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Gymnast

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About Gymnast

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  • Gender
    Male
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    Denmark
  • Interests
    Applications for gymnastics. Repair of tarpaulin covers and with webbing. Rubber rope and terminations.

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    Sewing machines and ways to use them
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  1. More things can cause skipped stitches. I remember a video by Uwe, on a Juki 441 class machine that can have a problem with skipped stitches in reverse. Perhaps it can help:
  2. I think it needs to be the manufacturer of the machine, that make the S-twist requirement. I just noticed, that many normal machines using normal Z-twist thread got different direction of the hook relative to the needle. In the previously shown video, you got the hook approaching from right from needle perspective. I have looked at some of my machines and some other videos, and the direction of the hook vary: Hook approach from right: Singer 66, Singer 201, Pfaff 130, Pfaff 138, Singer 501a, Consew 206rb, Pfaff 545 Hook approach from left: CB4500, Machines with CB-hook, Machines with long shuttle, Husqvarna Viking 6010 (and similar with double rotating vertical hook). So it seems that this decision for the designer of the sewing machines was not influenced by the preferred use of Z-twisted thread. I have tried to press a needle with thread through some vinyl and retract it a bit to simulate the loop forming. I think there is a tendency, that the thread gets locally twisted near the needle due to the friction against fabric, and therefore I see a tendency that the thread loop goes a bit to the right as seen in this picture, but you also have a significant variation on that every time you try: When you look this photo, you may prefer to have the hook from right. But I tend to believe, that this matter has little significance.
  3. The Pfaff 545 should be able to handle a Tex 70 thread all right. But I would not risk to buy an unbranded thread from Amazon. Do you know if it is nylon or polyester, bonded or not bonded? Normally a size 16/100 or 18/110 needle size would be used for a Tex 70 thread. A 21/130 needle is too thick. You think you got some problem with the needle thread tension. At lowest tension setting, I think you should be able to set a thread tension below 1.5 Newton just before the take-up lever. At some place of the thread guides you may have some metal damage that creates unregular tension. Try to thread the machine one step at the time and at each step try to feel the thread tension by hand when you pull the thread. It should feel smooth with little variation. Also the thread stand can be the problem - how do it look like? One common beginner mistake can be to have a heavy thread spool turn around a vertical pin, or the thread drops down under the spool. You got both bobbin thread tension and needle thread tension to worry about. While you are not experienced in sewing, it can be nice to be able to measure thread tension (it still is for me). This is a video about measurement of thread tension: https://youtu.be/kINRgj42GnI
  4. I got a Singer 66, Singer 201 and a Pfaff 30, and they are all quite capable and durable household machines. But they are not that durable as industrial machines. The main problem will be the feed of the leather. The feed dogs may leave permanent marks on the leather surface. When you sew more layers it can be difficult to have an even feed at top layer compared to lower layer. You can do helpful modifications like speed reducer, a heavier tension spring and a food with a slid to the back. I normally prefer to use the Singer 201 and Pfaff 30, because they got full reverse stitch length. You need to turn your work to lock the stitch with the Singer 66. I think the the Singer 66 got lower thread friction at the hook than other machines, so in this way it operates with less driving power. You may find some tips on my channel below. This is a video of a Singer 66 sewing Tex 135 thread in 6 layers of vinyl: https://youtu.be/p6tsFd8kpbM
  5. Can you inform us what exact type of thread, that you use? It needs to be for a sewing machine and of a reasonable thickness.
  6. I agree, that the normal timing adjustments of needle bar height and timing of hook is important. I just think these adjustments are well defined, because the same needle system got the same distance between needle but and upper edge of the needle eye when needle size is changed. I have had a harder time finding information about needles systems and the dept of the scarf and some of the geometry here, when you change needle size. So this is why I decided to discuss this in forum. I do not have a CB 3200 or 4500, but I have seen videos of them. They have got an oscillating hook and Uwe have made a nice video about it: According to Uwe, the play of the shuttle hook regarding distance to needle needs to be low and I guess it means below 0.1 mm. The distance is adjusted by having more rings (race back) to be replaced behind the shuttle, and the rings got different thicknesses. Uwe comments about the orientation of the race back, that can influence reverse stitching. Nmgunguy, did you adjust the distance by replacing the ring or did you do it in some other way? I got a Bernina household sewing machine with a oscillating CB-shuttle hook. It have got a quite high play of about 0.3 mm regarding distance to the needle. For this machine I see the lowest distance when the needle go down and pass the hook while doing so. The lowest distance is determined by the part of the needle outside the scarf and near the needle eye. Perhaps you will se the same with this much larger machine, because it is also an oscillating hook machine.
