After searching the web tirelessly for just the right ender 3 webcam mount, I said screw it and decided to just make my own. It sticks far enough out that you can see the WHOLE bed which apparently not a lot of people value looking at most mounts out there! Mounts right on your x axis motor (You will need 4 M2.5x45 screws as the stock screws are not long enough). You will also need 1 M2.5X35 and 1 M2.5X30 (If you don't want it to stick out to far) bolts And 2 M2.5 Nuts for the camera mount part.
For Camera assembly instructions check out the original thingiverse file (you will need additional hardware): https://www.thingiverse.com/thing:4336930
Should be able to print on any ender 3 with no supports (possibly a brim or mouse ears though) with relatively high infill (50%+) to prevent vibrations from the printer out of a solid material (ABS, PETG, PLA)
The author remixed this model.
I stumbled across andlod's case for the c270 and fell in love, deciding that it would make the arm complete as an assembly and not just a big ol' ugly arm with a webcam on it. The manual focus ring is a GAMECHANGER as it actually allows you to get the nozzle / part in focus for great timelapses!