I really like the original i3 mount, especially the way it held the official Pi Zero case! However, I couldn't use this with my Anet A8. I have tripods though, so I thought I'd make an adapter from this awesome case holder to a tripod!
Use a 1/4-20 threaded nut and it should fit right in with some force.
I used Cura's Ironing mode to get a nice finish on the top layer. Drop a 1/4" nut in the hole and you're good to go!