please help!! trouble with my bernina

[warthog]

i bought my lovely bernina last year, successfully sewed a few things on it and then had a baby. i think my brain has turned to blamonge because for the life of me i can't get it to work.

what's happening is the lower (bobbin) thread doesn't seem to be working properly. the top thread is catching it but somehow the lower thread isn't pulling out well and is either making huge amounts of thread pile up on the back of the fabric or it's not catching the top thread at all.

i've quadruple checked it's loading, and whether the bobbin is going clockwise. i can't see where the tension setting for the bobbin is, but i've got the main tension dial on the factory setting.

i've run out of ideas!

can anyone help me please?

New needle? My advice was to use a new needle for each project, and it does seem to make a difference. Though I also suffer from a similar problem sometimes with my ancient Brother machine.

warthog that's your tension, it's too loose on the bottom/not tight enough on the top. Google your model number and see if you can find a manual, it should tell you where to find your tension dial x

Alternatively, if it's an auto-tension, you could be threading it wrong and missing out the tension catch iykwim - again, see what your manual says :)

the needle's been barely used - to make one dress and take up a few hems! wow - i'm going to be buying a lot of needles...

Sn0wGoose thanks very much - it does sound like the bottom tension is too loose. i have a manual. and i have read it - promise! - but i'll read it again.

thanks so much for the help. i'll give it a go when the kids are in bed.

You are supposed to use a new needle for every project :)

Is it an old or new model?

I have an ancient model - she is quite particular (as one gets with age) and does not like cheap thread or certain brands so I tend to stick to Guttermans.

Also it might be worth your while, taken out all the bobbin holder bits (shuttle I think the technical term is) and then putting them back in. I used to store my 'nina in the same cupboard as the hoover & I found that I was always having to do this as the case would get knocked when I was getting out/putting away the hoover & that would knock the bobbin shuttle out of place, ever so slightly but enough to cause problems.

a couple of troubleshooting links I had bookmarked.

sewing.about.com/od/sewingmachineindex/a/mtroubleshot.htm

sewandserge.com/tshoot.asp

thanks very much all! i'd better buy a few needles.

it's a new bernina (well, bought last year so a year old).

i have solved it.

there were two problems

1. the fundamental one was that i hadn't threaded the needle thread properly through the tension loop thingy. despite insisting that i had and having read the manual 7 times.
2. the bobbin case spring was too tight and my mil (who has an ancient bernina) explained how to get it right. none of the info she gave me was in the manual so quite how you're was supposed to fix this, who knows...

but i can now forge ahead with making my cot bumpers with fake hand-quilting stitch

so thanks very much to all of you for taking time to answer me.