Thread Tension Adjustment
Embroidery machines tensions are not difficult to adjust as long as you go about it in a logical and systematic way. The first thing to do is adjust all of the bobbin thread tensions so that they are correct & all the same - then you adjust each needle thread tension to suit the bobbin tension.
Adjusting The Bobbin Thread Tension
THE ACCURATE WAY
If you're not an experienced machine operator then the easiest way to accurately set bobbin tensions is to use a Bobbin thread tension guage. (Please call for info). This handy device will accurately show how many grams of force are required to pull thread out from the bobbin case. It is quick and easy to set all bobbin tensions so that they are exactly the same.
Please note: Bobbin tension setting guages can be purchased from Embroidery Source. Call 1800 137670
THE 'TFAR' METHOD (That feels about right)
Thread up the bobbin case as normal with a full bobbin then hold the end of thread between your thumb and fore-finger and let the bobbin case with bobbin hang by the end of the thread.
Now bounce the bobbin case up and down a gently whilst holding the end of the thread. If a little bit of bobbin thread is released from the bobbin each time you jig it up and down then that is a good starting point.
Some machines like Barudan's round turret models can usually be set to operate very well with lighter tensions whereas other makes may require a higher bobbin thread tension setting
You can increase the tension on the bobbin thread tension spring by turning the small tension screw clock-wise by about 1/4 of a turn each time.
Bobbin Tension Problems
1. - THE BOBBIN TENSION IS VERY UNEVEN
An uneven or erratic bobbin tension can be caused by using low quality bobbin thread which is not of a regular or even thickness. In some cases it can also be caused by poor quality needle thread.
Try a different thread!
2. - THE BOBBIN TENSION CHANGES IN A VERY REGULAR WAY - LIKE A WAVE
This is most likely caused by a damaged bobbin or bobbin case. If the bobbin or bobbin case has been dropped and is slightly bent, then the bobbin will touch the bobbin case once every revolution. When it touches - the bobbin tension increases then decreases again.
Change the bobbin case and/or bobbin
3. - THE BOBBIN THREAD PULLS UP TO THE TOP SURFACE
The bobbin thread tension is too loose
The needle thread tension is too tight
The needle thread is threaded incorrectly
The needle thread is catching on the cone or thread stand
4. - I CAN'T SEE ANY BOBBIN THREAD ON THE BACK - ONLY NEEDLE THREAD IS SHOWING
Bobbin thread tension is too tight
Needle thread tension is too loose
Tip:
Remember - if you have a tension problem which is affecting only one needle on a multi-needle machine then the most likely culprit is the needle thread tension. If it was a bobbin tension problem then it is likely that all of the needles on that head would be affected.
We often find machines on which the bobbin tensions are set much too tight. Why? Well it might just be because it's easier for the machine operator to tighten just one tension (the bobbin) than it is to loosen up to 15 separate needle tensions. It's a quick fix but one which ultimately leads to increased puckering, thread breakage and possible registration problems too.
Adjusting The Needle Thread Tensions
Once you have made sure that all of the bobbin thread tensions are set correctly then you can go about adjusting the needle thread tensions.
Remember that needle thread tensions may vary a little (or a lot) between different makes, thicknesses and qualities of thread.
The rule of thumb here is:
Find a good quality thread which provides smooth and consistent tension throughout the entire cone and throughout the shade range if possible.
It's good to have a tension test design which has the same number of colours as your machine. For a 9 colour machine - a small, fill stitch square with a fine satin stitch border, repeated 9 times. This is good because it allows you to check the tension on both fill stitches and on fine satin stitches too.
NOTE: Setting the tension for a wide satin stitch column may not provide you with the correct tension for all stitch types and widths such as fills and narrow columns. Check the tension on fill stitches AND on narrow columns too. If it is good for fills and narrow columns then it will be good for everything.
