The Perfect Stitch

[JWP]

Hi everyone, So is the perfect stitch when the knot created by the top thread and the botton thread is located in the middle of the leather you are sewing. That said, if the thickness of the leather you are sewing changes then the resistance changes proportionally both upward and downward so the knot would always end up in the middle of the leather. I have read that tention will have to be changed when you make a large change like from 4 .oz to 9 .oz . This doesn't make sense to me so any feed back would be appreciated. Also if someone has a better way to finish a stitch with out melting it with a lighter and making a mess out of it I would sure like to hear about it. Thanks in advance for any help.

[Narvi]

You can view stitch tension as a kind of tug-of-war between the top and bottom threads. If the tug-of-war is even, the knot, or more properly, loop made by the hook will get pulled up between the two layers of leather and be invisible to view. Sometimes, one or the other of the threads will be wining the war.

If the upper thread is winning, the loop will appear on top of the hole made by the needle, and very ugly it is too. In this case, the upper thread needs to be handicapped by loosening the upper tension mechanism. If the lower thread is winning the tug-of-war, the loop appears on the bottom of the material, so the upper thread needs a stronger hand. So the upper tension must now be tightened. Since the upper tension is easier to adjust, the lower tension should only be messed with if the upper tension is maxed out in one direction or the other and problems are still occurring. Under ordinary circumstances, this should not be the case. Try re-threading the machine and changing out the bobbin before messing with the lower tension.

All things being equal, more upper tension will be needed the thicker the material gets. As a rule, if you start sewing 4oz leather on a machine that has been sewing 9oz successfully, you will get knots on top of the material. The upper tension will have to be loosened to get a good result.