Members Michiel Posted Sunday at 04:24 PM Members Report Posted Sunday at 04:24 PM 21 hours ago, toxo said: This makes no sense to me! Are you suggesting that the whole bobbin has to move somehow? Yes, that's right. You can't make stitches without passing the bobbin through a loop in the upper thread. That's why you need a bobbin. It's quite difficult to understand, which is why this discussion keeps coming up on this forum from time to time.
Members Michiel Posted Sunday at 04:29 PM Members Report Posted Sunday at 04:29 PM The best thing is to try it yourself (as I described), then it will become clear what happens at the bottom of the fabric to make a stitch.
AlZilla Posted Sunday at 04:33 PM Author Report Posted Sunday at 04:33 PM In 1835, a guy named Walter Hunt moved the eye of a sewing needle to the pointy end for the sewing machine he was working on. The very next day, he caught a load of grief about the stupid BOBBIN from some guy on Reddit. It still rages today ... “Those who can make you believe absurdities can make you commit atrocities.” - Voltaire “Republics decline into democracies and democracies degenerate into despotisms.” - Aristotle
Moderator Wizcrafts Posted Sunday at 11:19 PM Moderator Report Posted Sunday at 11:19 PM 22 hours ago, toxo said: Let's get back to basics. The bobbin THREAD, not the bobbin itself comes from the bobbin, goes through the tension mechanism in the bobbin case and is picked up by the hook along with the top thread right? Wrong! When the needle, which contains just the top thread, reaches BDC, then begins to ascend, it forms a loop on the side where the hook resides. At a certain position of motion, the hook picks up the top thread, above the eye of the needle, and carries it around the bobbin case. The bobbin thread is surrounded and captured by the top thread on its way out and back up. That loop of top thread surrounds the bobbin case as the hook rotates or oscillates back and forth. As the top thread is pulled around the shuttle by its hook, at about the halfway point, the take-up lever pulls the top thread the rest of the way around the shuttle, then up into the material, forming stitches with overlocked knots of the top and bottom threads. The hook is merely a sharp point connected to the shuttle. Some shuttles are rotary and others oscillate back and forth. The top thread that was pulled off of the needle totally surrounds the shuttle on its way back out. The lockstitch process requires that the bottom thread be in a self-contained structure, not fed from an external spool. The top thread surrounding the shuttle would get snagged by an externally fed bottom thread that wasn't contained inside the shuttle. Maybe, someday, somebody will figure out a way to form lock stitches from two spools of thread, one on the top and one on the bottom, without the use of a self-contained bobbin in a shuttle. If that person obtains a patent and produces a working machine, they could become a dad gum gozillionair! Posted IMHO, by Wiz My current crop of sewing machines: Cowboy CB4500, Singer 107w3, Singer 139w109, Singer 168G101, Singer 29k71, Singer 31-15, Singer 111w103, Singer 211G156, Adler 30-7 on power stand, Techsew 2700, Fortuna power skiver and a Pfaff 4 thread 2 needle serger.
toxo Posted yesterday at 12:09 AM Report Posted yesterday at 12:09 AM 40 minutes ago, Wizcrafts said: Wrong! When the needle reaches BDC, then begins to ascend, it forms a loop on the side where the hook resides. At a certain position of rotation, the hook picks up the top thread, above the eye of the needle, and carries it around the bobbin case. The bobbin thread is surrounded and captured by the top thread on its way out and back up. That loop of top thread surrounds the bobbin case as the hook rotates or oscillates back and forth. As the top thread is pulled around the shuttle by its hook, at about the halfway point, the take-up lever pulls the top thread the rest of the way around the shuttle, then up into the material, forming stitches with overlocked knots of the top and bottom threads. The hook is merely a sharp point connected to the shuttle. Some shuttles are rotary and others oscillate back and forth. The top thread that was pulled off of the needle totally surrounds the shuttle on its way back out. The lockstitch process requires that the bottom thread be in a self-contained structure, not fed from an external spool. The top thread surrounding the shuttle would get snagged by an externally fed bottom thread that wasn't contained inside the shuttle. Maybe, someday, somebody will figure out a way to form lock stitches from two spools of thread, one on the top and one on the bottom, without the use of a self-contained bobbin in a shuttle. If that person obtains a patent and produces a working machine, they could become a dad gum gozillionair! I never professed to be a sewing machine expert. What I said was IF you could get a tube coming from below into the the bobbin space through the center of the revolving hook mechanism without interfering with the hook mechanism it could work. The cone thread would simply relave the bobbin thread. Everything else doesn't change one little bit. I was talking about a normal horizontal bobbin. At no time was I talking about any other mechanism and certainly not moving shuttles. Are you saying that IN PRINCIPLE it couldn't work Wiz?
