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The final version secures the drum base to the horizontal SS chain plate pin using a 7/8th inch long by one inch wide by 1/8th inch thick SS bar. The drum now is in proper alignment with the double line and will not rotate. This is what Hunter should have done instead of the SS U bolt that allowed the drum to rotate.
The bar cost $3.50 from our local metal shop, plus a 1/4 inch U bolt and two 5/16th inch bolts with nylock nuts. Altogether the material cost was less than $10. The molded rings on the horizontal pin were spaced at 7/8th inch so that required some grinding in order for the bar to fit.