Sewing Machine Tensions can be balanced by yourself, but you need to understand the number one mistake most sewers make. When trying to do this there is one simple thing to remember.
The first thing I always do when I get a machine on the bench is clean the top tension discs out. This is very easy to do and takes very little time. Find a piece of non fuzzy material about 8 inches long and 2 inches wide (soft material will work best, like a non fuzzy cotton).
Next, raise the press foot so the tension discs are open. This will allow you to get your material inside of them and clean any fuzz or thread build up that may be done between them (look inside where you thread your machine through the tension if it is not right on the outside).
Now, with the material held in a position that you can run it back and forth or up and down you are ready to clean the tension. Put your material inside of the disks and move it back and forth several times. When you are done with this, simply take a deep breath and blow hard right into where you cleaned. Make sure your top tension is set between 4-5 or right in the neutral position and you are done.
Depending on whether your sewing machine has a drop in bobbin or snap in bobbin the actual cleaning to do will be the same, but I will try to separate them for you. With a drop in bobbin the needle plate and bobbin case have to be removed from the sewing machine. Next, clean any debris built up on and around the shuttle. A q-tip generally works well for this. Now, place a drop or two of oil right in the center of the shuttle (the shuttle is what you put your bobbin case in).
Check to make sure the feed dogs do not have any built up debris in between them (the feed dogs or what feeds your material). If you see any build up simply take your old sewing machine needle and clean it out. Reassemble the machine, put a new needle in, thread it up and the machine should be ready to go.
For a snap in bobbin the cleaning is basically the same. The needle plate does not have to be removed, but it should be, simply to check for build up in between the feed dogs (the feed dogs are what is moving to feed the material). If you see any build up in between them take your old needle and clean it out. Remove the bobbin case retainer ring and bobbin case.
Cleaning The Bobbin Case Area – Snap In Bobbin. Just as in a drop in bobbin clean any build up out with a q-tip. Place a drop of oil above the half moon shuttle and reassemble the bobbin case area. Put a new needle in and you should be sewing away! (Make sure the top tension is set between 4-5 or right in the neutral position and you are done).