Fully printable G-Clamp with dovetail connector
I use this to clamp button boxes to my desk when playing racing games. The dovetail lets me swap different attachements on the fly without having to print a clamp for each.
Feel free to change the connector design to suit your specific needs, the one I added angles the part slightly for better viewing angles.
There is a place for a countersunk screw in the base (see image 3). Loosely place a screw that is slightly longer that the part (I use an M3x6) and fix it with tape at the bottom. This way, the screw will press in the connector when the device is tightened, which secures the connector on the dovetail.