LogCabin82

On my Singer 66 treadle, if I go too fast, the thread slips out of the tension disks and eventually I end up with a thread nest underneath. My top stitches seem to be fine, so I知 worried about tightening the tension discs too much, but I知 wondering if they池e just too loose and that痴 why the thread keeps slipping out?

quiltedsunshine

Sometimes, you need an extra thread guide to hold the thread in the tension disks. Especially if you're using a cone thread and feeding it from the back of the machine. You can tape a paper clip to the back of the machine, then feed it through that before threading it the rest of the way.

OurWorkbench

In addition to what quiltedsunshine suggested, are you threading with the tension with the presser foot up?

Does it also come out of the guide above the tension discs? I

s the check spring in the correct position? I was thinking I had seen someone have a problem with the thread coming out of the guide and I can't remember exactly how they resolved it. I was thinking (dangerous sometimes LOL) that they put a piece of foam in the thread guide after threading.

I do not know if you have had the tension assembly apart and cleaned it. Does it have the numbered dial? Here are a couple of links about the tension assembly and there are multiple youtube videos about the 66 tension assembly.
https://mysewingmachineobsession.blo...6-or_2926.html
Singer 66 tension trouble--perfect going slow, loops fast

Janey - Neat people never make the exciting discoveries I do.
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