[drewitgolf]

Use a wing nut, bolt and a few washers instead of a nail. Simply follow the pictures in 2-K#4 and #5 of the sixth edition, not the seventh. The editor of the seventh edition forgot to put in where the bolt (Hinge Pin Left Wrist) goes. It is one of the cheapest, most effective training aids you will ever have. I use it with EVERY student that I teach.

Use 1 1/2" X 3/4" wood with the Left arm portion measuring 20" and the swingle measuring 36". I also put a bolt in the swingle to allow it to only go to the "Level" condition, unless I loosen the bolt to allow it to go fully "Uncocked".