to make contact with the feed dog even if it's a little off. If there's significant drag or friction at one or both ends of the material feed movement, it will affect stitch length. Ideally, the inner presser foot arrives at the material at the same time as the tip of the needle. If it's far off, it may affect stitch length. That inner presser foot timing may also need to be adjusted a little if you sew very different material thicknesses. How squishy or stretchy the material is also plays a role. A little high school geometry math (or a CAD program) will let you figure out what the pendulum effect itself may contribute to the theoretical change in stitch length. It contributes surprisingly little, actually. On a 562 class the needle bar pendulum is roughly 9" long. If the needle "swings" an 8mm (0.315") stitch length at the throat plate level, it will swing a 7.54mm (0.297") stitch length at 12.7mm (1/2") above the throat plate. So theoretically the pendulum effect accounts for less than 0.5mm in shorter stitch length if your material is 1/2" thick. This image is a screenshot of the very bottom of the pendulum in my CAD program, showing the two stitch length measurements at throat plate level and 1/2" above:

The only time I really noticed the lack of vertical feed dog movement on my Pfaff 335 was when the material had a step on the underside due to a fold. The feed dog would catch on the step as it moved towards the front and push the material towards the front as well, resulting in short stitches.

If you can't find brochures, manuals, or documentation that list specs and describes how the thing works, don't buy the machine.