Bugstruck

Well that's what three glasses of wine will do. Wiz is correct, my idea won't let the stitch form as the upper thread won't loop the core thread (bobbin). Hey, I was brilliant for about 30 seconds, in my mind only. LMAO now, at myselt.

Unless I'm completely missing something that 301 lockstitch and continuous bobbin feed thread path is fully achievable. Blows my mind nobody has figured it out yet. Not really a challenge compared to all the other machinery technology hurdles that have been long been cleared. Push the bobbin on a horizontal hook to the floor, then engineer the path. Barely difficult. Drive the hook from the side is the easy solution. With a gear under the hook and bobbin (as they all are now) it is rather more problematic but also achievable. Thread has to run the hook gear centerline in that instance, so a fight but surmountable.

135x17 is the same as DpX17 as I recall.

Found this. May be some help on the needle type. Start there. May have the right needle in it now and may not. Need the right needle to calibrate it. https://www.industrialsewing.co.uk/industrial-sewing-machines/needle-feed/necchi-840-136-industrial-cylinder-arm-needle-feed-machine

I really don't even know what say to that level of artistic ability. Yes sir, I am at a loss for words that are adequate.

Well you are reading info from the right guy. Wiz is a wealth of knowledge and good advice. If I come across as wise it is fully attributable to all the sharp tacks around here and the contributing machine vendors and real Leatherworkers who really know their stuff. Very helpful group of people and I'm thankful for what they contributed to my knowledge base. Always learning something new.

Luke, I would not part with that machine without giving it some serious thought. I had and still have old Singer home-type iron (cut my teeth working on and restoring them), then as my need to sew heavier products materialized, I got the Adler walking foot, then when heavier leather got in my blood the Cowboy 4500. Then I needed something less robust than either of them for wallet interiors and lighter work. Yep, needed a third machine and still looking. Believe me, they all fill a capability niche. Your machine and a heavy leather stitcher are a pretty good combo. Plenty the heavy stitcher is not well or at all suited for, even in leather. Certainly use it awhile before you unload it. You need a light to medium machine before you need any other, My experience anyhow. I'd learn and use that machine well before I got a heavy stitcher. Learning curve is fairly quick but what you learn on it will go a long way with other machines that are less set it and forget it oriented. Love my 4500 (Cobra would be the same) but even with all the prior knowledge I'd gained it took some getting use to. They throw a very wide range of thread and will handle a wide range of materials, very capable, so they take more time to learn what they like. Having good experience on yours will make that upgrade easier. Either way though, good luck in your endeavors.

Agreed with one caveat. Not all clutch motors feather well. One on my Adler just wouldn't, tried several things to fix that. The clutch on my 78-3 though is a dream to operate. A servo has nothing on it.

Your bobbin winder was for a leather belt setup I'd think. Haven't tried the new round belts, can't bring myself to it on vintage (leather belt) machines. Only appearance related here (others may like that look), they likely work fine and no doubt run cleaner than leather. I am not certain a needle position setup works with a speed reducer (I don't run any), ask Bob if nobody answers that. Speed reducer is best with a servo for speed control and penetration power as you know. However, my old Adler 67 flatbed with a small servo motor pulley, that setup works well enough for what I throw at it. Gets up to 1/4" vegtan on occasion but usually on the Cowboy at that thickness or more as it taps out at over 138 thread. The Adler wouldn't suffice for most pros in a volume setting for a couple of reasons but beyond okay for a hobbyist (me) with that small pulley setup. Something to consider. You could always add a reducer later and I don't see it as necessary until you are sewing thicker material and over 138 thread. Grab a few v-belt sizes if you are mounting a new motor and changing pulleys, I never seem to nail the belt length right the first time on a new setup. I'd also vote for less automation (needle position) if you are coming from hand sewing. Forces you to get familiar faster with the hand wheel and brake release. If you are like me you will not be a fan of a brake on any machine at the speeds we typically sew. Just an annoyance IMO but it does keep the needle parked, safety, maybe? I don't even buy the safety thing on an exposed belt. Perhaps of some actual use sewing fast on thin materials. I'd much rather hand break any machine.

