endless bobbin

That appears to be a low-end machine. Have you asked your question of Brother? I know the Endless Bobbin feature for my Singer Quantum XL5000 is an integral part of the machine, not an add-on. It require a special bobbin and threading path using a large cone of bobbin thread.

It does not and you can not add it to a machine.

That link explains to me (at last) how the "endless bobbin" feature works. It doesn't feed the thread continuously into the bobbin area, it automatically refills the bobbin once it's empty.

As such it would need a special design of bobbin, an automatic threader to feed thread to an empty bobbin, a drive to wind the bobbin, a cutter to cut off the thread once the bobbin is full, and another threader to start the new thread. All of this has to get out of the way before sewing can begin, as the fundamental principal of the lockstitch sewing machine is that a loop of the needle thread passes right around the bobbin or shuttle.

I can't see this ever being an add-on feature, and would expect it to be found on top-of-the-range machines only.

I wonder how industrial machines get around the bobbin capacity issue? A winder like this, or maybe an automatic bobbin changer and a supply of pre-loaded bobbins?

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No, typically they use either HUGE bobbins (compared to domestic sewing machine bobbins), or two cones of thread, one of which is fed in under the machine bed through what would be the bobbin area on my machines. :).

That is exactly right. The special bobbin has a small gear on its bottom which turns the bobbin during the re-fill. The supply cone of bobbin thread, having been threaded though a complex series of hooks and pins under the pop-up plate just above and to its left, sits quietly in its location to the right of the bobbin area, and waits for a signal that the bobbin thread has run out. The embroidery process then stops, the machine runs the hoop in a large square until *all remaining* bobbin thread is pulled out of the bobbin, then slowly starts the bobbin spinning until it catches the end of the supply thread in a little hook on the bobbin and winds it tightly around the axel. Once it catches, it re-winds the bobbin *in place*, without having to remove the hoop or take out the bobbin.

Yes, exactly! ;-) The special bobbin does NOT take as much thread as a standard bobbin. It has a tiny gear on the bottom and a cross-section of its inner part is shaped more like a "> I wonder how industrial machines get around the bobbin

I wonder, too. Maybe someone with an industrial will jump in here.

A handful of manufacturers long ago actually made two spool sewing machines, which utilized an actual spool of thread instead of a bobbin. Natinal made them, as did Eldridge. Here's one of them:

-Irene

Cool, thanks! ;-)

There must be a downside: I expect it can't sew very fast, moving a whole reel back and forth and needing to make a big loop of the needle thread to get it over the reel/bobbin. But a great idea if you've got a lot of one colour of seam to do.

I assume they sew more slowly, needing to make a bigger loop of the needle thread and get it round a bigger bobbin

with a continuous feed (like a serger) the machine can only do chainstitch, as far as I can tell.

Interesting readings. Thanks for sharing.

Emily

No, most industrial mchines sew at several thousand stitches per inch as opposed to the low hundreds of most domestic machines. Some of the newer larger embroidery machines (like that amazing Bernina I'll buy when I win the lottery!) have a bigger bobbin and sew at 1100 SPM.

Yes, those ones usually do a chainstitch. It works until a thread pulls loose!

???!!! Really? Doesn't that sort of pile the stitch right on top of each other? ;-> (I know you meant stitches per minute.)

The Singer Quantum XL5000 top speed is "up to 850SPM," but for most embroidery projects I slow it down to about the 3/4 mark. For the metallic thread I used recently, I slowed it down to the slooooowest speed to prevent friction and thread breakage. I now have a bottle of All-Purpose Sewer's Aid (thanks Judie!), but I have yet to test it.

I run my sergers as fast as they will go. ;-) The old Bernette really whizzes, the Huskylock 936 is much slower even at the fastest setting.

I haz the tired, after hand stitching half a wedding gown hem: silk dupion with horsehair braid in it.

My 910 was very fast. The Bernina is too. The Brother is slower, and the only Bernette I ever used didn't get to be too fast before it shimmied off the table into my lap!

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Yeah, my bad, I suspected as much, I should have left it alone, sorry! :-} Have fun with the other half of the hem, AFTER you get some rest.

How strange. I love the little Bernette, it goes like greased lightening and does not vibrate or "walk" at all. I also like that the cutting blade is so much closer to the needle, so I can do curves with much more precision.

The Huskylock 936 on the other hand, is slooow at its fastest setting, and vibrates *a lot*. It would leave the room if it could get away with it. Maybe it needs servicing, although it's only 5 years old, and it has been this way since it was brand new.

Alan, You are correct the industrial machine that have what is being called here endless bobbin are indeed chainstitch machines. Industrial machines sew MUCH faster than home machines even the ones with the large capacity bobbins.

Thanks for the information, Ron, I'm glad to see my guess was right. I did think that anything working on an industrial scale would have to work faster, too.

I would haz the tired too!!! If I'm having a really bad day, DD tells me that I must "haz the dumbs and can't brains no more." lol

Sharon

Just finished that hem, the re-stitching of the bottom of the internal support, and the tops of the 4 godet pleats... About to do the bones and cover some buttons... LOTS of tiddly little buttons!

I haz the sore paws and the numb head. No brains, all dumbs here!