Hello, are you some of the many that are having problems with getting their thread tension set proper or are having trouble getting the top thread tension adjusted to the correct tightness or setting. I have helped several people in finding out what their problem was and most were to the point of just putting the machine back in storage because they just could not get it to work. I had a lady who had not sewed in many years she purchased a machine from me and when she got it she set the machine up and threaded it put in a bobbin and began to sew. She noticed that the top thread tension was not tight and so she adjusted the tension but it stayed the same so she went back through the manual step by step and could not find the problem. This poor lady was ready to pull her hair out, she emailed me and I gave a few suggestions still she was still having problems, I gave more suggestions, to make a long store short it was that she had her bobbin in backwards.
I am going to tell you a few things to check if you are having problems with the thread tension.
1. Thread weight in spool and bobbin may cause tension to be different
2. Make sure you have the machine threaded correct
3. Make sure thread is going through the wire or spring correct on tension
4. Make sure needle is inserted correct flat side of needle facing correct direction for the machine you are using (they are different) and that it is a new needle or that it doesn’t have a hook or point is flat, this can cause stitch skips and more problems.
5. Make sure the little finger on rotary is in space on needle plate; if this is not correct can cause all kinds of problem.
6. When putting the bobbin in the bobbin case make sure you put the bobbin in so the thread comes off bobbin clock wise and that the thread is pulled into the slot on the spring of bobbin case if this is not correct it will cause loose stitch because the spring is not doing its job. You may also need to adjust the little screw on the bobbin case and I have received machines and the bobbin case has buildup inside the case and causes the bobbin not to turn free.
There are a lot of little things that can cause your tension not to work correct and cause loose stitch, skip stitch, thread to bunch up so remember to look for these little things and if you are still having problems make sure your machine is clean and that the rotary, bobbin case, thread tension parts are not missing or have broken parts (I had one machine that the hook on the rotary had a very little peice of the hook broken off). If you still can not figure it out I am willing to give it a shot just email me or I am willing to take a look at your machine if you like.
I have parts available for your older Singer machines take a look at my website;
http://singeroriginalvintageproducts.com/singerfeatherweight221machinesewingparts.aspx
Also eBay; duane_sec45bottles&more
I hope this helps,
duane