Bottom stich to tight - Juki lu-563

[stor]

My top stitches look great but bottom stitch is to tight and cuts into my leather when I loosen the top stitch nothing really happens except that the loop shows up in the bottom.
Or maybe I'm using the wrong size needle? 
Or am i just being picky about how it looks?
Using a Juki lu-563 - #15 thread and size 160 needle

[ensitmike]

I had a similar looking bottom stitch. Switching to a diamond point leather needle cleaned up the stitch a lot. 

Was this by chance stitched with a standard needle?

[Wizcrafts]

If the knots or loops are constantly showing on the bottom, back off the bobbin tension spring a half turn at a time until they are centered in the leather. If the knots always show on one side or the other, the thread is too large for the thickness being sewn. In that case you need to use a smaller thread on the bottom, or on both sides, along with a smaller needle.

[stor]

5 hours ago, Wizcrafts said:

If the knots or loops are constantly showing on the bottom, back off the bobbin tension spring a half turn at a time until they are centered in the leather. If the knots always show on one side or the other, the thread is too large for the thickness being sewn. In that case you need to use a smaller thread on the bottom, or on both sides, along with a smaller needle.

the problem isn't the knot, the problem is that the bottom stitch is tighter and digs into the leather more than the top stitch.

 

14 hours ago, ensitmike said:

I had a similar looking bottom stitch. Switching to a diamond point leather needle cleaned up the stitch a lot. 

Was this by chance stitched with a standard needle?

Looked a lot worse with a TRI needle, using a RTW now, couldn't find any S.

[Wizcrafts]

38 minutes ago, stor said:

the problem isn't the knot, the problem is that the bottom stitch is tighter and digs into the leather more than the top stitch.

Did you back off the bobbin spring tension screw? The bobbin tension shouldn't be so tight that the top tension causes the thread to  snap as it goes around the bobbin case/shuttle. Too much bottom tension needs to be offset by excessive top tension. This causes the thread to dig in more. Back off both tensions and rebalance the knots.

[stor]

On 1/6/2019 at 12:55 AM, Wizcrafts said:

Did you back off the bobbin spring tension screw? The bobbin tension shouldn't be so tight that the top tension causes the thread to  snap as it goes around the bobbin case/shuttle. Too much bottom tension needs to be offset by excessive top tension. This causes the thread to dig in more. Back off both tensions and rebalance the knots.

Thank you ! that fixed it and i went with a smaller needle aswell to get less blowout.

/P