NoPleather Report post Posted December 5, 2015 (edited) I have had this problem a few times, but am usually able to correct it, sometimes by myself and other times with Bob's help. This time, neither Bob nor I can figure it out and am losing confidence in the machine. Thread, needle and machine all acquired from Bob. I have adjusted and rethreaded at least a dozen times, lubricated, and cleaned the botton bobin area, checked the bobbin and tension etc. So, the machine has become a major nightmare. Edit: CB4500 Machine. Pic attached of the problem... Edited December 5, 2015 by NoPleather Quote Share this post Link to post Share on other sites
Darren Brosowski Report post Posted December 5, 2015 A/ Breathe......... B/ Assuming we are looking at the top thread on the left then there can only be two problems - 1/ There is a binding issue on top and this can be as simple as the thread not coming off the spool properly. As soon as a stitch goes bad then stop and pull the thread off the spool. Check how it runs through the various guides. You go through the top guide once only. - 2/ Is the bobbin thread well wound? loops can cause problems. There is nothing wrong with the "machine" that can cause these issues. Quote Share this post Link to post Share on other sites
Ferg Report post Posted December 5, 2015 I guess I am a little confused about what your terrible problem is. As Darren said, there is nothing wrong with the machine. Folks with a new machine have a tendency to blame the equipment when it is usually operator error. LOL If the stitching on the left side is what you are referring to: Your tension is way off. Let's start at the beginning. Set your top tension as near to middle as possible, sew a few stitches to see if it is the same. I will assume it will be the same. Adjust the tension on the bobbin with a very small screw driver (you can feel tightness better with a small one), so the screw is just snug. Now, back off the bobbin tension 1/8th turn, check your stitches. Do this until you have the knots in the center of the leather. You should not need to adjust top tension after setting it halfway while doing this, at least until you see if this works. Your needle is making huge holes, do you have the proper size for the thread you are using? What size thread is that? What size needle? We will get you up and running, just be patient and take a DEEP BREATH! ferg Quote Share this post Link to post Share on other sites
NoPleather Report post Posted December 5, 2015 (edited) - 1/ There is a binding issue on top and this can be as simple as the thread not coming off the spool properly. As soon as a stitch goes bad then stop and pull the thread off the spool. Check how it runs through the various guides. You go through the top guide once only. Top guide is run once, and Bob personally walked me through the threading process, along with his video so we're good there. However, I will stitch again and wait for a mis-step and check the tension on the thread throughout. - 2/ Is the bobbin thread well wound? loops can cause problems. I have replaced the bobbin three times, all have been wound quite nicely by the machine and appear to be releasing thread under consistent tension. The same bobbin, wound through the machine for the past year have produced no issues thus far, but things change. There is nothing wrong with the "machine" that can cause these issues. The adjustments are on the "machine", if it is adjustments. None have been really tampered with in over a year since I have had the machine, other than slight tweaks recommended by Bob that have been helpful. Another note; the machine has run through it possibly 100 projects in that time with little to no issues. Obviously that is not a significant as it is a hobby so the machine looks and works like new, until recently. I will follow your advice and report back with pics. Best.. Edited December 5, 2015 by NoPleather Quote Share this post Link to post Share on other sites
NoPleather Report post Posted December 5, 2015 (edited) I guess I am a little confused about what your terrible problem is. As Darren said, there is nothing wrong with the machine. Folks with a new machine have a tendency to blame the equipment when it is usually operator error. LOL Thanks, Ferg,..I am laughing. But the machine is acting-up. It may be the operator that can't repair it at the moment, but it has not been abused and only lightly used--tension or bobbin issues are the plague of leather hobbiest. I have spent hours filming and going back and forth with Bob, but he has other customers and problems to deal with, and I understand that. If the stitching on the left side is what you are referring to: Your tension is way off. Let's start at the beginning. Set your top tension as near to middle as possible, sew a few stitches to see if it is the same. I tried this a few times with no luck--the birds started flying by the machine thinking their new home was under construction. I will assume it will be the same. Adjust the