Uwe

I think it’s better to know what’s broken than to get frustrated with a machine that’s not working properly without knowing why. Hopefully that new thread tension release slider will fit and your foot lift and clearance issues will be resolved. Perhaps this was why the machine was for sale in the first place. Kudos for getting all that disassembled, that was not a trivial task! On the plus side, it’ll give you the chance to give the disassembled parts a good cleaning and remove gunk from the works. It also is good to get to know your machine at that level and gain confidence in handling service and repair tasks yourself. Let us know if you run into trouble putting things back together. It takes some patience to line things up properly inside the tight space. It’s okay to just let it sit for a while if you get frustrated with it. Then try again. Hopefully by the time you’re done you’ll feel good about the machine working the way it’s supposed to and having done the repair yourself.

I still think the issue has to do with hook timing and not needle size, although it may be a combination of factors. It looks to me like the hook arrives a little too late at the needle. This causes it to be slightly out of synch with the the take-up lever movement. The still frame below shows the moment where I think more thread gets pulled from the spool. The thread is taught everywhere and the check-spring is overpowered and maxed out. The thread take-up lever has already started going back up at this moment. At this point it does not matter what tensions setting you have dialed in, thread will get pulled from the spool no matter what. Every millimeter of extra take-up arm movement pull two millimeters of extra thread from the spool. That excess thread will later prevent the knot from getting pulled into the material. This still frame below is taken at the moment the needle is at bottom dead center. The tip of the hook appears to be near the 6:30 o’clock position. It really should be near the 7:30 o’clock position (needle is at the 9:00 o’clock position) I made a quick handheld video showing the stitch cycle on my Juki LS-341 in a slow motion hand-turned stitch. Hopefully it will allow you to compare my stitch cycle timing with your machine. My recommendation would be to advance hook timing by about “5 minutes on the clock face” and see if it helps.

Thanks for the pictures and videos. Posting pictures right here in the forum is the best way for easy in-topic viewing and also for archiving purposes. That Google drive link will just not work a year or two from now, and the search engines don’t index the photos unless they’re actually on a web page. It’s a bit of a pain to resize photos to upload them here, but well worth the effort in the long run. There are quite a few adjustments that are not quite right from what I can tell based on your videos: Top three issues that need to be corrected first: 1. Hook timing looks retarded, meaning the hook arrives at the needle too late. This causes the needle bar to be set lower than it should be, and it causes the thread to snap around the hook because the hook timing is not properly synchronized with the take-up lever motion. This video shows how to time the hook on this class of machine: 2. The walking motion of the feet is not timed correctly. The front/inner foot arrives at the throat plate much too late. This video shows how to adjust the walking foot timing on a Pfaff, your machine works the same way: 3. Your rear presser bar is adjusted too low. This causes your foot clearance issues. The video below shows a lengthy repair that you DON’T need to do. During the re-assembly steps it shows how to adjust the rear presser bar height starting at the 11:35 mark (use a 1/2” spacer block for your machine) You’ll need to back out the presser tension screw (shown at 1:00) and loosen that clamping screw I’m tightening in the video to be able to move the rear presser foot bar up and down. Report back after you’ve made these adjustments and we’ll address the other issues. We’’ll need to see how various parts are aligned with the needle in three key positions: 1. When the descending tip of needle is level with throat plate. 2. Needle at lowest point (bottom dead center) 3. Needle in hook timing position

Please post some pictures of your machine. That model apparently went through multiple versions and castings over the years. There are surprisingly few pictures of this Seiko model available online. Suggested pictures: whole machine front and back, remove left cover plate on head and show internal bits, underside of machine with close-ups of hook gears, head near take-up lever and tension unit, close-ups of needle area, rear of machine near lift lever. Having pictures eliminates much guesswork and allows us to identify what version of the machine you actually have. Plus, we can mark up your photos with arrows as we try to explain things. A video clip uploaded to YouTube with a link to it posted here is the best way to show problems in motion. Extremely slow, hand-turned stitches tell the best stories. The feet on your machine may be cheaply produced aftermarket feet that are simply not to spec, off-center, or with a misaligned mounting hole, causing mis-alignment of needle and foot. If the needle is nicely centered in the hole of the feed dog, then the presser foot itself is a suspect. Show us how high the rear foot lifts above the throat plate when using the manual lift lever - hold a small ruler next to the foot. Show us a picture (or video clip) of the position of the tip of the hook when the needle is precisely at the lowest point. Hook timing variance may cause trouble, even if the machine manages a nice stitch. Show us a photo of the needle package you’re using.

