Cracker;
The thread tensioner that Cabella's and many others sell runs the thread a couple of ogee shaped washers with a conical compression spring to adjust the tension. I've used this type by drilling a 5/16 hole in my wrapping bench and pressing it in place. However, this type of tensioner likes to put "Fuzzies" in the thread and I've stopped using them. I wish I could find conical compression springs and make my own tensioners!!