The Ender 3 Pro has many differences from it's standard counterpart, one of which is a broader Y axis shaft. Because of this, I had to break parts off of Dauler's version to get it to attach, making it unstable.
I couldn't just scale it up, because the modular part would scale with it, so I had to remake it.
Haven't actually printed it yet (I have a 16 hour print in progress) but I figured I would put it out there in case someone wants to try it before I finish.
Uses an M5 Nut and Bolt (20mm) to attach.
Update 5 April 2019:
Finally printed. It's pretty snug, but slides right on to the end of the y shaft. The nut also is a pretty snug fit, but I got it to pop in with some light pressure. It's definitely not gonna fall out. Only issue I see is that when I was adjusting the angle of the camera, it pulled up a little easy, which could cause it to break. As long as you don't do that, it should be structurally stable. Printing it on it's side might be better for strength there, but it would lose strength on the outer grips.
Ender_3_Pro_Camera_Modular_Y_Mount.stl | 50.2KB |