For all my true engineers out there, I'm a hobbyist. I am working on a home project in which I need the upper body to be able to rotate about the screw's axis that is threaded into a heated insert. I need the bolt torque to be able to be increased or decreased by the user (with an Allen wrench) such that it increases or decreases the friction of the upper body's rotation. The upper body will stay put under a light handling load, but still adjustable when rotated by hand with moderate force. The problem I'm running into is that, after a few turns of the upper body, the screw backs itself off and loosens up until there is no friction at all. I was thinking two Teflon washers under the head and maybe a felt washer between the two bodies? Or maybe instead of two Teflon washers I could use a little thrust bearing in their place? Anyone have any better ideas? I feel like I'm overthrowing this.