Summary

Designed to be easy to print and assemble (basically no assembly, just slide the two parts together).

Top 'pin' is 14.9mm wide and 3mm thick, fits the AOS 7 EVO perfectly, might fit other frames where the top holding part fits, angle might be different depending on the drone's shape.
You can resize the whole thing so its smaller.
I printed it on a 300x300mm bed, it, 263x149mm, but even with clever rotation needs at least 250x250 build plate (of course a resized one can be printed on a smaller machine).

Print both parts flat on the bed ('front' has filleted top, so make sure to print it with the flat side down, should be default. Main is non-directional, both sides are fine).

Recommended to print from a more rigid material for a bit more stiffness. Also more walls help (and walls are better than infill).

F3d file included, feel free to modify it for your needs.