If you look at the underside of whatever you’re sewing and you can see that the top thread is being pulled all the way through, it’s too tight. Or the top tension is too loose. It’s a balancing act. The correct way is, the “knot” should be in the center of the material and not be seen.
Hi,
I have found that a Towa bobbin tension guage is really useful when setting your machine up. I contacted the manufacturers of my favourite thread(s) and saw that there is an optimum tension setting (usually in grms force gf) The Towa guage is calibrated in mN (milli Newtons). 9.81 mNewtoms = 1 gf. Use that setting for a baseline , before you start on getting your upper thread tension right.
Dave
up to now it has been Oxella 25 (by Amann-Rasant) - but I have decided to follow @John advice a drop down to the #92 he recommends.
Once I have used this for a while , then I will probably settle on Coates version of this thread.
regards
Dave
Woah! Thats cool. I have never even heard of one of these. Thanks for posting.
Amann is a really good brand as well. Id recommend using their serabond or serafil thread if want to stick with the brand. Coats is great as well.
They also do a digital display version - but it's a bit to costly for me (~ $200 US). I am also investigating the possible use of a load cell/strain guage to calibrate the top tension assembly so that I can save settings (for top and bottom tensions, needle size, thread type and material ) This will help me when I switch between different assembly jobs. That's the theory anyway :)
Dave
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