Promblems with getting the thread tension right

[edvin mellergård]

Hey, I recently bought a Janome Easy Jeans 22 and have been making some pack and aother stuff with it. Works great except for when it comes to fabrics with a really thick coating. The problem is that i can't seem to get the thread tension tensioned enough. To start with I have to increase the bobbin tension(not sure if that's the right name in english) to max, otherwise I get big loops on the underside of the fabric. So then I also have to increase the tension of the thread from the spool but even at max I can't get it tensioned enough.

Any ideas? I use Gütermann 50 thread and I've tried jeans needles from 80 to 120 with no difference in the result. The fabric I'm trying to sew is this one http://www.extremtextil.de/catalog/Ripstop-Nylon-TPU-coated-heatweldable-200g-sqm::1636.html

[David Scheidt]

If your getting loops on the back, it's because the top tension isn't high enough. You probably don't need to be fiddling with the bobbin tension, but loosening it is the right way to go here.

Increase the tension of the thread path. I don't know that machine, but it's usually possible to make another loop through the tension disks (the usual machine has the thread entering the disk on the right, going underneath the shaft of the disk, and exiting on the right. Change that so it enters on the right, makes a complete (or more than one) wrap around the disk shaft, and exits on the left.) or the guide pins before the the tension disks.

Also make sure you're threading properly, and getting the thread in the disks.

[Eric Lundquist]

What needles are you using? I found that Schmetz Microtex Needles worked better for "outdoor" fabrics such as ripstop nylon. I've used them successfully with 30D – 70D so far with multiple layers of each.

[Tad Englund]

I think it might not be your tension but the thick coating on the fabric interfering with the thread and needle movement.
You might try and draw a stitch line with some tailors caulk (its more like soap) or something similar and see if that helps.

Roger, needs to weigh in on this one. You might want to search the treads on this, I know it has been discussed before.

[Konrad .]

I agree with David…loops at the bottom can be many different problems, but my first guess would be that your thread tension is too low. Lower your bobbin tension, but raise your thread tension and see what happens. Also, with very thick threads, sometimes the machine simply does not have enough tension to complete a proper stitch…however, I do not believe gutermann 50 is too thick. Good luck!

[Roger Caffin]

First work out the cause. Fairly obviously it is due to the thread not being pulled up as the needle retracts. But why? There are several causes, and several possible solutions. One cause is too much drag on the thread, but another cause is a misbehaving presser foot on the machine. That said, changing the bottom tension is not needed or wise. Leave it alone.

Thread drag cures include:

Very large needle: may or may not work. More of a solution for breaking fine needles on tough fabric.

Polished thread. Many cotton and cotton blend threads have a high surface friction, while pure syhthetic threads slide a lot more easily through the fabric. However, pure polyester threads can be a bit tricky to handle as they can kink. Bonded nylon thread is good stuff for heavy fabrics. A good poly-cotton is a good GP thread.

'Leather' or triangular needle. This actually cuts a larger hole so the thread pulls up easily. Disadvantage: the cut hole. Works fine on leather where the cut hole does not matter too much, but may damage fabric threads.

Lubricate the needle and thread. This may be needed if it is the coating which is dragging. This can happen if you sew very fast, soften the coating and gum up the needle. It also happens everytime you try to sew through wet silicone or PU adhesive! Disadvantage: oil on the sewing. I have yet to try water to cool and lubricate the needle and thread. (Commercial machines sometimes have oilers attached near the needle.)

Talc powder or fine chalk may also help prevent stiction from coatings or very tight fabrics – sometimes. I don't have a lot of hope though.

If the presser foot lifts as the needle retracts you will get loops. The reason is complex. The lifting of the foot is sometimes due to the spring on the presser foot being weak or set too soft to resist the needle drag. That much is obvious.

Why the loops happen is due to the mechanism inside the machine. When you deliberately lift the presser foot you release the tension on the top thread (levers etc are involved) so you can drag the thread and the fabric away. OK, but if the foot lifts through drag on the needle, this upwards movement of the presser foot can also briefly release the tension on the top thread, right when it is most needed. This problem is not all that well known.

