Tight thread tension on top loose on the bottom

[jadub]

Hi, I have a Pfaff 1245 with what appears to be tension issues. The bobbin thread won’t snug up unless I have the top tension  so tight every knot is pulled through and the top thread basically lies flat across the leather. If the knot sits somewhere in the middle of the leather the bobbin thread is loose and even a little wobbly. Thank you for your help!

[Wizcrafts]

First, try flipping the bobbin around, reversing the bobbin thread's direction. I usually feed my bobbin thread against the direction of the slit under the spring. This ensures that the thread goes and stays under the tension spring. But, if the thread is difficult, feeding it inline might help.

[kgg]

2 hours ago, jadub said:

Hi, I have a Pfaff 1245 with what appears to be tension issues.

This could be also be related to the size of needle, size of thread, thickness of leather. What size needle, thread and thickness of leather are you using?

kgg

[jadub]

I have switched the bobbin thread direction. Yesterday it came to me in a flash that maybe I had it in wrong. No luck. Still wonky.

The needle is a 130/21 with 138 thread. I believe it may be pushing it but within spec. The leather thickness varies as I sew the wallet depending on how many layers are being sewn. Not more than1/4” at the most.

Thank you for the thoughts. I really appreciate it.

Just so you know, I’ve also tried different thread, a different needle, rethread the machine, new thread in bobbin and maybe a couple of other things. Today I had it working on several lines of test stitching but I sewed a wallet and the bobbin side was wonky again.

[kgg]

22 minutes ago, jadub said:

The needle is a 130/21 with 138 thread. I believe it may be pushing it but within spec.

My understanding is the 130/21 needle is used for the top end of V92 thread while a #22 needle is the bottom end of V138 thread. I would suggest you try V92 thread with the #21 and see what happens or move up to a #22 needle. Also I am assuming you using a older PFAFF 1245 and using the correct needle for your sub class which would be either 134 -35 needle system or a 190 needle system in a leather point not a fabric point needle. As a note the older PFAFF can only accept a 140 / #22 needle with a max thread of 15/3 which is about T120 depending on thread type (cotton vs bonded polyester vs bonded nylon) and thread manufacturer this I think may cause problems with V138 particularly when used in both the bobbin and as a top thread. You maybe able to use V138 as a top thread but be limited to V92 in the bobbin depending on the material being sewn.

Having the top thread lay flat on top of you material indicates the upper tension is too tight or the lower tension is too loose. You did say the bobbin is loose and wobbly. Have you done adjusted the bobbin tension by doing the drop test. Note the tension screw only needs to be turned in ever so slight increments like an 1/8 of a turn.

kgg

[jadub]

Thank you for the response kgg. I’ve been using The Thread Exchange for needle and thread sizing. Here they show 138 working with needles from 125/20-140/22 unless I’m reading it wrong. It wouldn’t be the first time. I’ve actually taken the machine to 3 technicians for service and they say my setup is okay. Of course each time the machine only works for a short time after they’ve worked on it before I have trouble again.

[kgg]

1 hour ago, jadub said:

Here they show 138 working with needles from 125/20-140/22 unless I’m reading it wrong.

Yes you are reading the chart correctly but I think most of the charts are meant for sewing in fabric rather then leather or sticky material. You may find the chart by Toledo Sewing Machines (www.tolindsewmach.com/thread-chart.html ) a better choice.

kgg

[Wizcrafts]

The chart that shows a #20 or 21 needle for use with #138 thread would only work if the bobbin thread is a size smaller. Thus, you could have #138 on top with #92 in the bobbin. The bobbin tension would need to be increased to keep the knots from showing on top.

[jadub]

Wow, thank you guys! I’ll give that a try. I would be so happy if this worked out. I already ordered 140/22 needles. Can’t wait to give them a go. 

[jadub]

Thank you for the input. Got my new needles this morning and tensioned my machine accordingly and it’s much better. I also finally realized I was using junk thread I had accidentally bought. Compared to the thread brands sold by Thread Exchange, Amman, A and E and Filtec, there is a clear visual and tactile difference. Filtec is even a little less stiff than the other two. I know this is a frequent question but since the thread was a big part of my problem. Does anyone have a favorite brand of bonded nylon they want to mention here? 
Thanks again!

[kgg]

53 minutes ago, jadub said:

Does anyone have a favorite brand of bonded nylon they want to mention here? 

I like American & Efird ( http://www.amefird.com/  ) made in both Canada and the US. Lots of choices for all types of sewing. They seem to have done the engineering on their thread. The drawback for some users is that the last I heard before the China Cough shutdowns was that they had stopped producing the 8 ounce spools.

kgg

[jadub]

I got some AandE from Thread Exchange. Good stuff so far. Thank you. And thank you for your help. You turned a waste of a week trying to make my machine work properly into a successful week during which I made my machine work properly.

[kgg]

1 hour ago, jadub said:

AandE from Thread Exchange

In Canada and I'm going to assume the US we can order directly from A&E.

kgg

[jadub]

I looked into the link you sent. I missed the  shop link. I’ll  dig around some more for it. Yesterday I realized Bob at Toledo sells thread though and I like to support him. He’s nicer than most of the reps I have in my area and I like to supposed nice business people. Thank you for the info though.