Based on a design posted to thingiverse by Codemonkey1973.
I like his design because it rides the Z-axis as a print progresses, but his arm is too short for the FOV of some of my cameras, and the adjustment of the camera angle on his design is very limited.
My design is not a remix, per se, but was designed specifically for my C-Mount Lens Camera Case after I copied the Codemonkey1973 mounting scheme, minus the flange on the Z-axis mounting end.
This design was completely remodeled in Autodesk Inventor to have more than double the length when the extension arm is fully extended.
I also added a set of universal pivots that can be duplicated and combined to create articulation in any possible direction.
These are assembled using M3 x 8mm and M3 x 16mm socket head screws, and I recommend acetone hardening of ABS prints if you have any doubt the strength of your layers. Mine are fine without acetone, but I do use it to bond one of the pivots to the back of a camera case.
The screw hole in the extension arm is extra deep, so have fun digging out support material if you use it, but I have made several of these and I must say that it is possible if you try hard enough. Otherwise, just pull out what you can and let the screw compress the rest back into the hole.
Because I eliminated the flange on Codemonkey1973's design, I was worried about vibration causing blurred images during the more violent printing activities, such as during high-energy gyroid infills or wall-stitching, but this really hasn't been a problem, and since my time lapse snapshots happen at a Z-layer change, the arm settles down enough to capture sharp images.