Q. I recently bought the Top Tension Pro (already had the bobbin gauge) for my HQ Sweet 16. Upon installing it I tried a lot of the threads and the results varied quite a bit. I realize that each machine is individual but there seems to be a huge difference in the number I'm recording. Another brand of polyester is reading 5-6 for me but on the forums other people have noted it reads 29-32. I need to know if this is normal or if I'm doing something wrong. Also, when I dial the numbers, it seems to lag to respond and often moves about.
The bobbin is Bottom Line thread with the TOWA bobbin gauge measurement of 190. Most of the threads I use are by Superior. I also only threaded through 2 of the 3 pretension holes on most of the threads I used.
A. Right off the bat I'd like to make the point that if you are getting a good stitch with the settings you're seeing (i.e. if the polyester thread you're using is stitching well at 5-6), then I wouldn't change anything. I've run all of our threads on our Handi Quilter Avante and have a variety of readings based on what threads we're using. I've found two things that affect the Top Tension Pro's reading more than anything else: 1) Thickness of the spring and 2) whether or not the thread is flossed between the tension discs.
1) If you have a thicker spring than others, your numbers will be lower, because there is more pressure being exerted against the tension discs and therefore it takes fewer rotations when tightening the tension knob to get a balanced tension setting. With so many different springs available, I do not know if all machines or brands use the same type. For example, our Gammill longarm has 2 springs, one is a light-duty while the other is thicker. If I use the light-duty spring, it takes many rotations and a lot of pressure to get a reading and is difficult to find the 'sweet spot'.
2) Sometimes thread will ride on top of the tension discs instead of being seated between the discs. This will definitely affect the readings.
How I use the Top Tension Pro on our Longarms:
I never thread through all 3 holes. I use 2 holes except when quilting with delicate threads such as Metallic or Glitter, and then I only pass through 1 hole. This allows me to have greater control of the top tension by how much pressure I have against my tension discs. After I have threaded the machine, I will manually 'floss' the thread between the tension discs to make sure that it is seated between the discs correctly.
Your bobbin tension measurements look great. Between the 180-220 range is good for Bottom Line. Once you obtain a good stitch balance during testing, turn off the Top Tension Pro. There's no need to keep the unit on once you have obtained a good stitch balance.