Are all three the same thread? Have you wound bobbins with this thread before? I have noticed that certain threads are more prone to winding unevenly. And just to clarify, do you mean that as the bobbin winds, the thread keeps wrapping in the same spot instead of moving up and down the bobbin as it should? If that is the case, you can just use one of your fingers to guide it up and down on the bobbin.

Double-check that you are threading the guides correctly. Also, make sure there aren't any fuzzballs or pieces of thread caught somewhere in the threading/winding mechanism.

My machines sometimes get the thread wrapped around the bobbin winding pin below the platform the bobbin sits on.

Donna

Yes, as the thread is being wound, I can see that the thread keeps getting thicker on either the top end of the bottom, and somehow goes crisscrossed. Thus, some thread are very loose and make big loose loops around the bobbin

I suggest that you take bits from both msmeow and my advice. Make sure you are taking the thread in the correct direction around/through the guides and keep your index finger ready to help guide if necessary. Also, if you start and stop while you are threading the bobbin, this can cause a backlash, which will loop the thread. One more thing - try winding at a lower speed, but keep it continuous. Oh, and I thought of one more thing. If these bobbins are new, are you sure you purchased the correct bobbins for your machine?

Yes, I will take both of your helpful advice. They are not new, and they worked properly before. I guess perhaps I had not winding the bobbins for so long; the direction might be wrong now. Thank you much

Does your machine winds the bobbins in it's case or are you having to wind on the bobbin winder on the outside? If you are winding on the outside make sure your bobbin is "seated" on the little pin on the winder. If it isn't snapped onto the pin it can spin freely when you go to wind it. My bobbins have a little notch cut out of them around the hole that goes on the winder. That's where the little pin should fit. I hope I am making this clear. I can see it. hahha

thanks Frances. Yes, I see what you meant. Mine winds outside