This is a stand holder to keep your Echo Buttons organized. The design is based around the principle that you'll probably keep them relatively close to your Echo, and thus as round as it is.
I've adjusted this to have relatively tight tolerances (0.5mm) such that when you snap in each plate, it should firmly lock and not really wiggle, you mileage may certainly vary with each print, but it probably won't ever come out without breaking :)
Print one (1) stand and three (3) plates (or just one (1) plate if you are making the small version). Put your buttons on them, it'll be like they sit right there and don't move!
AnyCubic Delta Linear Plus
While there is no need for supports, you might have some small amount of stringing for the overhang on each plate. I carved this off with my razor knife with no issue.