Well that is a bit of a test for a that machine's ability to climb. I had that problem on a flat bed walking foot that was related to the feet not being balanced for lift so check that first. Inner and outer should lift the same distance or very nearly so. If that checks good your machine (others will be more familiar) may have an adjustment on the back linkage that will modify the range of lift. Solar will know. A mockup with scrap and a video of it sewing through the problem zone may help them diagnose. Rarely, I have to slow down and hand wheel through problem transitions, even on a well calibrated machine, giving it an assist and working methodically. Not sure if you sewed right to left but climbing that folded portion as the feet drop into that one ply ditch is closing in on the zone that give some machines more challenge than they want. The assist in that condition is to manually flatten that fold as the feet approach. Sometimes you can insert something narrow temporarily just before a step up and remove it as you work slowly through a tough spot. Give the leading edge of the feet a temporary (usually just one stitch) bridge to thicker material. I could get a machine less capable than yours, and otherwise incapable, over that jump usually. Someone else here always knows something I don't too. Good luck and expect a learning curve.

I recall a year or two ago coming across a German geotextile sewing machine, looking for something else. Was the size of a high ceiling room. All CNC programmable. Was circle sewing maybe 8 or 10 foot diameter tubing. Wish I would have saved the link. Most impressive I've seen online. Knowing CNC industrial equipment costs in wood processing, I would be surprised if that machine was less than $250K. The travel range or that sewing head was about unfathomable. Robotics. Most impressive I saw in person was as a teenager. Emblem looms at Lions Brothers. The sound was as impressive as the many bolts of fabric they had spooled up. Fabric was on the vertical plane. If I recall correctly one side had a low catwalk. I do remember a tech fixing a broken thread on the fly and my Uncle explaining it saved that emblem. I doubt those big machines are still in operation, all seems to be sewn on multi heads with the fabric horizontal now. The newer emblem machines, even the 24 head are much smaller footprint than they had there at that time. Was quite the operation. Around 1973.

Others who commented know this machine or variant, I do not. At say $650.00 though, based on the video and your comments, I would own it. You are correct. It is not close to a Cobra or my machine but where it works, it works. Just know what Gregg said is reality. The others have offered good advice too.

Is that 546 a double needle machine? Walking foot? This is probably not your problem but I'll toss it out as it may help someone. When feeding your problem fabrics, with plenty of material both sides of the presser foot, does the material self feed straight or does it want to sew and an arc? Doing close to edge sewing can sometimes be problematic. Bringing nylon into the equation doesn't help. Sometimes that is a stitch formation issue, not so much feed rate, although the nylon can impact feed rate somewhat, slippery. It should not be doing that to the degree you describe. What does occur sometimes, is that one paw of the presser foot sometimes contacts the feed dog plate before the other paw. This is usually more noticeable in thin material. Geometry is a little off on the outer presser casting (or feed dog plate a little bent) creating uneven paw contact and unbalanced pressure and drag favoring one side of the needle. Usually all it does is make the material want to turn instead of feeding straight and you can usually overcome that with how you control the fabric. When you have material under only one side/paw of the outer presser, you create a somewhat similar condition. I don not think that your feed rate variance issue is what I just described though. I'd guess you MIGHT have a small calibration issue between the walking foot center and outer presser that shows itself as the material thins up. Thicker material could mask that. My guess (if that were occuring) is the outer is cycling/lifting late. Before I'd go get into those weeds I'd play with presser tension first. Could be just that simple.

I don't think they carry Techsew parts. Been awhile since I've been active here but I believe Techsew or one of their dealers sponsors this site, used to. I'd certainly start there and if by some odd chance they can't get what you want you could PM me. You look to be a regular here, I think if one of the authorized vendors here sees your post, they would be inclined to assist. Someone here will know where to steer you rather quicker than I am presumably.

Call Bob, he may not have seen your reply.

On the exceedingly rare occasion I can't find what I need from the suppliers who take care of us here I try this outfit. Not confident this is what you are chasing as they list it as a stud and I don't think this is an eccentric but the part number lined up. Takes a while as they are across the big pond. https://www.college-sewing.co.uk/store/10634-SEIKO-STUD

All is well that ends well they say. Learned some things here too. I had a sense, when Clintok put that photo up of his stitching in response to Ferg, that he was going to beat this and somewhere in there he told us what he did for work and I knew for sure he had this beat in time, with all the good info being posted. I'm sure I wasn't the only one walking to my machine checking something and some here obviously did way more than that. What Rocky Aussie recently posted about the lower tension polish and oil. Well in the checking (radically altering) my machine upper tensions during this effort I noticed how choppy my lower tension was and thought that needs some attention. Oil on the felt crossed my mind but the polishing he recommends didn't, that will occur too now. Kudos to him and Wiz for some added things to check on bobbins going forward. Combined posts, this thread is an arsenal on clone tension issues. I think they only thing we may have missed and I may have missed that myself, is checking for any contamination below the bobbin spring. If it wasn't perviously it is now. I run that 180 degree thread path nearly all of the time on my top tension. Definitely helps keep the thread where it belongs.

