I back with another problem. Actually I thought I sent this post a while ago but I must have forgotten to hit the "send" button - so here goes again.

I have wound about a half dozen or so bobbin and have had trouble every time. I do it just like the diagram on the machine and the pictures in the manual but it doesn't work for me. Every time I have a problem with the thread winding UNDER the bobbin. I take it off and try two or three time before it winds correctly. What could I be doing wrong?

Thanks (again)! New 6600 owner

Maybe the bobbin isn't completely seated on the machine before winding? I don't have a Janome but when I'm not paying attention, I won't get the bobbin seated on the winder correctly and the thread can and will wind underneath it.

Did you actually read the manual? Maybe you missed a step.
Do you push the bobbin down until it clicks? Then, do you push
the spindle to the right before pushing the winding button?
Finally, are you using Janome bobbins?
If you're still having problems after carefully following your manual,
may I suggest you contact your dealer for help.

I have the same machine. All the advice above is what I would have said. Only a few other things I would add.

Is your thread antennae(that's what I call it) in the upright position?

Do you have the thread threaded in only three spots before putting in the bobbin hole on the spindle to wind? Follow the dashed lines on top of your machine to thread.

When I begin winding the thread, I hold onto the tail for several turns, stop the machine, trim the tail right down to the bobbin top, start winding again.

It sounds as if you have too much thread loose before winding it. This is going to sound funny to do but it does work. Once I thread my bobbin and put it on the little spinal I take the thread and pull it tight - hit the winding button. Once its gone around a couple of times I stop the winding and snip the thread then continue winding it until its done.

There's a really small hole on my bobbin that I put the thread through and wind it a couple times like the other ladies. I hold that thread tight as it winds a few times, stop and cut it off flush with the bobbin and then continue winding. But I think you said your problem was thread winding beneath the bobbin so I'd suspect not seating it correctly first, but all the suggestions are sound ideas.

I had this happen once, but hadnt seated the bobbin properly. Like Sewcrafty said, you must not have any loose thread either or it will do the same thing.