ericluther Report post Posted July 24, 2009 (edited) I had trouble setting the tension on my 31-15 and found this and it helped me ALOT, so I thought I'd share. Step One: If there are loops on top reduce your tension two dial marks. If there are loops on the bottom increase the tension two dial marks If there are no loops go to the next step Step Two: If it looks like sewing on the bottom, and just a straight thread on top, decrease your tension one mark. If it looks like sewing on top, and just a straight thread on bottom increase your tension one mark. If it looks like sewing on both sides go to the next step. Step Three: Look very carefully at the stitching, If it looks loose on the bottom increase the tension ½ the amount you changed it the last time. If it looks loose on the top reduce the tension ½ the amount you changed it the last time. Repeat until you can not tell any difference in the two threads. You programmer types will recognize that we and using a binary search to find the correct tension setting. For others what that means is we are moving the setting past what it needs to be and then back half way. We are reducing the error 50% or more each time we do that. Going from loopy to good enough only takes five steps; 2, 1, ½, ¼, 1/8. A couple of steps more and you are moving the dial only a hair and have it about as close at a really well set up machine will do because there is some slop in the train and it will wobble that much. You will also notice that correct tension is only about 1/8 a dial marking from incorrect. Make notes of what is correct with each needle/thread combination you use, and you will be able to set the dial close next time you use that combination. From there it only takes one or two steps to get it just right. link to full article http://tomrit.com/sewing/?p=40 Hope this helps someone! Eric Edited July 24, 2009 by ericluther Quote Share this post Link to post Share on other sites
Art Report post Posted July 24, 2009 Hi Eric, Is step 2 correct? Art I had trouble setting the tension on my 31-15 and found this and it helped me ALOT, so I thought I'd share. Step One: If there are loops on top reduce your tension two dial marks. If there are loops on the bottom increase the tension two dial marks If there are no loops go to the next step Step Two: If it looks like sewing on the bottom, and just a straight thread on top, increase your tension one mark. If it looks like sewing on top, and just a straight thread on bottom reduce your tension one mark. If it looks like sewing on both sides go to the next step. Step Three: Look very carefully at the stitching, If it looks loose on the bottom increase the tension ½ the amount you changed it the last time. If it looks loose on the top reduce the tension ½ the amount you changed it the last time. Repeat until you can not tell any difference in the two threads. You programmer types will recognize that we and using a binary search to find the correct tension setting. For others what that means is we are moving the setting past what it needs to be and then back half way. We are reducing the error 50% or more each time we do that. Going from loopy to good enough only takes five steps; 2, 1, ½, ¼, 1/8. A couple of steps more and you are moving the dial only a hair and have it about as close at a really well set up machine will do because there is some slop in the train and it will wobble that much. You will also notice that correct tension is only about 1/8 a dial marking from incorrect. Make notes of what is correct with each needle/thread combination you use, and you will be able to set the dial close next time you use that combination. From there it only takes one or two steps to get it just right. link to full article http://tomrit.com/sewing/?p=40 Hope this helps someone! Eric Quote Share this post Link to post Share on other sites
ericluther Report post Posted July 24, 2009 (edited) You know I must have transposed it in my brain, the one thing I did know is that if the bottom thread is loose then the tension needs to increase, so it must be backwards right? I will edit it. Edited July 24, 2009 by ericluther Quote Share this post Link to post Share on other sites
captkit Report post Posted July 30, 2009 Thanks for the method. I have also got good results by adjusting the bobbin tension. Especially to control the situation when needle thread looks fine but bobbin thread is a straight line. Quote Share this post Link to post Share on other sites
kjelgaard Report post Posted July 31, 2009 Learning to set bobbin tension was immensely helpful, especially when switching between bobbin threads. If you hold the case by the thread and drop the bobbin case, it should drop about an inch and a half. You can get by with just one case once you learn how to get it perfect. Quote Share this post Link to post Share on other sites
jnewburry Report post Posted November 24, 2009 Hi, Was wondering if the tension you are adjusting is the top thread tensioner? I am almost in business, I am able to join two pieces of leather together but the bottom is loopy on single layer of leather and not quite pulled tight enough on two layers. Thanks, jim Quote Share this post Link to post Share on other sites