tension on the bobbin with a very small screw driver (you can feel tightness better with a small one), so the screw is just snug. Now, back off the bobbin tension 1/8th turn, check your stitches. Do this until you have the knots in the center of the leather. You should not need to adjust top tension after setting it halfway while doing this, at least until you see if this works. I have see this done, and believe it may very well be the cause of the problems. Let me give this a shot since other tension setting has only resulted in minor improvements. Your needle is making huge holes, do you have the proper size for the thread you are using? I have been using the same needles and thread for the past year with very few minor issues on a variety of leathers. What size thread is that? Bonded Nylon, pre-lubricated thread, 277. What size needle? Schmetz, NM 200, Size 25--all provided by Bob. We will get you up and running, just be patient and take a DEEP BREATH! This is one of three hobbies; the others being a CNC machine and coding knowledge, and a South Bend Heavy 10 Lathe I just restored from the ground up with the addition of a Variable Frequency Drive (VFD). So when one hobby goes down, the others pick up. Thank you for the guidance. I shall report back shortly... ferg Edited December 5, 2015 by NoPleather Quote Share this post Link to post Share on other sites
TinkerTailor Report post Posted December 5, 2015 (edited) You can use a vfd on your cowboy and would be much better than the chinese servo motors most use. You could lock the clutch and use any old 3 phase clutch motor this way am i right? Some of those motors are BEASTS. Those things are free around here. No-one has 3 phase and clutch is a swear word.... The sewing world has not embraced vfd like the machinist world it seems, though in theory it is likely the best way to go for a slow moving leather stitcher. Edited December 5, 2015 by TinkerTailor Quote Share this post Link to post Share on other sites
NoPleather Report post Posted December 5, 2015 (edited) You are correct; a VFD would provide infinite speed adjustments and consitent torque throughout, as opposed to reduced speed/reduced torque. Running two legs of power provides fanastic variance across the spectrum. Applying the latest technology to American steel and a 240 motor gave my lathe incredible flexibility. I received so many emails when I posted it on a machinist forum I had to take it down. I'll put together a video and provide a link. If I can find the link for my last lathe, for VFD evaluation purposes I'll put it on here for grins. Incredible project. Sorry for the hi-jack. I often wondered why no one has adopted such technolog for these machines. I could do it but my machine easily handles my projects as is, so it would be a waste of time and money (for me). You can use a vfd on your cowboy and would be much better than the chinese servo motors most use. You could lock the clutch and use any old 3 phase clutch motor this way am i right? Some of those motors are BEASTS. Those things are free around here. No-one has 3 phase and clutch is a swear word.... The sewing world has not embraced vfd like the machinist world it seems, though in theory it is likely the best way to go for a slow moving leather stitcher. Edited December 5, 2015 by NoPleather Quote Share this post Link to post Share on other sites
Big Sioux Saddlery Report post Posted December 5, 2015 Looks very much to me like what happens when the thread hangs up on the spool, as someone already mentioned above. Some spools never bother, some are a problem from start to finish. They can start hanging up part way through a spool when they have not been a problem previously. Likewise, some thread tends to kink coming off the spool; the longer you go without pulling the thread out of the machine and getting the kinks out, the worse it gets. Some old machines cam with a factory thread rack where the spool sat horizontally and turned as the thread came off it, avoiding the kinking problem. Again, some spools give no problem, others are a problem to the end. Quote Share this post Link to post Share on other sites
NoPleather Report post Posted December 5, 2015 Yeah, you know I found a burr on the spool of thread that was causing some hang-ups. I could not tell how far down the line it was but cut it out anyway. A few minutes later while trying to test the unit after replacing the needle and bobbin, the thread ran out on me. So the end was closer than I thought. Sadly, the problem continues after trying every suggestion noted above. Four hours of working on it has yielded a variety of results that eventually ended me back at where I started. I am having a sewing machine specialist come out to the house next week. He used to work in the factories in China maintaining these machines so I imagine he'll make short work of it. I am convinced the bobbin is the problem. My wife owns a national children's clothing company with sewing facilities in Bangladesh, China and Vietnam, and more recently the US. The quality has become quite poor, and they knock everything off with cheaper materials and thread and sell it for change. They are basically fishing for ideas when they produce your products. Needless to say, the wife looked at it and told me your bobbin isn't working properly. So she's sending her guy out. I'll keep you posted... Quote Share this post Link to post Share on other sites
