Original text by: Marina Belova
One would think that evaluating of tension of the thread is such an old chestnut. But no, last week it came as a revelation to me. It is strange that such an essential information is practically non-existent on the internet, whereas manuals only contain the instructions on how to do the most basic things. And it is such a shame, really.
So, everybody knows (including me) that after the embroidery has been completed, the backside of a perfect satin-stitch column should look like this: 1/3+1/3+1/3 (upper + under + upper). If the column is divided differently, it means that you need to adjust your upper thread tension or the under-thread tension on your bobbin case.
I shall be honest with you, I don't see this ideal picture often, certainly not all the time. Velles 15 is notorious for getting the thread tension wrong, of which I've written many times, and was supported by the others. But there is a problem with the dial itself, which is pretty crude and, consequently, lacks the possibilities the Velles 19 dial has. But no matter how the dial was made, you have to adjust it all the time.
The question is, how do you do it? Sometimes it's quite difficult a task to adjust it properly.
As it happens, you have to act wisely.
First of all, I'll show you the most typical occasion which happens all the time when I use my Velles 15, and which has always puzzled me. These are my real works, not the test pieces:
As it turns out, this irregular outcome of the bobbin thread is a mark that something is wrong with a bobbin case. Is it either bent or damaged.
To check this just lay the bobbin case with the bobbin inside onto the table or any other flat surface with bobbin facing down. Then pull at the thread, holding the case slightly and allowing the bobbin to uncoil freely. It the thread is not uncoiled smoothly, but jerkily, it is the sign that the bobbin case has been damaged, so that it is not round anymore. Most likely, it was dropped on the floor in the past. I have dropped it, of course, even more that once, but I never thought about the consequences.
To cut the long story short, you must have a spare bobbin case. Sometimes the jerking like that cannot be corrected in any other way.
And now I'll tell you about two of the most typical examples.
a. The under-thread is just barely visible on the underside or not visible at all:
In this case you will have to find time to run your machine through all those tension tests at least once to find out what happens with every one of your needles. Here you can also see the perfectly emblematic old photo of the old I-test from the times when I already had huge problems with a bobbin case.
It turned out, to my surprise, that there are two ways of adjustment in this situation (this nuance of evaluation of the test results is hardly mentioned at all):
• If such is the situation with all or nearly all of your needles, loosen the under-thread tension.
• But if this happens only with 2 or 3 needles, tighten the upper thread on them.
b. The under-thread on the underside is more than 1/3 column wide):
Again, run your machine through all the tests using every needle and see. And again you can get two different results:
• If such is the result produced by all the needles, tighten the under-thread tension.
• If you get it only with 2 or 3, loosen the upper thread.
That is basically all. I didn't know that it was so easy and used to regard thread tension tests with disdain. One should love their embroidery machine and care about it, so that it could reciprocate and minimize the number of unpleasant moment in the course of embroidery.
We have so much yet to learn.
P.S. A thought just popped in my head: what about single-thread embroidery machines that don't have a lot of needles, which can help you to compare their performance and understand what tension needs to be adjusted? How do you adjust the tension there?
Some of my readers suggest buying a special device that helps to adjust upper and under-thread tension. And what do you think?