Thread Revisited
The base tension on these old sewing machines is supposed to be set up with #50 cotton thread, as I mentioned in a previous post about tension, but I could not find any in my area. Well I finally found some. Unfortunately it was in a big spool that I can not use on my machines. However it did give me a chance to compare it to the Coats & Clark Dual Duty XL that I get at Walmart. The #50 mercerized cotton thread is quite a bit heavier than the Dual Duty XL cotton/polyester stuff. Probably the Dual Duty XL is about the equalent of #60 thread, maybe even a bit finer, which most likely explains why it matches the 11 and 12 needles so well. Therefore using the Dual Duty XL, #12 sharp needle, and medium weight fabric as I did looks to be about the closest setup I have available for setting up the tensions (Note: I am writing here about the initial setup, not the adjustments for particular fabric, thread, and needle).
If you mean for sewing, I already have. Look for my Howto Set Your Tension post.
If you mean how to set up the dial, it varies from machine to machine. Basically you set the tension with the standard needle, thread, and fabric. Then you adjust the dial so it reads the proper number (4 on most Singer straight stitch machines). If you are using a finer thread and needle as I mentioned in this article then 5 would be about right. Remember, the finer the needle and thread the higher the tension, and vis versa.
Could you post a tutorial about setting up the tension on your machine?
Thanks