Indeed, good looking holster work there. Hang in there, we've all wanted to kick our machines at times. The more you learn these machines the easier it gets but they can surprise us even then. Most of the time it is an easy find, not always. Two more items, don't think I mentioned in this particular thread?? 1. Make sure that after you wind the bobbin and cut the tail it pulls back in, get it flush at minimum. I've had a wayward tail (maybe 1/8" or a little more) chopping up the bottom tension once and that took me some time to spot it. I only had that once but I know what to look for now. 2. Be aware that sewing single ply, depending the nature of that leather and thickness, with the higher tensions we run at this thread weight, can cause an occasional stitch to pop through. Very rarely, unless doing decorative stitching, do I sew single ply. Others may know better on that. I do know two plys give the knot a better resting place. You pop it through or (nearly through is good and safe) the bottom ply and it has a place to park, between the plys. If you've ever sewn two layers of ballistic nylon you know that one could go bonkers trying to center a knot . Two on bottom, one on top, two centered, etc. That material is an exaggeration of the issue here but it is representative of what 1 ply sewing can sometimes create. Thinner the material, heavier the thread, and higher the tensions the more likely it is in my experience. When I rarely sew single ply leather I have the knot favor the bottom a little to mitigate pop through. You could back the top tension off until you just occasionally see the knot on the bottom, back the bottom tension off a tweak, not enough to re-center it or get you too far out of a workable range, and then move the knot around a little with top tension. If you reduce the tug of war and loosen the stitch a little it may help on single ply sewing, all else being correct. Worth a try perhaps? Are you getting occasional knots on top with two plys? You may have covered that and I missed it? Think you said 4-5 oz was the weight. I assume you are not fighting any frayed thread, correct? Didn't see any.

You are correct. These machines have a wide range of threads, materials and applications so you have to be more involved getting things where you want them than on many machines with a narrower range of ability. Basically I don't sew much below 207 thread on the Cowboy but it will go lower for sure. Think Wiz wrote how to dumb one down for the lighter threads. When I started out I had to try them all though, poor Bob. Waste of time except for what I learned about the machine, what it likes and doesn't and what materials it is best suited for. You will from time to time have to adjust bobbin tension. Get it sewing well at current settings and get familiar with how that feels. Once you get a sense of that you can move it around when you have too. Gauges and the like are fine but you would have to be recording all that and it may be a useful baseline but each sewing operation wants something a little different, unless the materials and thread are reasonably close to what was last sewn. So for me I want to feel it. If I'm sewing 207 or 277 on mine it would almost never need a bobbin tension adjustment, just where I have it set. Most of us sew predominately in a range of materials. That setting may even be good enough at 346 most days, depends. Drop to 138 though in similar material and it may (likely actually) need to be a tweak tighter for tension on the bobbin. My experience is while I can get mine to sew 92 without any trouble or radical top side adjustments (in materials I sew), I made some mods to the bobbin spring most wouldn't want to attempt and I sure don't recommend. I was new and hard headed, worked out okay but that could have gone wrong. And frankly, now it's a very rare occasion I run that light a thread through it anymore, even though I can. Bottom line is you center the knot and look at stitch tightness. If the tightness is off enough to matter, it's a bobbin adjustment followed by a re-centering of the knot with the top tension. The more you do it the easier it is and on the Cowboy it's an easy adjustment, just don't over tighten the lock screw on the bobbin spring tension screw (just very lightly snug it) and don't forget to loosen that same lock screw before adjusting the spring screw. The less you have to do this the better but again, there will be times. And you will learn how to put that lower tension in the range (sweet spot) for what is most often sewn. There are things on these machines and others better left alone but tensions are not one of them.

I was in the middle of a post and lost it. Tablet is squirrelly.... The wide range of thread our machines throw has an impact on tension release point. I usually sew 207 so that is what I was commenting, occurs fairly low. Run 346 and the release point is higher, closer to what we see on the narrow thread range machines. We ask a lot of these clones and they do a good job. What Rocky Aussie meant I think is the thread tension spring should seat on it's built-in rest just as the needle enters your material.

