Aluminum bed nut traps

I did this for my Makerfarm 8" i3v, but I'm sure it'll work for other aluminum print beds. As you can see this trap has a lip on the top so you don't have to hold it on. It may fit a little tight, depends on exactly how thick you plate is, I designed it for 1/8" thick. I don't remember which of the 2 stl files I used so I uploaded the both.

You will need longer screws unless you really collapse the springs.