since filament manufacturers don't have any standard design.

my latest spool of white PLA+ filament ("Numakers") was sliding off the AMS Lite spool holder due to the slanted design on the spool.

there was another cool guy who made the holder from scartch to fit all kinds of spools.

but i made this for this specific problem i had.

its a tight fit.

the diameter is 54mm and it reduces it to 50mm

just push it ¾ way into the spool, just a tiny bit sticking out (you dont want to force it) just like in the picture to balance the weight
now its not sliding off my ams lite anymore.

if by any chance you have the same ams lite and Numakers filament, this would def help you.