This is a pan and tilt unit designed around Runcam's new HD camera, the 3S. It also holds a micro FPV camera along side the HD cam so the pan and tilt together. (I prefer using a separate FPV cam) The tilt servo will stick to the bottom of the main piece with servo tape and uses a simple linkage, while the base mounts onto a servo arm, and directly to a GWS S125-1T pan servo. I printed a number of these getting the fit just right on my printer that should be calibrated well, as far as I know. It has only been tested on the ground, but I see no reason it won't work in the air... lol
I printed this with 3 outer walls, 0.48mm extrusion width. I printed both parts with no support, the camera piece should be printed face down on the bed, while the base is printed upright the way it's normally mounted. I didn't need any supports, although there is some bridging on the camera part. Mine printed fine with no support, but it should also work fine with support if needed, depending on your printer and filament.
I used some tapered head counter sunk M3 screws in the tilt axis, the camera piece is made to insert one from the inside with a locking nut on the outside of the base, and the other inserts from the outside of the base and is a tight fit into the plastic, which acts like a locking nut of sorts. Adjust those screws to take out as much slop as possible, while not tight enough to make the tilt stiff. The base is mounted to a servo wheel/arm or whatever you choose. The HD cam slides in from the back, and there are little slots in the back for zip ties. I used one tie as a strain relieve for the flight camera cable, and use the other tie as a sort of locking "pin" to hold the camera in. It's tight enough that it stays in place with friction alone, and will not let the camera fall out.