First Three Stitches Loose On Topside

[TinkerTailor]

Edit: This is my techsew5100 441 clone I am referring to:

I am not sure what may be causing this, but the last little while, the first three stitches when I start stitching look as if there is no top tension at all, I get 3 big huge loops on the bottom, and then everything starts working great, i could stitch beautifully for miles. Start at a new place and same thing.

I am holding both threads when I start as I always have. I can only get it to start nice by pulling on the top thread fairly hard to take up the tension, and not even hold the bottom thread.

I can actually feel the top thread getting looser and looser in my hand as i hold both threads and start a stitch.

I have tried with the top and bottom tension both high and low, together and opposite of each other.

I thought I may have a to high bobbin tension issue, so i backed it off 3 full turns, and it had no effect, the rest of the stitching got crappy, but the first 3 stitches did the same thing. I balanced the top to the new bottom tension, and get beautiful stitching after stitch 4...

I had a tag of thread hanging out the hole of the bobbin, that wasn't it either. Tried a different bobbin,nope.

I have tried hard and soft leathers. I have tried with the take up spring adjusted way long, and also with no travel at all, and this did not effect the first three stitches.

The only thing i have changed is i am using a schmetz S-point 24 in place of the round point no name 24 the machine came with.

All in all, these needles are stitching miles better than the junk i had, and can not see better needles causing this issue

Btw, I am using 207 bonded nylon into 2 layers of 4-5 oz. I have tried raw veg and chromexcel.

Cleaned the non-existant dirt and lack of debris from the shuttle area.

Could this be a timing issue?

Edited January 7, 2016 by TinkerTailor

[LumpenDoodle2]

Could the needle height be a fraction different, or bent? Pop an old needle back in and see if it cures it.

Also, this is a longshot, but have you checked that the feed dog and presser feet screws are tight.

As you've said, you've checked everything else. Good luck.

[Wizcrafts]

It's another longshot, but try increasing the length of travel of the check spring. This spring keeps the top thread taut until the needle meets the top layer of leather. If the throw is too short, the thread slack increases until the take-up cycle begins.

I normally backtack two or three stitches at the start and end of a sewing job. This locks in the thread and gives more consistent stitches the rest of the way.

Also, make sure that when you initially drop the foot lift, that the top tension disk separator arm drops out of the disks and they close hard on the thread. If it hangs for a few stitches you will have very little top tension until it drops down.