Why is my thread not picking up from bobin, jones old shuttle machine?

SOURCE: I have a Brother SE-270D

its the problem of the timing belt in your machine its extra loosen or extra tightned or is slightly came out of its position or finally broken.
as the machine is proper just missing the proper speed as it should be .
it is running continuosly as you stated.
check the timing belt and make it proper if its worn out and needs replacement this is how its done

There is an adjusting screw on the right side of the machine head. Follow the motor bracket to the machine head and loosen that big old screw or bolt which will raise or lower the motor giving you slack to remove or replace the belt.

feel free for further queries
thanks

SOURCE: Top & bobbin thread will not sew

Most likely the needle is in backwards. Weird I know, I have no idea why but if the needle is in wrong, it either hits the bobbin and breaks or won't grab the thread at all. Good luck.

SOURCE: Brother sewing machine vx1120 Ithink won't pick up bobbin thread

have you tried other thread and a different bobbin?  The tension screw on the bobin case could be too tight.

SOURCE: how to stop bobin thread from knotting

When loading the bobbin there is most likely not enough tension on the thread letting it overlap incorrectly. Try wrapping thread around a tensioner when filling and that should help. That way the bobbin is rolled as tight as the tension on the upper thread when sewing.

SOURCE: Brother VX-1120- The needle is not picking up bobbin thread.

I had the same problem with my brother vx-1120 sewing machine. I set the needle to lowest position by using the hand crank. Then I loosened the knerled set screw that holds needle in place. Then I moved needle shaft till the eye of needle is just lower than the hook on the shuttle loop maker. It made my mechine work. There are instuctions for ajusting timing on machine but I think these mechines are built to not fix and throw out. Just because there where no ajustment marks at all on machine, any machanical machine will needed to be ajusted sometime.