This is a remix of a remix. so i wanted to print this knuckle duster from the day it was released on thingiverse, so i did, buy i couldn't fit the pieces together without them breaking, a short while later I saw this design was remixed and i printed the remix with a bit more success but the same problem stayed. I got tired of this and put the remix into tinker cad and reinforced the joints. To my surprised it worked and now i am sharing it with anybody who want a ninja fold out knuckle duster.
i printed with 0.1mm just because reasons but you could probably get away with 0.2 mm (warning: i have not tried 0.2 mm and i CBA to in the future unless somebody wants me to)