So, I am quoting myself (my ego has no bounds). I did make this. But, after some time, both the HE500s and AKG 702s pads had some deformation. Not permanent, but still bothered me. Grados seem to hang such that contact is minimized, although split cable management is a bit of a pain. Just feedback to others interested.
My solution was to build this.
And thought that I should share. I used 1 1/4 inch black pipe. Flange, six inch nipple and cap. chose it so that headphone weight might have a greater displacement (should be minimal since we are talking about two curved surfaces of differing diameters). The 1 1/4 pipe parts are more expensive than the lesser diameter. I would have chosen 4 inch nipples but my hardware store only had 3 and then 6. I think 4 would have been perfect. Piece of pine, 12 x 1 x 36 inches from the garage.
For now, it is a "prototype." I would want to put this on a more narrow but thicker (for aesthetics) piece of walnut. It could even be a rough piece on the edges. I might adjust it so that it is horizontal. I will put Grados (SR80 and GS1000) on the Codia-copy stand. The AKG's at the top hang from the plastic loops so that the elastic isn't strained while hanging - maybe making the elastic last longer. But, sliding the AKG over the cap required manipulation, not just an "easy slide-on."
I built a standing desk out of black pipe and poplar. works well if you don't have metal working skills.