Sewing machine fault

[storynanny]

What else can I try before calling in the experts? Bobbin underneath thread bunching in clumps. Tried new needle, cleaning out the bobbin case etc, rethreaded etc but still not working properly. I was sewing away happily and there was a crunching sound, but not needle breaking or pin caught so don't know what the problem is.

Check the tension.
Is it the right bobbin for the machine.
Are you using cheap thread

Haven't changed the tension, same bobbin as always and gutermann thread as usual but thanks anyway.

Has it jammed for some other reason before the fault? You might have a fiber caught in the bobbin cradle - my very old machine had a paddy for years until I started needing reading glasses. It was the smallest fragment of cotton.

What sort of machine is it?

I would google 'cleaning the underneath of X machine'.

I can take mine apart to clean it all, I wonder if you can do the same. Usual checks are needle, threading, bobbin winding, is it in correctly and tension. If that fails you won't hurt anything by googling as above.

I haven't watched it so it could be rubbish but this is the sort of thing I get when I google my machine.

Try checking the tension on the bobbin holder, there is a little screw which is turned to adjust it. Before you do that though hold the thread of the bobbin and gently drop it it shouldn't fall to easily or not move at all.
Out of interest, what kind of machine is it ? Does the bobbin go in at the front of the machine or from the top.

It's an Elna, 2600 , about 7 years old. I've taken the bobbin case out and I think it's something to do with that so will have another poke around tomorrow, got to stop now as I am nearly ready to throw it out of the window!
Thanks for all your help tho.
The bobbin goes in the top.

I’ve bought a fab new one and now wonder why I struggled with the old one for so long!