Thread tension and twisting

[Gymnast]

I know that twisting of thread is often debated in this forum. I have tried to make a video of some of my findings in that regard.

I look forward to your remarks

[kgg]

Good video I enjoyed it. I suspect that the short thread run across the top of the machine to the tensioner doesn't help with the twisting. What I found using 8 oz spools of bonded black nylon and with the spool in the typical vertical position the thread had enough spring back on some spools to actually coil around the bottom of the spool and jam. This I figure has a lot to due with the matter in which the thread is spun on the spool at the factory and black seems stiffer probably do to the dying process. I don't have this problem with the larger 1lb spools of bonded polyester.

My solution was to mount any spools that are of the 8 oz size horizontally and let the thread come off from the more natural position with no noticeable spring back. The only thing I had to do was make some minor adjustment to the top thread tensioner to compensate for the slight increase in resistance of the weight of the spool and gravity. I have mostly converted from bonded nylon to bonded polyester thread for this reason and some other factors as well as only occasionally using 8oz spools.  The topic " Bonded Nylon thread 8 oz uncoiling solution " will show some pictures of my first go at a easy cheap solution which I have since completely redone, modified, added rollers for mounting two 8 oz spools horizontally and incorporated a platform to accommodate three 1lb spools.

kgg

 

[Gymnast]

19 minutes ago, kgg said:

Good video I enjoyed it. I suspect that the short thread run across the top of the machine to the tensioner doesn't help with the twisting. What I found using 8 oz spools of bonded black nylon and with the spool in the typical vertical position the thread had enough spring back on some spools to actually coil around the bottom of the spool and jam. This I figure has a lot to due with the matter in which the thread is spun on the spool at the factory and black seems stiffer probably do to the dying process. I don't have this problem with the larger 1lb spools of bonded polyester.

My solution was to mount any spools that are of the 8 oz size horizontally and let the thread come off from the more natural position with no noticeable spring back. The only thing I had to do was make some minor adjustment to the top thread tensioner to compensate for the slight increase in resistance of the weight of the spool and gravity. I have mostly converted from bonded nylon to bonded polyester thread for this reason and some other factors as well as only occasionally using 8oz spools.  The topic " Bonded Nylon thread 8 oz uncoiling solution " will show some pictures of my first go at a easy cheap solution which I have since completely redone, modified, added rollers for mounting two 8 oz spools horizontally and incorporated a platform to accommodate three 1lb spools.

kgg

 

Thanks for the reply.

I have not tried the 8 oz spools of bonded Black nylon. The thickness of the thread is of cause also a factor in this. When the thread is Loose near the spool, kinks can easely form there. But the important results presented in the video is, that you in the first part of the threads going away from the spool actively can create twisting in both directions. So you should be able to avoid kinks near the spool, but perhaps you then get problems further on the threads way.

[dikman]

Gymnast, you certainly have an inquiring mind! Good video.

kgg, I remember your original design because it got me started! Have you posted photos of the final design?

[nylonRigging]

Thanks for taking the time to make that video . It gave me a lot to think about, will watch a couple more times to properly digest .
Use threads #69 to 346, I use primarily 16oz. spools or larger bonded nylon . Always the 69 nylon can get pretty unruly when getting down to the last 1/4" on the cones .
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[Gymnast]

Thanks for your nice replies kgg, dikman and nylonRigging. I hope the video will help you. I should have some of the nylon thread anyway, and then I may taste some of your more severe problems with it.

I think, that all manufacturers of thread try to make the thread come off the end of the spool without internal twisting (moment) forces in the thread. But perhaps these manufacturers can vary on their quality in this regard. And perhaps even worse, that their twisting from spool vary. Anyway you should have the possiblity to actively do something about it in how your thread passes your machine and other things on its way.

