Do you have a wine-glass rack? Do you have more coffee cups to store than wine glasses? Well here you go, a simple little gadget so you can hang your coffee cups on your wine-glass rack. Simply slide the smaller side onto the metal rods in the same manner you'd slide a wine-glass onto the rack, then hang your coffee cups by their handles on the large protrusions now hanging happily from the rack :)

Motivated some years ago when a similar design failed to meet my needs: Not a wine hook by ConradLParker - Thingiverse