sebb

Hi,

I hope I can get some answers here as the tips found on internet didn't help.

This happens only sometimes and I'd like to know why. As you can see in the photo, it started making a huge knot underneath and the machine was going crazy, could only stop it from the power off button.

Can't blame it on tension or on wrongfully threading the upper thread or bobbin, since it did everything ok with this color until the last part.

Appreciate any help I can get.