Singer model 518....the material won't feed through.It wants to sew but won't feed cloth through. Thks
Be sure you have the stitch length set high enough that the fabric will actually move instead of sewing mostly in one spot.
One other thing to check is the presser foot applying enough pressure to the fabric so that the feed dogs can grab the fabric? On the top left side of the machine, there is probably either a dial or a push-type button. That would most likely be the pressure adjustment. The tighter that is set, the harder the pressure the presser foot will apply and the more the feed dogs will grab the fabric.
Check that the feed dogs are in the "up" position so they will pull the fabric through the machine. Are the feed dogs actually moving forward, raising above the needle plate, pulling toward the back of the machine, and then dropping below the needleplate before moving forward again? If not, then the problem could be with the feed dogs.
Your machine appears to be a mechanical model. If so, it could be the machine needs a good over-all cleaning and oiling--a couple drops of fresh, good quality sewing machine oil every place that metal rubs on metal (no plastic parts, belts...). Feed dogs are frequently affected when the sewing machine does not receive regular maintenance.