Modern chess set and board

--added 2 different king pieces for easier printing (chamfer, redesign)
--found a mistake in the outer_case models (corrected)

i couldn't find a modern chess piece set i liked so i thought i'd just make one
the chess pieces themselves are designed to allow a hex bolt to be placed inside and a vilt
i don't have a printer yet so if you successfully print this please share the setting used.