Uwe

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.

Search Ebay or Amazon for “1245 feet” and you’ll see dozens of presser foot options that will fit your machine. Look for feet with at start with “KP” in the part number, they’re good quality feet. Pfaff models 145 146 195 335 345 540 545 1240 1245 all use the same feet. Almost nobody shows Pfaff 345 in their listing description. You can also order good quality parts directly from a manufacturer at http://khsew.com (search for “1245” to see feet or “345” for throat plate and feed dog.) Thread path looks okay from what I can tell on those small pics. I’d recommend tweaking the hook timing a little to see if it makes a difference. Very often a small adjustment makes all the difference between snapping thread and buttery smoothness.

The Sailrite machines are okay for certain projects, they’re even perfect in certain situations (e.g. repairing a sail on your boat in the middle of the Atlantic). They are comparatively cheap and certainly portable. They enjoy great marketing. But you get what you pay for. They are not on the same level as other true industrial machines in terms of design and build strength.I doubt you will find a Sailrite in an actual factory (save for the occasional car upholstery shop.) If you can make them work you, then you can a save a little money and a lot of space. Alas, you won’t find too many glowing reviews of Sailrite machines here on LW.

There are a few things going on here that don’t seem quite right. The main issue may indeed be a hook timing issue. It seems like the thread snags on the tail end of the hook gib (called the cast-off nib) because the hook is a little too late letting go of the thread. Advancing hook timing a little, i.e. making the tip of the hook arrive at the needle a little bit earlier may help with that issue (because the hook gib will also let go of the thread a little earlier.) Essentially the take-up lever is fighting against the hook. This photo points to the cast-off nib: This video show the same problem on a different machine (caused by a retarded hook timing). In that case advancing the hook timing resolved the issue: Your top thread tension also appears to be excessively high. Especially in reverse the top thread pulls the bottom thread straight to the top and then some, despite the leather being pulled up with the thread. Check your upper thread path to make sure it’s right. The presser feet are not doing a good job holding the leather down close enough to the needle as it pulls the knot tight. The left toe foot is too far away from the front foot and needle. If the leather gets pulled up while it’s trying to pull the knot into the leather, that normally causes the knot to stay below the the leather. On your machine the knot gets pulled to the top anyways. Please take some photos of your thread path.

The Juki LU-1508NH may be a machine that can cover the projects you describe. The original is available from Juki and there are clones/copies of this design available under various brand names. There are several versions of the basic 1508 design (N, NS, NH, etc.)- you want the NH version. It may not be the cheapest design, but it sure would be cheaper than two separate machines. Since you have space limitations, this might be a good candidate to investigate. The video below shows the Titan branded clone, and they demo sewing both Tex70 and Tex277 thread, very few machines can handle that wide of a range. That should cover wallets to belts and likely knife sheaths, depending of what type of leather you intend to use. A good servo motor and speed reducer will be essential. Artisan is another clone vendor. They are based in California and call their version the Artisan 1508-10H: http://artisansew.com/walkingfootmachine.html Perhaps Artisan are in day trip distance from you. Buying a machine from a local-ish dealer is kind of a big deal, especially when it comes time to service it. Being able to try out the machine and pick it up in person is just priceless.

You’re not far off now, it seems. I don’t see or hear anything glaringly wrong other than perhaps some thread snapping perhaps due to the hook gib not letting go of the thread early enough (advancing hook timing might resolve this.) Please elaborate on what you actually do. “I adjusted the stitch length adjuster” doesn’t really give us enough information about what you actually did. Which screws did you loosen, what parts did you move in which direction? Others reading this topic in the future will want to know what to do, or what not to do. I’m not sure what manual you get with the TechSew, but the Juki LS-341N Engineering manual describes how to balance forward and reverse stitch length on pages 14 and 15 (see images below). The TechSew may be a modified/enhanced clone since it apparently can do 9mm long stitches. The original Juki LS-341N can only do 6mm. I have a feeling multiple planets have to align and all relevant adjustment have to be spot-on to squeeze 9mm stitchlength out of that design. I’d be curious to know how TechSew accomplished that. Make sure the feed dog movement is perfectly centered in the throat plate opening. At 9mm stitch length there is no wiggle room at either end (unless they use a significantly shorter feed dog.) Below are the two relevant pages in the Juki engineers manual that describe how to balance forward and reverse stitch length and adjust feed timing. Your machine may not have the engraved markings the Juki manual refers to. It would be interesting to see if and how the TechSew manual differs from the Juki manual.

