bobbin not winding right, help?

[cancat]

I bought a used viking for very cheap at our local thrift, and it sews great, but the bobbin doesn't seem to wind right no matter how I thread it - it's all lumpy and randomly tight and loose, and doesn't go up and down in any order. Does anyone have any suggestions for what I can try to fix it? I'd take it to the repair shop, but that would probably cost more than the machine did, so I'd like to try a few things at home first...

if no one knows any tricks, does anyone have any suggestions for websites that have general repair tips? I can't seem to find anything that's not very brand-specific (and this is an old viking)...

[elanorh]

My hunch would be that the tension feeder that you should be looping the thread around en route to the bottom either is missing or doesn't work. Do you have the instruction manual with the machine, too?

Have you tried holding the thread in your hand and using your fingers as the tension for it to pass through en route to the bobbin?

Is it possible that you're missing a small part (i.e., the button which secures the bobbin for threading) and that's making the difference?

[sapphire_chan]

You can control the up and downness of the wrapping by taking a pencil or other rounded stick and just using that to control the thread as a replacement for the button if it's missing. That also helps to get the thread started--I find that on my machine the thread tends to want to start wrapping beneath the bobbin if I don't give it a boost to start it off.

[sabrinat]

Hmmmm. the thing that makes the bobbin winder go around smoothly, sometimes called a tire...how does it look?