toxo Report post Posted January 16, 2023 When the stitch is unbalanced and there's a choice to tighten one or loosen the other is there a criteria for which way to go? I'm thinking of maybe too much of one or the other may damage the machine? Quote Share this post Link to post Share on other sites
kgg Report post Posted January 16, 2023 (edited) 1 hour ago, toxo said: I'm thinking of maybe too much of one or the other may damage the machine? I think this is a good point for discussion. I think if the top tension is to much then it puts to much strain on the the take up lever and parts and if the bobbin tension is to much then the bobbin assembly is at risk of damage particularly if the machine doesn't have a safety clutch. I usually just adjust the top tension first if I am assured that the machine is threaded correctly, the bobbin tension is correct for the thread and the needle is new and correct size for the thread size / material thickness. What I do is: i) change my needle for a new project or after eight hours of use or the needle seems dull / struggling whichever comes first ii) refill my bobbin with new thread and do a drop test iii) test seam If I have changed the thread size or changed thread manufacturers I will: i) cut the old thread at the spool and tie the old thread to the new thread ii) remove the thread from the eye of the needle and pull the old thread with the newly attached top thread through to the needle from the needle side of the machine iii) install a fresh bobbin with the new thread size and do a drop test. iv) test seam. If the test seam shows the bobbin thread on top then I first back off the top tension and if the bobbin thread isn't pulled up properly then I increase the top thread tension. Do another test seam and if that isn't correct I adjust the bobbin tension by an 1/8 of a turn. kgg Edited January 16, 2023 by kgg Quote Share this post Link to post Share on other sites
Northmount Report post Posted January 16, 2023 @toxo Moved your post to leather sewing machines. Quote Share this post Link to post Share on other sites
Wizcrafts Report post Posted January 16, 2023 I try to keep the bobbin tension to the least that provides a smooth pull out of the case. Then I adjust the top tension to balance the knots. If I have trouble getting the knots up, I move up one needle size. If the larger hole is objectionable, I do increase the top tension. On some machines you can crank the top tension way up. On standard walking foot machines this can really stress the take-up lever and crank shafts. It also causes the top thread to snap as it goes around the shuttle on vertical hook machines (aka: Singer 1121, Consew 225, Juki 563). You can also add silicon lube, or even sewing machine oil to an oil cup if your machine has one. You can buy aftermarket lube jars that fit on top and get screwed to a top guide post. The thread runs through the lube if there is any in the jar. Quote Share this post Link to post Share on other sites
Quade Report post Posted January 16, 2023 Is there a good way to measure top tension to get some idea where you are compared to a "standard"? When they made these machines, did they have some max top tension in mind? Some number we can note and compare to the tension we have set? I guess what I mean is how can we know when we have too much top tension and it's then time to mess with needle sizes and/or lube? Quote Share this post Link to post Share on other sites
RockyAussie Report post Posted January 17, 2023 (edited) 23 hours ago, toxo said: When the stitch is unbalanced and there's a choice to tighten one or loosen the other is there a criteria for which way to go? I'm thinking of maybe too much of one or the other may damage the machine? There are a whole lot of varying factors that may need to be considered such as the thread take up spring pressure etc but ...to simplify this tension question, if the leather is thin or soft you would normally run light spring pressure on both the top and bottom tensions. If the tension is too tight it will gather the leather together. If you were doing firm leather then you would run a tighter pressure top and bottom. As a very rough guide on most machines you would start off by having your top tension adjustment so that the the screw adjustment was close to half way in. If you had say 9 full turns of adjustment untill you could screw in the top tension no tighter then the starting point ideally would be about 4 and 1/2 turns out. This then means that you have the most adjustment possible tighter or looser on the top tension. Once that is set you then set your bobbin tension so that it can be pulled out by hand reasonably easily to start with then test stitch and adjust until the bobbin spring pressure balances the knot consistently. This should give you a setting that for most leather only requires adjusting the top tension. The top tension is then way easier to adjust on the run if needed which is something I do when the thickness or stiffness changes on jobs as it does sometimes. Foot pressure is also important to adjust on the run sometimes etc. In this video I start with some fabric and the tension is tighter than it should be but not shown is where I tighten the top tension several times as I go up into the thicker stiff leather - Edited January 17, 2023 by RockyAussie Quote Share this post Link to post Share on other sites