TinkerTailor Report post Posted December 6, 2015 Are you cutting the tail of the thread off so there is NONE sticking out the hole? It can cause the bobbin to act weird tension wise if it is hanging out. also, is the spring still in your bobbin case? I am assuming you have tried more than one bobbin, because a burr on one can cause it to hang up as well. Is the bobbin tension set screw locked down? When i got my machine, that set screw was missing and my bobbin tension would gradually back off until there was none. It was quite perplexing, however when it happened, i would be stitching along and slowly i would have loops forming on the top just like you. Sometimes it would happen fast. I would then back off top tension, get it almost right and it would come back. I chased this until i had no tension at all, and noticed the screw was not there......Techsew sent it out and i had it within days, and my tensions have been rock solid since. Quote Share this post Link to post Share on other sites
NoPleather Report post Posted December 7, 2015 Well Tinker, I have heard nothing back from Bob, even asked for a local contact with no luck hoping I could get some counsel. I do recall Bob mentioning he had picked-up some bad thread and just maybe I bought it. I can state that when I changed the thread the problem has disappeared. The problem is it's a funky color. I changed it out to see if it would make a difference. Apparently the thread is getting all spindled and tangled too. Using this other thread has at least eliminated the problem. So, if you have any suggestion for a thread supplier, please pass along. I'm still having the Asian Contingency out to the house for grins. There are some pretty nice videos on youboob for an identical machine, but different name that runs through a step-by-step bobbin cleaning, adjustment etc operation that was easy to follow. My machine was spotless, screws appeared to be in order etc. Quote Share this post Link to post Share on other sites
Red Cent Report post Posted December 8, 2015 I seem to have had the same problem some time back. Dirt Clod suggested I go to polyester and use 277/207 on the top/bottom. Solved the problem. I have a Cobra 4 and I can tell you it ain't threaded as suggested from the factory. The CB4500 is the same machine as the Cobra 4. My C4 does not have the post on top to wind the thread. Steve said they decided they didn't need it. I have said it before; there are 937 ways to thread these machines correctly. The statement that the path of the thread should be inspected is a wise one. Wiz preaches that one. I had a spindle of thread that would catch as it unwound. It would cause a skipped stitch. I could not detect the hang up when it happened. I could see the skipped stitch as it occurred. One time I happened to see the string jerk out of the corner of my eye. Repositioned the spindle and guess what-it worked. Steve and Bob know a whole bunch. But they have learned by experience also. Stuff happens. Good luck. Quote Share this post Link to post Share on other sites
NoPleather Report post Posted December 8, 2015 Yes, that is the other machine. I have counted no less than 5 ways to thread, and I chuckle until my machine goes wonky on me. Interesting idea; 277/207. Hell, I'll try anything a this point. My white thread is fraying and spindling and even busted a needle off by throwing off the rithym of the needle speering the tip off into my thumb. I pulled it out with little fan-fare other than a burning pain. Never forget how dangerous these machines can be and wear eye protection--I always do. Any suggestions as to where I can get some good thread? Quote Share this post Link to post Share on other sites
NoPleather Report post Posted December 9, 2015 Sewing machine repair guy stopped by on his way to a client's house, and took a quick look at my machine and immediately stated the thread was of very poor quality; inconsistent and fraying (white), the black was far too stiff but should sew better than the white. He suggested throwing them both away and getting better thread before trying to make any adjustments to the machine. He plans to drop by on Friday to work the mechanics out with better thread. Any attempt at making any lasting adjustments with poor thread is a waste of time, in his opinion. Interestingly, the white thread looks better (when it works) than the black thread. But I've had problems with both. I'll update all on Friday or Saturday before rendering a final diagnosis. Quote Share this post Link to post Share on other sites
