Hi,here is a detailed solution to help you solve the problem you are encountering with your sewing:
If you are using an old machine,the feed dogs could be worn,but if the feed dogs are not worn,here is another tip to help you,
check that the upper thread is not stuck or caught on something,preventing the thread from unwinding off the pool.
Now,check that you have properly fed the upper thread through all the guides,after a visual check with the presser foot down,pull gently on the free end of the top thread to see if its running smooth and clear,perform the same test on the bobbin thread,if either of them feel like it's caught or not unwind smoothly, check your instruction manual to ensure you are threading the bobbin and the machine correctly.

Next,remove the top thread,bobbin and the needle,with no thread or needle,try sewing the fabric,observe if the machine will feed the fabric under the presser foot,if it does you may need to increase the spring tension of the presser foot a bit.

Thanks and good luck

Hi,the solution is possible, The answer is a little bit long, so i will give you a link to get the manual on how to adjust the sewing machine.


ca.uky.edu/HES/fcs/FACTSHTS/CT-MMB-213.pdf.

Take care.