I have an older Tama Road Pro stand - there is a captive nut on the allen screw held between the nylon threads (which appears to do nothing) but there is also a knurled locking mechanism which tightens the allen bolt and stops it backing off. I assumed that the tripod style Iron Cobra stand was essentially the same as the older Road Pro (but with additional adjustment on pre-tension/height of the footboard) - is yours missing a knurled adjuster?
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