Mine is a three needle machine and I gave up on getting it going. It sits patiently in a 40’ storage container full of vintage sewing machines and parts. The key to that storage container is for sale.

Check out the Leather Hide Store. They have lots of upholstery type leather: https://www.leatherhidestore.com/leather-for-upholstery I’ve ordered from Maverick Leather before. They often have interesting leather in their clearance section, in case you’re just looking for one-off projects. https://maverickleathercompany.com But this leather supply discussion really belongs in a different forum.

The rotary converter is just a separate device that plugs into your 220V outlet (like an electric clothes dryer or range type outlet - every house in the U.S. has 220V available in the circuit breaker box.) You may need an electrician to install a 220V outlet in your work area. Plug the phase converter into that 220V outlet and then you just plug your sewing machine into the outlet on the rotary converter. You may have to change the plug on the sewing machine power cord to match the one on the rotary converter, which is fairly simple to do. This screen shot from a video gives you an idea of how big the rotary phase converter is in the portable configuration. It’s essential an electric motor/generator and a box with electronics. Other configurations have the motor sit on the ground and the box with the electronics mounted on the wall. Same function, just a different configuration. I have mine mounted on a small moving dolly so that I can wheel it around and use it in different rooms. They are quite heavy. Aside from the rotary phase converter, you’ll also need a compressed air source for the pneumatic system. I use a small, relatively quiet air compressor and it works just fine. Some cheap compressors are very loud when they’re running. I recommend one that similar to this California Air compressor pictured below. Similar models are available at hardware stores like Home Depot or Lowe’s.

You can manually oil the machine, that’s not a problem. The automatic oiling is just a small reservoir or pan that sits under the hook. The pan usually has a sponge/felt inside and is filled with oil. With that reservoir installed, the bottom of the hook shaft dips into the oil. There’s a spiral grove in the hook shaft that moves oil up to the bushings, but only if the bottom of the shaft sits in a pool of oil. The oil gets flung to the sides by the rotating hook and hits the black metal side shield you still have installed on your machine. From the side shields the oil drips back down into the reservoir pan. The sponge/felt just traps dirt to prevent it from getting sucked up by the hook shaft. You can make your won oil reservoir if you’re handy - it’s just a rectangular box, nothing special. But you don’t really need it unless you sew at full speed for several hours at a time. For hobby use, a quick manual oiling before you start sewing is fine. This page from the Juki LU-563N Parts Manual shows the oil drip pan (part 56) which normally attaches to the table. Don’t disassemble anything unless you have to, or you know what you’re doing. A good cleaning with a cotton rag or tooth brush and some oil will likely get things moving very nicely. I wouldn’t recommend using a chemical paint stripper on the machine unless it’s totally disassembled. Just scrape off the flaky bits and use some sand paper to smooth the edges. Use a vacuum to pick up the sanding dust to keep it out of the moving parts of the mechanism. There’s a few topics on here where people discussed re-painting their machines. Getting 3-phase power installed (or getting a rotary phase converter) may be more expensive than getting a brand new 230V servo motor. If that 3-phase motor is a clutch motor, I’d recommend getting a new servo motor. Best of luck with new machine! The Juki LU-563 are a really nice design and should last a long time if you take care of it. Here’s a video that goes over some basic adjustments on these machines:

That depends on which motor and controller you install. If you Install a $1,000+ modern EFKA motor and controller like the EFKA DA321G (https://www.efka.net/en/products/control-box/da321g/) or other high-end system that is designed to be used with this machine, then the automation functions likely can be made to work. It won’t be a trivial undertaking and you still need 220V. If you install a basic sub-$200 servo motor, none of the automation functions will work, and you will have trouble operating basic functions like foot lift or reverse, because the machine is configured with pneumatic cylinders to perform those function via switches and valves. There may simply be no manual reverse lever, for example. I have on of these machines and built a rotary 220V 3-phase converter to run it. Works like a charm and is a joy to use. Ready-to-use rotary phase converters like the American Rotary AR-5 run $475. Not exactly cheap, but you can run the machine the way it was intended to be run. Cheap static 3-phase converters do NOT work in this application, I tried. If you install a basic motor without automation functions, it’s still possible to add pneumatic switches to control functions like foot lift and reverse manually via pedal or knee switch. I used a pneumatic switch that replaces the pedal linkage to add pneumatic pedal-heel foot lift functionality to a machine once. In any case you’ll need a small air compressor to operate any pneumatic features of the machine. Here’s a sewing demo video I made with my machine a few years back running on 220V 3-phase, just to show you how it works in full-function mode. Also, make sure you read this topic - it contains a lot of wisdom about the Adler 467:

