buckle tweak

this is a slight remix of the improved buckle here: https://www.thingiverse.com/thing:3415522
it has the female sized for 50mm straps but with thicker top and bottom walls for more durablity as https://www.thingiverse.com/doumas wanted in the comments, along with a default sized female with thicker and stronger sides as https://www.thingiverse.com/NilsR complained about. there is also the male part sized to 50mm strap size to use with the female thicker walls.stl file for convenience so you dont have to find the original and size it yourself. print with default tree supports with the setting to support on build plate only to make them significantly easier to remove, it should be able to support it well enough but it may depend on your printer. if it cant print like that then disable build plate only and good luck getting those supports out. have fun.