I recently recieved a featherweight from a friend. It stitched well for about one row and then locked up. Is it ok to remove the screw at the left of the bobbin case to determine whether there is a thread caught in there???? I think the thread may be the cause of the stoppage.

Ok, I am looking at my featherweight right now and I am not sure what screw you are referring to..are you talking about the tiny screw right on the bobbin case at the side of the machine?

Try turning the wheel backwards. Some times this helps loosen up the threads that are stuck and you can see what is where.

turn the machine over. take off large "screw", lay bottom
plate aside. now you can look into the bobbin area & use
tweezers to get thread pieces. but first, take the throat plate off & check for thread pieces. IMPORTANT--read your
manual on how to put the throat plate back on---or you will
have another problem. when sewing, always a good idea to hold the threads at the back as you start to sew. and don't
turn the handwheel towards you.

Thanks I didn't know that either!!