Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:3504036.
I printed out a Hero Me Gen2, and the old camera mount (that clipped on) would stop the x-axis endstop from activating. I made this remix to simply attach the camera to the screws behind the QR code sticker on the Ender 3. Had to buy some M3 x 45mm screws from Home Depot for $1.24, since the stock screws were too short. I also needed 2 washers on each screw because the new ones were slightly too long.
This is just a replacement arm, print out the original's camera parts to hold the actual camera board.
Bonus: if you have an extra stepper motor damper, you can use it on the camera.
3/21/19: added a flipped model in case you want the camera slightly higher up rather than lower.