Members NoPleather Posted December 5, 2015 Members Report 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
Members Darren Brosowski Posted December 5, 2015 Members Report 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
Contributing Member Ferg Posted December 5, 2015 Contributing Member Report 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
Members NoPleather Posted December 5, 2015 Author Members Report 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
Members NoPleather Posted December 5, 2015 Author Members Report 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
Members TinkerTailor Posted December 5, 2015 Members Report 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 "If nobody shares what they know, we will eventually all know nothing." "There is no adventure in letting fear and common sense be your guide"
Members NoPleather Posted December 5, 2015 Author Members Report 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
Members Big Sioux Saddlery Posted December 5, 2015 Members Report 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
Members NoPleather Posted December 5, 2015 Author Members Report 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
Members TinkerTailor Posted December 6, 2015 Members Report 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 "If nobody shares what they know, we will eventually all know nothing." "There is no adventure in letting fear and common sense be your guide"
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