This is just a small, easy to print thing to mount a the excellentXiaomi Yi to your zmr250 top plate.
It replaces the existing camera plate entirely. You put the rubber feet between the bottom part and your ZMRs top place, add two zip ties and you are good to go.
The thing is made up of two parts, which makes it a) very easy to print (no overhangs, small footprint) and b) should allow others to remix this for other cameras like a gopro or a sj4000. I added the sketchup file in case anyone is interested in remixing it.