Router bit holder capable of holding both ¼" and ½" shank bits. It's designed to fit into a 5/8" hole that's been drilled into plywood or other material. Fits somewhat snug in ¾" plywood but you could probably glue it in place. Hole in bottom helps prevent build-up of sawdust in holder.

Note: Tested fit is slightly loose so you don't run the risk of slicing open your fingers while trying to pull out something like a straight/mortising bit. So, don't try to use it to hold bits horizontally.

Print at 0.2 mm height, 15% infill. Be sure to orient upside down so you can print without any needed supports.