Well, it sounds like at least one adjustment is not at the factory setting. Which manual were you using to make the adjustments? It’s hard to offer advice without knowing what you actually did to the machine and without actually seeing what’s going on. Pictures and video help. I also wonder why the bobbin case opener needed to be replaced on a brand new machine. I strongly recommend NOT running the machine under motor power until you get it adjusted right. You can do a lot of damage in a matter of seconds if you run it under power while something is loose or adjusted incorrectly. Remove the motor belt until the machine makes perfect hand-turned stitches. Don’t take it personal, but there’s a good chance that you inadvertently caused most of the problems you’re experiencing with the machine. Getting your machine back to a working state may not be a simple task.

Single toe feet are useful for sewing very close the edge or when using an edge guide, and also for sewing zippers or near an edge or step.

The knocking sounds may come from a loose connection or play in the feed eccentric mechanism. If the feed eccentric is not adjusted to be snug, parts may shift against each other as they turn, creating a clicking or knocking sound. I’d recommend inspecting the feed eccentric on the underside of the machine to see if there’s any play in mechanism. The feed eccentric has adjustment screw that allow you to make the movement snug and smooth. Here’s a video that shows how you can adjust the eccentric assembly to make it snug: Here’s a video that shows that assembly by itself and how it can create clicking or knocking noises, essentially the same info as above:

Sewing sheep skin on a domestic sewing machine like the Singer 70R8 may be an exercise in futility, meaning it’s unlikely to work well, no matter how you adjust your machine. The bottom-only feed machines often struggle to feed multiple layers of material evenly. Sewing skin-on leather like sheep skin and fur often requires specialty machines to obtain satisfactory results. The hair makes it difficult to keep the two layers aligned and feed them uniformly. This video shows the type of sewing machine you’ll need to sew Sheepskin with professional results. They’re sometimes referred to as Bonis or Strobel machines, two of the major manufacturers of these types of a machines.

If the thread snags for some reason at any point during the stitch cycle and pulls more thread from the spool, it will be impossible for the machine to pull the knot tight, regardless of needle size or thread tension settings. Take some pictures or better yet post a video snippet via YouTube so we can see what’s going on. The problem with you telling us what you see is that you may not even know what to look for.

I just spent some quality time with my own Cowboy CB-3200 to figure out how that walking foot linkage works, and how it should be adjusted. The Juki TSC-441 engineering manual doesn’t really address this for some reason. I made a video that shows how I adjusted my machine and the small modification I had to make to avoid a bind in the linkage. Hopefully it gives you enough information to adjust your machine as well.

To get somebody’s attention here on LW, you have to use their handle like this: @Uwe (type the @ followed by the username and then select the handle from the drop-down menu). Otherwise it’s just coincidence that somebody reads your post. Usually the good-forward but bad-reverse is tied to hook timing. Forward stitching is much more forgiving compared to reverse due to the relative movements of hook and needle. A machine that makes a nice stitch in reverse will nearly always make a nice stitch going forward. The converse is not always true. Noise usually indicates parts touching or thread snapping. Make sure that hook timing is spot-on and that the needle guard is actually touching the needle at the moment of hook timing. Also make sure that the bobbin case opener actually does its job. A few very slow hand-turned stitches while observing thread , needle, and hook usually tell me all that I need to know. I usually set hook timing by the book for forward first, then I tweak hook timing slightly (advance/retard) to also make it also work smoothly for reverse. I don’t have a Pfaff 345, so I can’t check directly, but I am guessing the hook mechanism is very similar to that of the Adler 269 or Juki 341. Pictures and video snippets linked via Youtube are always a great help. Practice that to increase your odds of meaningful remote crowd-sourced service advice.

Those loops at the bottom indicate to me that the thread snags somewhere during the stich cycle and the machine never gets a chance to pull the knot tight. Usually that has to do with either hook timing, burrs, or the bobbin case opener function. Double-check your thread path and do a few very slow hand-turned stitches while observing how the thread gets wrapped around the hook. If the thread snaps or snags anywhere, that’s what you need to fix. If the machines pulls more thread form the spool in the middle of the stitch cycle, that’s a sure sign of trouble. The machine should ONLY pull thread form the spool when the thread take-up lever is at the very top of its movement.