Your bobbin case gets a lot of use in your embroidery machine. Think of it like your car. You maintain it by keeping gas in the tank, changing the oil and washing it on a regular basis. For bigger problems, you have a mechanic look at it and if needed you replace parts.
Your bobbin case and bobbin area on your machine needs to be maintained by cleaning and applying oil on a regular basis. Through use, the bobbin case that holds your thread can become damaged if you have dropped it or you might not be able to adjust the tension to your normal setting. So the case might need to be replaced with a new one. I have had bobbins work one day and the next day when I turn on my machine, they are extremely loose on the tension. After cleaning and trying to adjust them with no success, I will usually put them through my Bobbin Tension Gauge to see if the thread pulls off smoothly. If I see any jumping or uneven movement of the bobbin in the case, it is an indication the case may be warped or "Out Of Round".
A good clean bobbin with tension adjustments appropriate for your machine, thread, fabric etc will usually produce even separation of color. This example shows the upper thread on the outside blue color and the inner white bobbin thread.
A dirty bobbin can cause the middle or bobbin thread to look very jagged. When I see this in my stitches, especially satin, I will normally pull the bobbin thread out of the case and clean underneath the tension area with a business card. Sometimes that is all it takes along with using your tension gauge and adjusting the small screw on the side. If all of this fails, you may have a bobbin case that is out of round from wear or being dropped. It doesn't take much as the small metal flanges on the side are thin. You will feel a wobble when you pull the thread off the bobbin.
It is a good idea to keep extra bobbin cases with your machine spare parts. They aren't expensive and you can find the part number through your manufacturer or dealer. Another place to look is your owner's manual. I have a video below you can watch that shows how to clean the tension area and what the bobbin will look like with a wobble. This one was replaced and my machine is back to smooth stitching. I hope you have enjoyed this post, share what you learn and are generous with what you create. Someone will appreciate your hard work.
