Thread Tension Adjustments

[ChimeraKennels]

I understand that, generally speaking, if you see knots on the bottom then the tension on the bobbin side is tighter than the upper needle side...and when you see the knots on the top then the tension on the top is tighter than it is on the bobbin...but my question is when these adjustments are not set correct and out of equalibrium...how do you know if you need to loosen the one that is too tight verses tighen the one that is loose.

Right now, I am getting some build up of thread on the bobbin side...which I thought meant my bottom was tight or my upper tension was loose, but if I grab the tails of each and pull them...it is much easier to pull slack from the bottom than it is from the top. If anything the bobbin would seem loose to me and the top tight, but my knots and some extra are in the bottom.

Edited June 7, 2012 by ChimeraKennels

[CowboyBob]

I understand that, generally speaking, if you see knots on the bottom then the tension on the bobbin side is tighter than the upper needle side...and when you see the knots on the top then the tension on the top is tighter than it is on the bobbin...but my question is when these adjustments are not set correct and out of equalibrium...how do you know if you need to loosen the one that is too tight verses tighen the one that is loose.

Right now, I am getting some build up of thread on the bobbin side...which I thought meant my bottom was tight or my upper tension was loose, but if I grab the tails of each and pull them...it is much easier to pull slack from the bottom than it is from the top. If anything the bobbin would seem loose to me and the top tight, but my knots and some extra are in the bottom.

Lee,

Try to tighten the top tension a turn or 2 & see what happens.

Bob

[dbusarow]

Your top tension needs to be a lot tighter than the bobbin. The tensions need to be balanced, not equal.

Dan

[ChimeraKennels]

Thanks. Are there any general rules that I should be familiar with?

If you go to a larger thread what type of tension adjustment is generally needed? If you use it thicker material what type of tension adjustment is generally needed?

Thanks.

[Northmount]

Thicker thread needs more top tension to pull the thread up into the leather. Just because the thread is thicker doesn't make the top tension increase enough to do it. You have to add more top tension. If the leather is thicker, and you want to pull the thread (knot) further up into the leather, guess what. You need to increase the top tension a little more.

Don't start fiddling around with the bobbin tension unless you absolutely need to. Then follow the manufacturer's instructions with how much force is required to pull the thread through the bobbin tension spring. There are other threads/posts on LW about setting bobbin tension.

These tension settings, the reasoning behind them are common sense if you look at what you are trying to do with the position of the knot. Larger hole, easier to pull into, harder leather, harder to pull into, etc.

CTG

[Wizcrafts]

Thicker thread needs more top tension to pull the thread up into the leather. Just because the thread is thicker doesn't make the top tension increase enough to do it. You have to add more top tension. If the leather is thicker, and you want to pull the thread (knot) further up into the leather, guess what. You need to increase the top tension a little more.

Don't start fiddling around with the bobbin tension unless you absolutely need to. Then follow the manufacturer's instructions with how much force is required to pull the thread through the bobbin tension spring. There are other threads/posts on LW about setting bobbin tension.

These tension settings, the reasoning behind them are common sense if you look at what you are trying to do with the position of the knot. Larger hole, easier to pull into, harder leather, harder to pull into, etc.

CTG

That was a great explanation. However, the OP is not sewing lather. He is sewing webbing. Still, the same principals apply. To overcome the resistance of the dense and thick material, you need more tension on the top thread. This can be achieved both by tightening the beehive upper tension spring, and/or by wrapping the top thread around any posts on the top of the machine, ahead of the upper tension disks.

While increasing the needle size does help bring the knots up in leather, it probably won't have as much impact in webbing. But, try it anyway. If you are trying to sew with #138 bonded thread, using a #22 needle, substitute a #23 needle. It can't hoit!

If you think the bobbin spring is too tight, loosen it a tad. It should feed smoothly, without any herky-jerky motion. There needs to be a modicum of bobbin tension to ensure consistency of the bottom stitches and knots. You balance the top tension as needed, with the adjuster, or extra wraps around posts.

[ChimeraKennels]

Are there any "sewing 101" topics?

I'm making a little progress here fine tuning the tension adjustments. Still have some work to do though.

The bobbin was feeding smoothly, but I loosened it VERY slightly.

The top side was where I was getting the "herky jerky," but I didn't realize the pressure plates on the tension adjustment were relaxed when I raised the feet by the hand lift...and then tighter when I lowered the feet back down. Now that I realize that, I don't see as much "herky jerky" and am seeing more consistency in the tension.

Please recall...I had no issues on the test runs when I bought the machine, but that was with 69 thread and a 160 needle (which I would think would be large...but that is what was in it). Whatever problems I am having my guess is either a product of changing thread or getting the tension adjustments out of calibration when I was cleaning the unit...in other words.a product of my doing...and I realize this...so straight forward recommendation are appreciated.

I ordered a few new tension discs thinking clean ones would be beneficial, but the "U" cut out on the edge wasn't deep enough for this machine for them to fit so I had to use the old ones.

I realize the 140 needle is the 22 needle...at least those are the numbers on the needle holder package. Is the 160 a #23 needle? The package that says 160 is an old package and doesn't have another number on it (other than the 190...which is the length needed for the pfaff 145 machine I suppose).

Anyway, with 138 thread I received, I requested some needles...and received size 140 needle, so I assumed that was the needle I should be using...but when using the 140, I noticed some twisting in the thread in the needle and some cut strands (and I broke two needles while working through this)...which leads me to believe that needle is too small or I had my tension too tight for a while.

Most of my problems occurred when backtacking...but I lengthened the stitch length and that seemed to help some. My guess is I may need a more aggressive feed dog for the thick nylon layers. Thoughts here?

I put in a 160 needle and made some tension adjustments and a few more test runs...and things have gone better since, but I have only done a little sewing since. It is late now, so I will check back here for other tips, and try some more tomorrow.