  7. After studying the subject a little more, I have also become more relaxed in relation to this subject. Sometimes I have seen strong warnings in some sewing machine forums, but I have never personally experienced major problems with this. But it has sometimes been difficult to completely decipher instructions on adjustment, where e.g. is already quite some slack for a CB shuttle hook - typically 0.3 mm. It is also my experience that these "CB shuttle hooks" with a little slack in outer positions might be able to hit the needle, but that it usually does not cause problems. When sewing Jersey, I have experienced lost stitches, and after an adjustment, it has solved the problem. And it has so often been the case that the machine had been incorrectly adjusted. Here I have not always been aware of the extent to which it could mean something for other needle sizes. Now I know a little bit about that. I have not usually seen the big differences with a change of 0.1 mm. However, an incorrect adjustment to about 0.4 mm too much distance will be apparent when sewing jersey. Due to the normal geometry of double-rotating "hook", those machines can probably be adjustable to a slightly closer distance.
  8. Nmgunguy, So based on your experience and the Renters Book, it may look like the sketch below, when you change needle size on a sewing machine using round shank needles, that is used on industrial sewing machines: If you adjust hook needle distance here to a smaller needle and change to a larger needle, you might encounter problems. It will also depend on the moving geometry. You got a risk, that the needle at eye below the scarf may hit the hook, when needle moves upwards. It depends on the hook geometry and how fast it go past the needle.
  9. I think we all are in for some education here I have tried to look in a German book by Wilhelm Renters from 1957, and I took a copy of one side below. It seems to me, that you are right. There is a lot of needle systems, so I guess we cannot be sure. But Renters explains, that the flat shank needles (typically for household machines) are as I described in my drawing above. But the round shank needles got the center with the point of the needle in center of the shank. Nmgunguy, if you state what needle system your machine use, I guess somebody can answer your question.
  10. Juki DNU-1541S have got a rotating hook. When you adjust the clearance that close, is it then to the bottom of the scarf of the needle? I just think that the hook needs to have a geometry, so the needle do not hit the hook further back, when it moves up. I got four domestic machines 66k and 201k. For both of them, you cannot adjust the needle hook distance without making very serious modifications. It means that they most likely have got the factory setting of distance. When these machines was designed, they were most likely designed for the 705 needle system without any scarf. I do not think, that you can get this needle system any more, and they were mostly replaced by 130/705H, that is used today, and these needles all got a scarf. I measured the distance to the bottom of the scarf of a Schmetz 130/705H, 18/110 universal needle. The dept of the scarf is 0.25 mm. Singer 66k von 1910 - 0.45 mm Singer 66k von 1930 - 0.4 mm Singer 201k von 1950 - 0.5 mm Singer 201k von 1954 - 0.5 mm So the needle hook distance outside the scarf or to the old system would be 0.15 mm to 0.25 mm. So I do not think these machine will ever hit a needle. I have measured the scarf dept of a 10/70 needle to be 0.1 mm and a 22/140 needle to be 0.4 mm. But you do have other kinds household machines, that got the possibility to adjust the needle-hook distance, and then of cause you can get into problems.
  11. This is what I think happen to the hook needle distance when you change needle size: This sketch is only based a few measurements on some household sewing machine needles. I also got some input from a guy knowing a bit about the needle systems before it was common to make them with a scarf. I have not been able to find more detailed information about how a definition of a needle system might define this. So I hope someone here may know more about this. If you adjust the needle hook distance to a minimum with a large needle and make use of the needle scarf, and you later on change needle size in the machine to a small needle, that you might have the hook hitting the needle. I guess you need a rotating hook in order to get the hook close to the bottom of the scarf, because you need the point part of the hook to be at some distance when the scarf have moved upwards.
  12. This is from a manual of a Household Janome HD9 straight stitch sewing machine. I think it is a relative new type of sewing machine - perhaps 10 years old, but is still being sold. The only specifications I can find regarding how heavy thread or fabrics it may be able to handle is this table on page 32. Do you know what kind of threads these are?
  13. Is it always the case? I guess this would be the case, if the hooks are spinning in opposite directions for drop in bobbin machines. If you look this part of video, you see that the hooks spin in same direction, and therefore the hooks pass the two needles in the same geometrically way. Therefore I should think it would require the same kind of thread for both needles and bobbins.
  14. I normally call the thread S-twisted and Z-twisted. Almost all thread is Z-twisted unless otherwise specified and can as default be used on all sewing machines except for the situation Wizcrafts points out. We had a thread about 2½ years ago about twisting of thread:
  15. Hello Jonas Amann Serafil thread got good quality, and I have used it a lot, and it is easy to buy in Denmark. It is a polyester thread. On the Amann website you can find the recommended needle sizes for it. Nylon thread is a bit thicker and almost the same thickness as the polyester thread for the same weight, because the density of polyester is a bit higher than nylon. https://www.amann.com/products/product/serafil/ I think the link proposed by kgg to Toledo provides a good table to you as to the thread size specifications most used on this website. But there is more systems to define thread sizes than that, and some of them can be quite difficult to figure out. /Viggo
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