If you can adjust the presser foot spring, try tightening it. However, be aware that a high presser foot force can damage light fabrics like silk, silnylon etc.

If you are sewing a short distance or slowly, press down on the presser foot with your finger as the needle lifts. Try not to sew through your finger: the blood marks the fabric and you may break the needle.

If you are sewing for a very short distance (eg applying webbing), turn the machine by hand and rock the needle back and forwards before lifting the needle for each stitch. This may ease the hole and let the needle extract, but it is rather slow.

Cheers

[Sam Farrington]

Another one for the scrapbook. Thanks.

[edvin mellergård]

Thanks for the responses, I'll see if I can loop the thread one more time to increase the tension. btw. perhaps I wasn't really clear but the loops on the underside is on the bobbin thread, that's why I increased the bobbin tension to start with

[Roger Caffin]

On the bobbin thread????
Now that is weird. Photo Please!
Um – a photo of the sewing plus a photo of the bobbin mech with the cover plate removed. I am quite interested.

Cheers

[David Scheidt]

If you can, use two different colored threads. That makes it much easier to tell which thread is which.

Loops of bobbin thread on the bottom can be caused by tension problems, but there's usually something else going on. If the machine stitches properly on normal weight goods (Three layers of paper towel will work, if you don't have something else; I'd suggest getting something like cotton muslin, and getting it sewing properly on that. Then you know the machine is working fine, and get the basic tension right.), I suspect it's skipping stitches, because the loop that the hook grabs isn't formed properly. But a picture will help…

[edvin mellergård]

hi, heres a picture of 4 different seams, all with gutermann 50 thread and a 100 jeans needle.

1 first is with normal bobbin tension and 5 of 9 in thread tension

2 is with normal bobbin tension and 9 in thread tension

3 is hardest bobbin tension and 5 in thread tension

4 is strongest bobbin amd strongest thread tension.

And heres a picture of the bobbin.

I can get it to sew properly in cotton and non coated fabrics. Fabrics with a thin coating is ok but not perfect.

[Bob Gross]

Edvin's machine appears to have a horizontal bobbin.

My machine and every one that I have ever used had vertical bobbins.

Does this make a difference?

–B.G.–

[Roger Caffin]

Hi Edvin

Ah – totally different from what I was expecting. And a bit more complex, but solvable.

The Gutermann 50 thread you are using is a heavy linen thread only suitable for hand sewing. See http://www.craftgate.com.au/products/Gutermann-Linen-Thread%3A-50-meters,-Sold-per-5-reels.html for more information about this. It is NOT suitable for use in a sewing machine, and it will be causing some (if not all) of your problems. You will have to change to a proper machine thread to get good results. I strongly recommend you do NOT use a linen thread (which will degrade) but a poly-cotton thread or, for heavy fabrics, a bonded nylon thread.

If you are in Europe you could chase up the Amann range of threads. I like the Rasant style (poly-cotton) myself. You would need to go to something like a Rasant 20 – 30 to get what you want. Alternatly, try an ONYX thread – that's nylon. All of these are far more industrial than Gutermann.

A secondary part of the problem may be that the machine is not designed for sewing such heavy fabrics with such a tight coated weave and such heavy unsuitable thread. My Elna TSP can only sew up to a certain weight; to make packs I use an OLD black Singer which can handle far heavier fabrics. Such old machines are valuable, because Singer made them to sew everything from silk to hessian sacks. Modern machines are not designed for that. But I do not use hand sewing thread on the Singer; I use a bonded nylon which is actually much stronger. It is the thread which is the biggest problem.

The right hand 3 lines are almost usable, given that the thread is unsuitable. The left hand line shows the bottom thread a bit slack. This is probably due to the thickness of the thread clashing with the bobbin tension system. Don't try to fix this; change to a machine thread.

Cheers

[Roger Caffin]

> Edvin's machine appears to have a horizontal bobbin.
> My machine and every one that I have ever used had vertical bobbins.
> Does this make a difference?
Not really. Both work fine.
The difference is partly historical, partly legal/patent issues.
I think Singer created the vertical bobbin, while ELNA introduced the horizontal bobbin – I think.
Don't ask the vendors though: they will all tell you their's is much better.

Cheers

[Author]

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