The manual for the Consew 18/118 might be useful: https://www.manualslib.com/manual/1273358/Consew-18.html Here’s previous topic on the Consew 118: The threading is the same as the machine in this video:

The Consew 2206RB-14-7-DD looks like an interesting, fully integrated machine. I’d never even heard of it before today. It certainly looks impressively big and makes a nice stitch in the various YouTube video demos. The only downside I can extract from the spec sheets is that it’s Top+Bottom feed only, no Needle feed. Not a show stopper in itself, just something to be aware of before pressing that buy-it-now button.

I’m just speculating here, but it looks like Pfaff changed their serial numbering scheme some time in 1967. The serial numbers in the chart above jump from 9,000,000 in 1967 to 29,000,000 in 1968. It’s unlikely that Pfaff suddenly produced 20,000,000 sewing machines in 1967. The change in serial numbering may have prompted a change in how they are marked on the machine. Perhaps the full serial number is now split between embossed casting and a stamped plaque. Perhaps the plaques were a transitional method until they finalized the new numbering scheme. Some manufacturers didn’t assign a serial numbers until the top casting was joined to the bottom. The various parts were, well, just parts, and they didn’t become a serialized machine until the major parts were joined together. The same top could be joined to flatbed, post bed, or cylinder bed, etc. to make various machines. In any case, I suspect that both of your machines are of late 60’s vintage. Just the paint color rules out anything pre-1940 in my book. Nearly all sewing machines were black until the 1930’s. Little happened in terms product development in the 1940’s due to the war. Then they got production going again in the 1950’s and started experimenting with colors other than black. Perhaps somebody will stumble across some information that allows us to make full sense of your apparent serial number plates. Until then, just enjoy your vintage machine as it is.

The short answer unfortunately is “No, you can’t get there from here.” You probably mean the Juki CP-180 control panel. The CP-180 control panel only works with specific Juki OEM motor controllers on machines equipped with full-function features. The external control panels are just a convenient user-interface to change motor controller setting (essentially an external keyboard and bigger display.) The control panel itself does not add any functions to the machine, it just make it easier to control existing functions. For example, installing a control panel that has back-tack buttons would not add that feature to the machine. In general, everything you can do on the external control panel, you can also do directly using the buttons and display directly on the motor controller. Conversely, if the motors and control can’t already do it, adding the external control panel does not help. So, unless your machine already is a full-function machine with pneumatic or solenoid-driven actuators and the OEM Juki motor controller (your LU-1508 is NOT one of those machines) then looking to add the CP-180 control panel makes no sense. This Juki Series 1500 product sheet shows which models are available with full-function options (Juki usually uses the -7 extension in the model number): https://www.juki.co.jp/industrial_e/admin/pdata/filedata/333/lu1500n.pdf Adding automatic thread cutting capability to a basic machine is also not a practical option because the feature requires several other automation options to be present as well. You can have automatic back-tack without a thread cutter, but you cannot have a thread cutter without automatic back-tack. If you need these automation functions, your only practical option is buying a full-function machine that already has all that (e.g. Juki LU-1510N-7.) Attempting to add full-function features to a basic sewing machine is not a practical undertaking (there are some rare exceptions for machines that are “prepped” to add automation features with upgrade kits after the machine leaves the factory - the Durkopp Adler M-Type 867 comes to mind.) One “easy” automation feature you can add to a basic machine by means of a servo motor is needle positioning.

That plate number in your picture may not be the serial number. My Pfaff 545 has the serial number stamped directly in the casting: The serial number 8435866 on my Pfaff 545 dates it to 1965, according to this Pfaff Serial Number Dating chart I came across long ago:

I’ve not seen a service manual dedicated to the Pfaff 545. Here’s a past topic that goes over certain adjustments for the Pfaff 545 and also has a link to a Pfaff manual with a service instructions supplement:

It’s not really the hook timing per se, but rather needle bar height that you need to adjust in order to change between the two needle systems. The tip of the hook arrives at the needle at the same correct moment, but the eye of the needle is not at the correct height if you change to a longer or shorter needle. To change needle systems in your case, bring the needle bar with the system 134-35 needle in it to the highest position. Measure or mark the height of the needle EYE above the throat plate. Then insert the system 190 needle and adjust the needle bar height to bring the needle eye to that exact same height. The machine should now sew as it did before. The H4 versions have an extended needle bar stroke. If you use the shorter system 134-35 needle, the lowered needle bar may touch the fully raised presser feet in certain situations, causing a bind. I’d recommend using the needle system the manual calls for unless you have a specific reason not to.

