Why do we still use bobbins?

[AlZilla]

In case anyone is curious, here's the patent.

 

US1009749.pdf

[Cumberland Highpower]

I'm sure you could design a stitcher to simply accept a 1lb spool as a bobbin.  Therefore, no bobbin required! lol

The challenge would be speed of operation though. With so much thread moving through space and time, looping around the massive shuttle, you probably would have a pretty low SPM, defeating the whole idea. Would require lubed thread for sure, but could be done.  I hate winding bobbins.......

There's a bit of a trend that's phasing out sewing as an operation in manufacturing, outside of clothing.  Molded parts, ultrasonic welding, adhesives, etc.  Your 2024 Chrysler might have a good deal of stitching in the interior, but I'm guessing your 2054 Geely SUV won't?

Probably not enough future demand for new sewing technology I think?

Just some thoughts.

 

 

Edited December 18, 2024 by Cumberland Highpower

[Wizcrafts]

The main advantage of a lockstitch sewing machine is the stitches resemble each other on the top and bottom. As leather sewers, we are accustomed to a different result on the bottom and sometimes fight to hide the lockstitch knots from both sides. This stitch is very strong and can hold together somewhat if some of the stitches get cut, or simply break under stress. Off course. a lockstitch machines stops forming stitches the moment it runs out of bobbin thread.

The answer to this is the chainstitch machine. It only has a top thread. There is a looper mechanism on the bottom, under the needle plate, which forms a loop around the thread on the bottom. The top will almost always look perfect, unless the tension is way too tight. The stitches are as strong as the thread rating. But, if one stitch breaks, the entire chain could unravel.

In the days of yore, hard shell rifle cases, some boots and luggage were sewn on chainstitch machines. The loops were hidden behind material glued to the inside of the cases, or the insole on the boot. In many instances, the machine had a top mounted wax pot containing heated beeswax that the thread ran through. The hot wax hardened after a minute or so and those stitches could last a century. From the late 1800s through the mid-1900s, Puritan was the premier brand of needle and awl chainstitch machines. Some are still in use in the RedWing factory, making work boots using two or three needle chainstitch machines. But, now they usually run dry, bonded polyester thread.

[suzelle]

On 11/25/2024 at 2:19 PM, AlZilla said:

In case anyone is curious, here's the patent.

 

US1009749.pdf 558.58 kB · 9 downloads

AlZilla, Yes, that is the patent! Also, the machine you referenced is the one I've seen. There were two different brand names that made the two spool machine. Sorry, it's been a while since I have visited here as I have been so busy. I've had lots of sewing work to do. Glad to see you have been thinking about this. As mentioned, I'd sure buy one of these machines if somebody could figure out how to make an Industrial version!! I almost bought a domestic one about two years ago. It was a Craigslist find and the selling price was only $200.00 in top notch condition. When I've found these machines in past, the canister (lower thread spool can) was missing. But this one had the canister. Long story short, I investigated but didn't buy it due to shortage of space in my shop.

[toxo]

I've only just seen this thread and forgive my simple and sometimes logical mind but why can't the bobbin thread come from underneath, through the same hole in a static bobbin (eventually no bobbin at all)? Everything else would work as normal. I think I must be missing loads.

[AlZilla]

1 hour ago, toxo said:

I've only just seen this thread and forgive my simple and sometimes logical mind but why can't the bobbin thread come from underneath, through the same hole in a static bobbin (eventually no bobbin at all)? Everything else would work as normal. I think I must be missing loads.

Yeah, my mind went there, too. It was pointed out to me that the needle thread has to pass around the entire bobbin in order to capture the bobbin thread. I can't remember if it was this thread or another that someone pointed out the similarity between this design and the large bobbin of the 441 class machines.

The bigger the bobbin that the needle thread has to loop around, the more times it has to go through the sewn material and be pulled back up by the tension arm.

There are some practical limits.  But, how nice would it be to use a full spool in the bobbin???

Here's a link to the earlier post about the old National domestc machine that used a whole spool for a bobbin:

https://leatherworker.net/forum/topic/121438-why-do-we-still-use-bobbins/page/2/#findComment-758063

[AlZilla]

7 hours ago, suzelle said:

AlZilla, Yes, that is the patent! Also, the machine you referenced is the one I've seen.

Oh yeah, I've had a BOLO out on one of those old Nationals since I found out they existed ...

[toxo]

1 hour ago, AlZilla said:

Yeah, my mind went there, too. It was pointed out to me that the needle thread has to pass around the entire bobbin in order to capture the bobbin thread. I can't remember if it was this thread or another that someone pointed out the similarity between this design and the large bobbin of the 441 class machines.

The bigger the bobbin that the needle thread has to loop around, the more times it has to go through the sewn material and be pulled back up by the tension arm.

There are some practical limits.  But, how nice would it be to use a full spool in the bobbin???

Here's a link to the earlier post about the old National domestc machine that used a whole spool for a bobbin:

https://leatherworker.net/forum/topic/121438-why-do-we-still-use-bobbins/page/2/#findComment-758063

 

Don't get it! Leave the bobbin and bobbin case where it is, just static have the thread come out of the same hole of an empty bobbin.