I should clarify, they do have a tension release delay but not as late in the lift as many machines. My experience.

You could try running the top thread through the upper tension then back through the eylete before descending to the lower tension. One of the clone vendors recommends that path to keep the thread well secured in the upper tension. I have had your experience and tried that alternate thread path with success one one occasion. The thread angle from the upper tension to lower looks agressive using that path but it has not caused me any issues.. Worth a shot. Sometimes the thread looks well seated in the upper tension but isn't. I don't know this but suspect the issue occurs when releasing foot pressure for turns or other reasons. The clones and presumably the Juki start releasing upper tension nearly as soon as the foot starts lifting, so you don't have a release delay there like many of our machines. Nothing wrong there, just how it is engineered, and the top of the discs stay tight which helps keep the thread where it belongs and engaged. Does ride up on rare occasion though and can give your results.

Susan, How thick is that leather and are you getting this on two ply sewing or only one ply? What needle size and thread weight? What needle point? Don't worry about the tang (as I called it). Thought you had a flat bed and don't think that applies to your machine. I am aware you may very well may have already done all this but just in case......This may not be a machine issue as some others observed. Assuming you've done most of my and Ferg's/others recommendations, I'd back the upper tension off until that bottom thread was laying almost flat, little or zero knot pull-up occurring from the top thread tension. Then walk the top tension up slowly and check and then some more and check, until you see bottom thread on top, then back the top tension off and see if you can get those knots to re-bury with any consistency and not flat line that bottom thread. Those knots may be popping through the top at random if the material resistance to the knot formation is not reasonably consistent. Other materials are more prone to your problem such as ballistic nylon where getting a consistent knot placement in the material can be difficult to unachievable (all material related and no adjustment will make it perfectly consistent unless you have enough plys). The knots may need to favor the bottom to keep from popping through in your instance. Single ply and thinner leather will do it and if the tensions on both sides are on the higher side (and thread larger as was mentioned earlier) it can add to that. You keep trying and so will we. Might even get one of gurus in here who sees something we haven't. Your in reasonably good hands but I can surely attest, a pro I'm certainly not. Some of these guys and gals have sewn almost everything on a very wide range of machines and seen about every variance and failure possible. Would be nice to see some more of them chime in as this one should not be quite this difficult to resolve.

Make sure you have enough foot pressure and that the leather isn't lifting. Simple as this is, make sure the bobbin thread is spooling off in the correct direction. Can cause some bottom tension variance. The needle hole size may be a bit large but that much variation I'd think a real tension issue, not just needle size. Saw you had two thread weights, but that isn't likely a contributor. Don't know your machine type but it would help to know that. Pull a good distance of thread slowly from the bottom bobbin, should remain consistent to the feel. Any hitches there, check, could be some dirt under the tension spring or debris in the bobbin area. Rarely too much thread tail from the winding can create some tension anomalies as it spins in the case. All worth a check regardless. If that reveals nothing, pull the thread out of the needle only and give that a top thread slow long pull with the pressure foot down. Sometimes you can lighten tension to more easily check for consistency on that upper thread pull. If you feel any changes in pull on the top thread, check from the needle back to the spool, path, tension engagement (thread partially seated in the discs or dirt in the upper tension assembly) and how the thread is coming off the spool. De-spooling catches or hitches alone will do what you have there but are not usually the culprit unless the thread is old or the tower isn't directly over the cone. Do that pull check at a couple of take-up lever heights if all is good on the initial test, very rarely an older take-up lever wear point grabs more in one position than another, rather unlikely but possible. If all that checks out it's below the needle plate almost certainly.... Then you would check for any burrs in the thread path below the plate and that the latch clearance is adequate. Simply not engaging the latch tang properly into the fixed side of the needle plate will do what you have but generally creates a bigger thread issue on the bottom. Make sure the latch can move freely. Hand crank it over and run some fabric through so you can see what the upper thread is doing, you may just spot the issue that way here. Make sure there is no dirt in the hook area/rotation surfaces and all is lubed. All the above is assuming a vertical axis bobbin but mostly applies regardless. I think you mentioned and I assumed the needle is known good. You can slide test that on some thread. Not always but very often, the above steps find the problem for me. Actually, I can't think of a time they didn't.

Heim joint linkage made me grin. Slick. Planetary