Hi guys, normally, if the tension is inconsistent, it is caused by the bobbin tension. Tighten the bobbin tension 1/4 of a turn, (never more than a 1/4 turn, no matter what), which will pull the top thread to the bottom of the leather, then tighten the top tension one full turn. If your machine has two tension assemblies, then tighten both tensions one full turn. If this does not work, call me at 1-866-962-9880 and I will go over a few other things with you. Steve
P.S. Elliot, a 10 pound hammer won't work as well as dropping it out of a third story window!