This is a little stand I made for my wireless charging fossil q marshal. The inner radius is 13mm, the next one out is 18mm, and the outer radius is 21mm. The penny charger is 5mm thick, and the outer lip that the watch sits in is 1.5mm high. The watch sits in the recessed portion on top of the wireless penny charger. I didn't spend much time tweaking this one to look good...
I printed this upright (how it would be used) with supports. I'm not sure if there's a better way. This is only tested to work with the fossil q marshal but it's possible that other chargers and watches fit, just have to measure!