Moderator Wizcrafts Posted yesterday at 12:27 AM Moderator Report Posted yesterday at 12:27 AM 4 minutes ago, toxo said: I never professed to be a sewing machine expert. What I said was IF you could get a tube coming from below into the the bobbin space through the center of the revolving hook mechanism without interfering with the hook mechanism it could work. The cone thread would simply relave the bobbin thread. Everything else doesn't change one little bit. I was talking about a normal horizontal bobbin. At no time was I talking about any other mechanism and certainly not moving shuttles. Are you saying that IN PRINCIPLE it couldn't work Wiz? Yes, that's what I'm saying. I wish it wasn't so. If anybody was able to figure out a way to replace bobbins in a lockstitch machine with a spool of thread, they would have by now. The only workable solution to using bobbins is a chainstitch system. Redwing boot uppers are sewn on triple needle chainstitch machines that were designed in the late 1800s and early 1900s. The company that made these obsolete machines was named Puritan. They only use thread that is on top; one spool per needle. The chain is formed under the throat plate by a so-called "looper" mechanism. The top stitches are almost always perfect. The bottom stitches have loops showing where they are wrapped around the thread that got pulled under the work. Posted IMHO, by Wiz My current crop of sewing machines: Cowboy CB4500, Singer 107w3, Singer 139w109, Singer 168G101, Singer 29k71, Singer 31-15, Singer 111w103, Singer 211G156, Adler 30-7 on power stand, Techsew 2700, Fortuna power skiver and a Pfaff 4 thread 2 needle serger.
toxo Posted yesterday at 12:39 AM Report Posted yesterday at 12:39 AM 4 minutes ago, Wizcrafts said: Yes, that's what I'm saying. I wish it wasn't so. If anybody was able to figure out a way to replace bobbins in a lockstitch machine with a spool of thread, they would have by now. The only workable solution to using bobbins is a chainstitch system. Redwing boot uppers are sewn on triple needle chainstitch machines that were designed in the late 1800s and early 1900s. The company that made these obsolete machines was named Puritan. They only use thread that is on top; one spool per needle. The chain is formed under the throat plate by a so-called "looper" mechanism. The top stitches are almost always perfect. The bottom stitches have loops showing where they are wrapped around the thread that got pulled under the work. But NOTHING would change! I'm not talking about changing anything. Imagine no bobbin, just a tube coming up about a half inch from the inside bed of the hook or the bottom of where the bobbin used to sit. now imagine a thread coming out of that tube and going through the same slit and tension spring in the bobbin case as it does now. If you can't see that you have to tell me why because nothing changes.
Moderator Wizcrafts Posted yesterday at 12:54 AM Moderator Report Posted yesterday at 12:54 AM 4 minutes ago, toxo said: But NOTHING would change! I'm not talking about changing anything. Imagine no bobbin, just a tube coming up about a half inch from the inside bed of the hook or the bottom of where the bobbin used to sit. now imagine a thread coming out of that tube and going through the same slit and tension spring in the bobbin case as it does now. If you can't see that you have to tell me why because nothing changes. You're missing the main point of how the bobbin functions in a lockstitch machine. In order to overlock two threads to sew things together firmly, you need to cause the top thread to wrap around the source of the bottom thread. It surrounds the bobbin case/shuttle completely. This precludes having the bottom thread coming from anywhere except from a self-contained bobbin that resides inside the shuttle case. Any external thread would jam the machine as the loop goes around the shuttle. If that thread was feeding through a hole on the middle of the shuttle, the top thread would get snagged by it as it tried to work around the top and bottom of the shuttle. You see, the normal position where the bobbin/bottom thread gets pulled up is after the tension spring and under the throat plate. The top thread, having surrounded the shuttle, with its bobbin, pulls up with the captured bobbin thread in the middle of its shrinking loop. If you can get a hold of a home sewing machine you can watch how it functions to form stitches. Then you'll understand why your system fails to pass muster. Posted IMHO, by Wiz My current crop of sewing machines: Cowboy CB4500, Singer 107w3, Singer 139w109, Singer 168G101, Singer 29k71, Singer 31-15, Singer 111w103, Singer 211G156, Adler 30-7 on power stand, Techsew 2700, Fortuna power skiver and a Pfaff 4 thread 2 needle serger.
toxo Posted yesterday at 01:07 AM Report Posted yesterday at 01:07 AM 9 minutes ago, Wizcrafts said: You're missing the main point of how the bobbin functions in a lockstitch machine. In order to overlock two threads to sew things together firmly, you need to cause the top thread to wrap around the source of the bottom thread. It surrounds the bobbin case/shuttle completely. This precludes having the bottom thread coming from anywhere except from a self-contained bobbin that resides inside the shuttle case. Any external thread would jam the machine as the loop goes around the shuttle. If that thread was feeding through a hole on the middle of the shuttle, the top thread would get snagged by it as it tried to work around the top and bottom of the shuttle. You see, the normal position where the bobbin/bottom thread gets pulled up is after the tension spring and under the throat plate. The top thread, having surrounded the shuttle, with its bobbin, pulls up with the captured bobbin thread in the middle of its shrinking loop. If you can get a hold of a home sewing machine you can watch how it functions to form stitches. Then you'll understand why your system fails to pass muster. Now you're just trying to blind me with science. All I know is my machine works perfectly well with one thread coming from the bobbin. All I'm saying is take the bobbin away. That's all. The bobbin case doesn't move.
Moderator Wizcrafts Posted yesterday at 01:08 AM Moderator Report Posted yesterday at 01:08 AM This topic, although interesting from a technical and argumentative position, has been thoroughly discussed to no end. The facts are what they are and arguing about them doesn't change them. Bobbins are required in lockstitch machines; period. If anybody has a better idea that will keep a bottom thread in play without a self-contained bobbin inside a shuttle, they should patent that technology and try to market it to the major companies that build sewing machines. We will be happy to promote your invention! Thus, as much as this has been interesting, it is pointless. I am locking the topic. Posted IMHO, by Wiz My current crop of sewing machines: Cowboy CB4500, Singer 107w3, Singer 139w109, Singer 168G101, Singer 29k71, Singer 31-15, Singer 111w103, Singer 211G156, Adler 30-7 on power stand, Techsew 2700, Fortuna power skiver and a Pfaff 4 thread 2 needle serger.
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