YinTx Report post Posted December 10, 2015 One of my machines appears to be doing a very similar thing, and I'd been beating my head against a brick wall trying to iron it out before I finally gave up many months back. So, I have been following this conversation diligently hoping that I could get a nugget to solve the issue. Please keep us up to date with the details and your solution, I really appreciate you putting the effort into sharing with us. YinTx Quote Share this post Link to post Share on other sites
silverbullet Report post Posted December 10, 2015 It almost to me looks like the thread is thinner where it's pulling thru, which it could be a tension issue , ck the lubrication in the machine too. If something's not moving smooth it could cause problems. Just my thoughts Quote Share this post Link to post Share on other sites
NoPleather Report post Posted December 17, 2015 Update: The Asian group ended up going to Vietnam for the week so I missed them. However, Bob gave me the name of a local gentleman, Alexander, in the Dallas/Fort Worth area that took a look at the machine for me and spent a good amount of time working on it, and changing the routing of the thread and sanding the foot where the thread goes through. But in the end, he suggested I throw the thread away and left me a new spool. My thread had fuzzy areas on ocassion and you can't stop during a project and solve it. Needless to say, I am extremely grateful to Bob and Alexander. These machines might be made of steel and weigh a ton, but they are VERY sensitive. The threading of the machine is completely different than anything I have seen, and the thread is a very nice smooth consistency. While Alexader stitched just about every thickness you can imagine, I have not had time to put the machine through its paces yet. But Alexander's work was top-notch. In fact, that guy is a scientist when it comes to these machines. Shout out to Alexander in Dallas. Hell of a guy. Thank you. I'll post back shortly with comments and pictures. Quote Share this post Link to post Share on other sites
l2bravo Report post Posted December 25, 2015 Nopleather, yes you can mix smaller thread sizes on the bobbin. The other day I got a bunch of new thread in. Stupid me, I ordered 346, but forgot 277 in the same color, but did get 205. I run a Cowboy 3200. So I ran 205/346, on a 15-18 oz. oil tanned bag. It laid beautifully, and knots were perfect. Glad to hear you narrowed your problem. Quote Share this post Link to post Share on other sites
Darren Brosowski Report post Posted December 26, 2015 It is amazing how much the thread can influence a machine. Quote Share this post Link to post Share on other sites
J Hayes Report post Posted December 28, 2015 I had problems with the thread dropping off the spool and snagging on the base of the holder, read somewhere here to put a ladies nylon stocking on the spool to solve it Quote Share this post Link to post Share on other sites
wlg190861 Report post Posted December 28, 2015 (edited) I bought a cb4500 a few years ago a had that problem myself at the beginning. First, make sure your top thread is threaded right and not catching on anything. What I did and works for me is I tightened my bobbin almost All the way tight an the rest of my adjusting is done on top. I can sew from 2 oz to 20oz with no problem, any adjustments needed are done on top. Edited December 28, 2015 by wlg190861 Quote Share this post Link to post Share on other sites
l2bravo Report post Posted December 30, 2015 Nopleather, I ordered my machine from Ryan. Alexander happened to have one ready to roll, so it shipped from him. I've had a couple of questions, and ordered a few things. You are absolutely correct, in that Alexander is a really really nice guy, and is crazy smart at these machines. Quote Share this post Link to post Share on other sites
NoPleather Report post Posted January 1, 2016 I have been busy with other projects, given the Christmas break provides opportunity for me to get a lot done. I did sew on it earlier this afternoon and oil ran all over the leather, but no matter--it was a sample piece. It is laying down very well and I plan to sew some books tomorrow. It could have been a combination of things, bad thread, a possible bur on the foot that would catch the fuzz on the thread, poor adjustments and in need of a more thorough oiling. I don't know which one or all. I do know that he completely re-routed my thread and it seems to run smoother. The more places you run it through, the more opportunity there is for problems. Quote Share this post Link to post Share on other sites
YinTx Report post Posted January 1, 2016 Would you mind showing us the new path that the machine has been threaded with? Thanks in advance, YinTx Quote Share this post Link to post Share on other sites
JLSleather Report post Posted January 1, 2016 I have a Cobra 4 and I can tell you it ain't threaded as suggested from the factory. Where would a guy find this "factory" instruction? Quote Share this post Link to post Share on other sites
