<!-- from fixya rte -->I need to see how to rewind a bobin. - Singer 3116 Simple

I dont have a fancy machine but any time Ive experienced this problem I do 1 of 2 things. First I check for bits of thread stuck inside till I removed the bobin case again and discovered the thread way underneath there. Second, if that didnt fix it I rewind my bobbin. Dont know if either would work in your situation. Good Luck.

Try using a can of compressed air in the hole where the bobbin winder pin sets and then push back in operating position. Also, take out bobbin holder under the metal plate below the needle. That entire assembly should come out and go back in easily. Again use the compressed air to get any fabric fuzz away from moving parts. Check your manual or online for oiling instructions. Hope this helps.

That is a problem with the high/low transmission. The screws that hold the winder post have slipped and the post pushed in to gearbox. The assembly needs to be taken out of the machine and rebuilt. A viking repair person who has been at it for a while might be able to repair this. You may need to look around as this is a repair that is not needed on machines made after the 70's and a lot of current repair people would not know how to do this.

if the bobbin winder spindle will not return to it's original position, then there's a part in the machine that not working correctly, & it needs to be serviced,

yes something is wrong with the machine , it needs to be repaired

You should be able to get a bobbin winder from any Singer shop and most dealers

just a thought but maybe your bobbin thread is wound on to loose,try to rewind it holding onto the thread to give a tigher tension while going onto the bobbin

Unfortunately, having done all the right things to do in that situation to elminate potential causes, it is most likely at this point that the machine has been thrown out of time, which is going to require professional help. The only other thing you will want to check is to take the hook out of the machine (that's the piece that your bobbin case fits into) and see if a needle stricke may have caused a rough spot on it, which could be catching the thread and causing your "clumping" situation.

You can try adjusting your stitch length this may solve the problem right away.
It could be the thread your using, I have had to switch threads before. Rewind your bobin, sometimes issues can occur by a poorly wound bobin.
You can also try to use a different foot (my machine comes with a satin stitch foot)and or slow the speed of your feed dog.
Sometimes a very fabric does need some sort of backing, a tear away, or wash away might be your only answer.
I hope this helped.

Try changing your needle.