Singer sewing machines are one of the most commonly found machines for the home seamstress. They are relatively inexpensive and easy to run. They do have some common repairs that occur over their life time of use. You can easily handle most of these problems if you know what to look for to diagnose your problem.
Thread Loops in the Stitches
If you try sewing and find that there are loops of thread accumulating on the bottom or top of your fabric, you have a thread tension problem. This happens if you switch from sewing heavy fabric, such as denim, to sewing something lightweight like bridal veiling. This can be adjusted by either turning the tension knob or dial on the body of the machine to adjust the upper thread tension or by turning the thread tension screw located on the bobbin case carefully. Most tension problems can be repaired by adjusting the upper tension. Take your time and use a scrap of the type of fabric you wish to sew to check your tension. Make small adjustments to either tighten or loosen the thread tension while sewing on your scrap of fabric. Pause during stitching to make your adjustments.
Motor Belt Breaks
A relatively simple but common repair due to use is when the motor's belt breaks. Over time, a sewing machine's belts will crack, break or stretch. They are easily replaced, but you must make sure you purchase the belt appropriate to your machine. Take your old belt with you along with the make and model number of your machine to a repair store to compare with the new ones available or to show the shop owner. When you replace the belt, be sure you disconnect the power cord before you begin work.
Failure to Wind a Bobbin
Check to see that your machine is threaded properly if you have trouble winding a bobbin. Most machines have a specific thread route required to facilitate winding a bobbin. The thread must pass through a tension ring or your bobbins will wind loosely, be uneven and not work well for sewing. Sometimes the bobbin will not wind because the bobbin winding tire needs to be replaced. This is a small rubber tire that spins and drives the spool that you place your bobbin on to wind it. The rubber tires get old, worn and will often crack. They need to be replaced every few years.
Having your needles break while sewing can be a result of improper needle insertion, faulty timing, pulling on the fabric while sewing, sewing too heavy a fabric for the size needle or just having a dirty machine. Check that you have the flat portion of the needle appropriately positioned when changing your needle. Do not pull the fabric while sewing, gently guide it. Check to see that the needle is strong enough for the type of fabric you are sewing. Clean and oil your machine regularly. Remove all lint from the shuttle area and around the feed teeth. These need to be removed to get the lint that lodges beneath them. Oil the machine according to the specifics of your machine. If necessary, adjust the timing. If the timing is off enough, the needle will come down during the sewing stroke and strike the end of the hook, resulting in breakage.
Faulty timing of the hook is responsible for skipped stitches in most cases. This repair can be caused by the home seamstress if you are familiar with your machine and are comfortable adjusting major components. This easily occurs just from simple sewing, especially if you sew a heavy fabric and run from two layers to eight, due to seams. The change in bulk running through the machine can be enough to throw the timing off. Before attempting to adjust the hook timing, check to make sure your needle does not have a burr on it. This simple flaw can be enough to throw the stitching off. Replace the needle and check the stitching to see if the problem has been taken care of. If not, the timing will need attention.