I suggested the 1508-10H because that’s the design I’d likely choose for myself if I were to buy a flatbed machine right now. There are hundreds of sewing machine candidates, both new and used, that have been discussed in thousands of topics here on LW. Some of the popular flatbed candidates are: Pfaff 145, 545, 1245 Adler 67, 167, 267 Juki LU-562 or LU-563, 1541, 1508 Consew 225, 226 Singer 111W155 Seiko STH-8B . . . And scores more. There are lots of clone options as well. A clone is essentially a copy of an original designs, manufactured by other companies after patents expired, and sold under various brand names. Common clone brands include Artisan, Cowboy, TechSew, Thor, Cobra, Typical, Consew, Titan, and many more. I recommend spending a little quality time on this forum. If a candidate pops up for sale locally, you can search for previous discussions on Google using a search term like this: ”Site:leatherworker.net Juki 1541”

I’d recommend a machine that had triple feed, meaning it has an upper walking foot, bottom feed dog, and needle feed, all feeding the material in unison at the same time. The 1797AB machine you’re considering only has upper and bottom feed, but no needle feed, according to spec sheet here: http://artisansew.com/pdf/specs/1797_AB_LTHR.pdf It’s workable, but not ideal. If you’re going to invest money to buy a machine that can handle your projects with ease, get the best you can afford. Unless you’re on a very tight budget, I’d go for a new machine like the Artisan 1508-10H. This machine is a very good design and won’t be struggling with any of the projects you mentioned. Perhaps plan a road trip to visit Artisan to try out the machine in person and potentially pick it up.

$300 for a Singer 111W153 head seems reasonable to me - if it‘s complete and serviceable. You’ll likely have to learn how to service the machine yourself anyways. It’s a good starter machine in that regard - they’re easy to work on. Common parts are generally still available for these machines and they’re cheap. Beware of sellers who have no clue about how to properly package a head for shipping. If you put a 70lbs head into a cardboard box with foam peanuts, you’ll all but guarantee that it’ll get destroyed during shipping. Find a local pick-up deal if at all possible.

We’ll need to see some pictures or ,better yet, a video (upload to YouTube, post the link here) of super slow motion hand-turned stitches of the hook area to have chance of figuring out what might cause your reverse stitch issues. Thread tension is only one of a dozen possible culprits, and not the most likely one.

I looked into using a VFD drive a few years back. I bought a nice VFD and a 3-phase motor and set it up on a test stand with a pedal for speed input. Alas, I soon abandoned that project - it was just not a practical solution in my mind. I highly recommend going the brushless servo motor route instead.

Yes, I added the red arrows to point at the part shown in your original diagram. The part they want you to rotate will be an eccentric bolt (an off-center bolt, it “wobbles” as you rotate it.) When you rotate it, you will in effect lengthen or shorten that connecting arm a very small amount. Mark the original position off the eccentric bolt with sharpie pen before you make any changes. This way you can move it back to its original position if you need to. Here’s a picture of what an eccentric bolt looks like The picture is NOT your exact bolt, just an example.

I don’t have the machine to take a photo, but this diagram shows where that part is located inside the machine. You’ll have to remove the top cover panel to get access to it.

Whoa, that planetary gear setup is quite something! The Singer 151W and also the Singer 108W are compact triple feed machines, weighing in at around 35lbs, compared to nearly 70lbs for the full size Singer 111W155. With a modular servo motor setup, you have a great deal of flexibility for arranging the components in a small table-top footprint. I replaced the motor on my serger with such a setup to make a compact, portable table-top solution for sewing masks. Works like a charm. A similar setup could be used for the compact Singer for a rather portable solution. The motor below is a 1,500W motor, way more powerful than you really need for this Singer. Just for illustration purpose a few pictures of a mock-up with a Singer 151K3. Imagine a cutout in the plywood box to sink the machine into. Lift the machine out for two-part transport, each piece weighing 35lbs or less.

The Singer 111W155 is the default choice for leatherwork. There’s a compact/stubby version called 151W which might be a good candidate for creating a luggable table-top setup. Quite capable for small projects like wallets, belts, perhaps even sheaths, I suppose. I have some in storage but I don’t have that bottom part shown in the picture for table-top operation. I’ve made similar table top setup out of plywood for testing full size machines.