[Wizcrafts]

52 minutes ago, Gymnast said:

I think, that all manufacturers of thread try to make the thread come off the end of the spool without internal twisting (moment) forces in the thread. But perhaps these manufacturers can vary on their quality in this regard. And perhaps even worse, that their twisting from spool vary.

It is a known fact that the darker the color, the more twisty bonded thread usually is. Black bonded nylon is the worst because it is often double dyed (first dark blue, then black), then bonded. The thicker the thread, the more like a coil spring it can be.

The same size thread in white and straw color may be soft and feed perfectly straight off the spool.

[Constabulary]

I honestly never faced a serious thread twist problem. Gymnast - I guess you run an (probably oversized?) (bonded nylon?) thread through a vintage domestic machine and you are not using a proper thread stand - rule of thumb on this regard (as far as I recall): The position of the guide hole in the boom of the thread stand should be at approx twice the height of the thread spool (or more) and centered directly above the spool. Furthermore - this machine for sure is not meant to work with thread or thread heavier than approx #69 . I´m sure this machine will run perfect with polyester or cotton thread of a size up to #69 (or less). This machine has no serious thread guides as used on some "real" industrial sewing machines that can handle heavier thread. F.i. the Singer 111 has several thread guides / guide holes for "untwisting" thread - and that's what they are meant for! In some cases it even matters in what angle the thread "enters" the tension unit - it can well be that the thread pops out of the tension disc when the angle is wrong and/or the thread is too lose (no proper thread guide before the thread enters the tension unit). For this reason some manufactures have a thread guide of which you can alter the angle. So - using the right machine also matters - it´s not just the thread that causeuse the problem. Using the right components (incl. the right machine with the right thread for a certain operation... concluding - meaning the whole setup) but as always there is no right or wrong - the truth is somewhere in the middle. However - I´m not using any nylon thread at all. I`m mainly using polyester or poly/cotton core spun thread or - not kidding - very old US made cotton thread (for historical purposes). I´m f.i. sewing harnesses for BC-1000 back pack radio with this cotton thread (like they did in the 1940´s) - I never got a complaint because of broken seams but that's a different field - I know.

I understand that a lot people are using bonded nylon because of its braking strength - but - folks should ask their self if their products really needs this breaking strength. Will there ever be so much "force" on the seams of the finished product that it will break the thread? I honestly think that for most purposes a good quality polyester thread is sufficient and is most likely will solve a lot of "thread feeding" issues and it most likely will never break.

Edited May 10, 2019 by Constabulary

[Gymnast]

Thanks Wiz. Important observations due to color and how the thread manufacturer produce the thread.

I made the "clips test" with two spools. I placed the spool at a platform near the ceiling and liftet the thread up through an eye at let the thread go controlled down to the floor with a clips on the end. For the red Serafill 20 thread (polyester continuous filament tex 135) I counted 6 turns anticlockwise each meter. It is from a 2500 m spool. I did se same for a Serafil 40 Black thread and got the same value. It is from a 1200 m spool. I suppose this could be one way to quantify how much twist you have in the spool.

I did a test more regarding twist due to tension in the tread. I had a 2 m thread hanging Down from ceiling. Then I added 1 clips more on the clips already at the end. Its an extra tension to the thread of 0.0033 N. The Serafill 20 responded with 0.7 turn anticlockwise. The Serafill 40 responded with 1.5 turn anticlockwise. It is small values, so I do not think you need to take this into account as long as you apply such low weights.

 

[Gymnast]

Thanks for your response, Constabulary.

I am aware, that I use my sewing machines to jobs, they were not designed for. The machines may be destoyed by it. And it causes some problems for me. I describe the problems and how I try solve them, and perhaps somebody can use this information. I think that is what a forum is about. For some it will make sense for others not. I think problems with thread twisting is a popular subject in this forum. When you have got the good machine for the job, it may solve most of the problems for you without too much knowledge from the user. However I think, that a leatherworker sometimes will do a job on the limit for what his sewing machine can handle.